iii

EXECUTIVE SUMMARY

In 1999, field studies of the endangered Hawaiian monk seal (Monachus

schauinslandi) were conducted at all of its main reproductive sites in the Northwestern

Hawaiian Islands. These studies provide information necessary to identify and mitigate

factors impeding the species recovery by evaluating (1) the status and trends of monk seal

subpopulations, (2) natural history traits such as survival, reproduction, growth, behavior,

and feeding habits, and (3) the success of various activities designed to facilitate

population growth. 

Results of these studies are best described on a site-by-site basis, and the

information presented in this document is organized accordingly. Pooled site-specific

data, however, provide useful indices of the status and trends of the species as a whole,

including the total number of pups at the main reproductive sites, the total of the sitespecific mean beach counts, and the size composition of the seals observed during the

counts (Fig. 1).

Since 1983, the number of pups born at the main reproductive sites (excluding

Midway Atoll) has been highly variable, and the variability has been largely determined

by the number born at French Frigate Shoals (Fig. 1a), the largest subpopulation. In

1999, 231 pups were counted at these sites, 92 of which were born at French Frigate

Shoals. Record numbers of pups were born at Laysan Island, Lisianski Island, and

Midway Atoll. Mean beach counts, excluding pups, from the main reproductive sites

(again, excluding Midway Atoll) totaled 375 seals and have remained essentially

unchanged since 1993 (Fig. 1b). 

From the mid-1980s to the mid-1990s, adults and pups have comprised a growing

portion of the animals counted (Fig. 1c) and, in 1999, the composition of the counts

remained predominately adults and pups. This composition bodes poorly for

reproduction in the near future if older adult females are not replaced by young females

reaching reproductive age. High mortality of immature seals appears to have led to the

shift in composition, particularly at French Frigate Shoals.

In 1999, three management activities were conducted by the Marine Mammal

Research Program (Honolulu Laboratory, National Marine Fisheries Service) and

cooperating scientists to enhance recovery of the species. First, debris capable of

entangling seals was removed from all study sites and 18 entangled seals were

disentangled by field biologists. Second, debris was removed from coral reefs at

Lisianski Island, Pearl and Hermes Atoll, and Midway Atoll to reduce hazards to the seals

and assess the extent of reef debris fouling. Third, a beach monitoring and public

education program was conducted at Midway Atoll to quantify and mitigate human

impacts on seals.
iv

In this document these and other field studies conducted during 1999 are

described. The format followed is intended to provide complete, standardized, and timely

summaries of the research activities and findings at each study site. The ready

availability of such information is essential for ongoing efforts to stop the decline of this

species and enhance its recovery.

vii

CONTENTS

Page

CHAPTER 1. GENERAL INTRODUCTION ................................. 1

MATERIALS AND METHODS ..................................... 3

Censuses and Patrols ........................................ 3

Reproduction .............................................. 4

Factors Affecting Survival .................................... 5

Individual Identification ...................................... 6

Measurements of Seals ...................................... 7

Samples Collection ......................................... 7

CHAPTER 2. THE HAWAIIAN MONK SEAL ON

FRENCH FRIGATE SHOALS, 1999 ....................................... 9

RESEARCH .................................................... 11

Censuses and Patrols ....................................... 11

Individual Identification ..................................... 11

Samples Collection ........................................ 11

Special Studies ............................................ 12

Health, Disease, and Foraging Ecology Studies ............ 12

Weaned Pup Study .................................. 12

Adult Male Habitat Use Study .......................... 12

Prey Availability .................................... 12

RESULTS ..................................................... 13

Subpopulation Abundance and Composition ..................... 13

Reproduction ............................................. 13

Interatoll Movement ........................................ 13

Factors Affecting Survival ................................... 13

ACKNOWLEDGMENTS ......................................... 13

TABLES ....................................................... 15

CHAPTER 3. THE HAWAIIAN MONK SEAL ON

LAYSAN ISLAND, 1999 ............................................... 23

RESEARCH .................................................... 25

Censuses and Patrols ....................................... 25

Individual Identification ..................................... 25

Samples Collection ........................................ 26

RESULTS ..................................................... 26

Subpopulation Abundance and Composition ..................... 26

Reproduction ............................................. 26

Interatoll Movement ........................................ 27

Factors Affecting Survival ................................... 27

ACKNOWLEDGMENTS ......................................... 27

TABLES ....................................................... 29
(CONTENTS, continued)

Page

viii

CHAPTER 4. THE HAWAIIAN MONK SEAL ON 

LISIANSKI ISLAND, 1999 .............................................. 36

RESEARCH .................................................... 38

Censuses and Patrols ....................................... 38

Individual Identification ..................................... 38

Samples Collection ........................................ 39

Special Studies ............................................ 39

Male Aggression Towards Weaned Pups ................. 39

Large Scale Marine Debris Removal from Reefs ........... 39

Noteworthy Events ......................................... 39

Observed Adult Male Aggression Towards Adult Females ... 39

Adult Male Interactions with Mother-Pup Pairs ............ 40

RESULTS ..................................................... 40

Subpopulation Abundance and Composition ..................... 41

Reproduction ............................................. 41

Interatoll Movement ........................................ 41

Factors Affecting Survival ................................... 41

ACKNOWLEDGMENTS ......................................... 41

TABLES ....................................................... 43

CHAPTER 5. THE HAWAIIAN MONK SEAL ON

PEARL AND HERMES ATOLL, 1999 .................................... 51

RESEARCH .................................................... 53

Censuses and Patrols ....................................... 53

Individual Identification ..................................... 53

Samples Collection ........................................ 53

Special Studies ............................................ 53

Large Scale Marine Debris Removal from Reefs ........... 53

RESULTS ..................................................... 54

Subpopulation Abundance and Composition ..................... 54

Reproduction ............................................. 54

Interatoll Movement ........................................ 54

Factors Affecting Survival ................................... 54

ACKNOWLEDGMENTS ......................................... 54

TABLES ....................................................... 55
(CONTENTS, continued)

Page

ix

CHAPTER 6. THE HAWAIIAN MONK SEAL ON

MIDWAY ATOLL, 1999 ............................................... 63

RESEARCH .................................................... 65

Censuses and Patrols ....................................... 66

Individual Identification ..................................... 66

Samples Collection ......................................... 66

Special Studies ............................................ 66

Health, Disease, and Foraging Ecology Studies ............ 66

Emergent Reef Surveys ............................... 66

Prey Availability .................................... 67

Reef Surveys for Eels, Lobsters, and Octopus .............. 67

Large Scale Marine Debris Removal from Reefs ........... 67

Noteworthy Events ......................................... 68

Beach Monitoring and Public Education .................. 68

RESULTS ..................................................... 68

Subpopulation Abundance and Composition ..................... 68

Reproduction ............................................. 68

Interatoll Movement ........................................ 68

Factors Affecting Survival ................................... 68

ACKNOWLEDGMENTS ......................................... 69

TABLES ....................................................... 71

CHAPTER 7. THE HAWAIIAN MONK SEAL ON

KURE ATOLL, 1999 ................................................... 79

RESEARCH .................................................... 81

Censuses and Patrols ....................................... 81

Individual Identification ..................................... 82

Samples Collection ........................................ 82

Noteworthy Events ......................................... 82

Impacts of Paradise Queen II Grounding ................. 82

Photographic Observation and Seal Disentanglement ........ 83

RESULTS ..................................................... 83

Subpopulation Abundance and Composition ..................... 83

Reproduction ............................................. 83

Interatoll Movement ........................................ 83

Factors Affecting Survival ................................... 83

ACKNOWLEDGMENTS ......................................... 84

TABLES ....................................................... 86
(CONTENTS, continued)

Page

x

CHAPTER 8. THE HAWAIIAN MONK SEAL ON

NIHOA AND NECKER ISLAND, 1999 .................................... 94

RESEARCH .................................................... 96

Censuses and Patrols ....................................... 96

Individual Identification ..................................... 96

Samples Collection ........................................ 96

RESULTS ..................................................... 97

Subpopulation Abundance and Composition ..................... 97

Reproduction ............................................. 97

Interatoll Movement ......................................... 97

Factors Affecting Survival ................................... 97

ACKNOWLEDGMENTS ......................................... 97

TABLES ....................................................... 98

REFERENCES ...................................................... 102

APPENDIXES ........................................................ 107

Appendix A.--Reports summarizing annual field research on the Hawaiian

monk seal by the National Marine Fisheries Service and

collaborating scientists . ..................................... 109

Appendix B.--Hawaiian monk seal census form and 1999 census form

directions. ................................................ 115
CHAPTER 1. GENERAL INTRODUCTION

3

The endangered Hawaiian monk seal (Monachus schauinslandi) hauls out and

breeds in the Northwestern Hawaiian Islands (NWHI, Fig. 1.1). The National Marine

Fisheries Service (NMFS) is the lead agency responsible for the recovery of the Hawaiian

monk seal. Each year the NMFS Southwest Fisheries Science Center, Honolulu

Laboratory, Marine Mammal Research Program conducts studies at the main breeding

sites to provide information necessary to evaluate (1) the status and trends of the monk

seal subpopulations, (2) natural history traits such as survival, reproduction, growth,

behavior, and feeding habits, and (3) the success of various activities designed to

facilitate population growth.

The Marine Mammal Research Program began research on Hawaiian monk seals

at most major reproductive sites in the NWHI during 1981 (Kure Atoll, Laysan Island,

and Lisianski Island), 1982 (French Frigate Shoals (FFS) and Pearl and Hermes Atoll),

and 1983 (Midway Atoll). Nearly every year thereafter, field camps were established for

periods of several days to 9 months to monitor and enhance the recovery of this species. 

Limited population monitoring has also been conducted at Nihoa and Necker Islands,

where subpopulations appear to be limited to a small number of animals by availability of

haulout area. Reports summarizing past NMFS research are listed in Appendix A.

In 1999, Hawaiian monk seal research activities included (1) conducting beach

counts (censuses), (2) tagging weaned pups and other seals for permanent identification

and retagging animals to maintain identification, (3) identifying other seals by previously

applied tags and by natural or applied markings, (4) monitoring reproduction, survival,

injuries, entanglements, interatoll movements, disappearances, and deaths, (5) performing

necropsies, (6) collecting scat and spew samples for food habits analysis, (7) collecting

skin punches and shed molt samples for a DNA tissue bank, (8) collecting placental

samples for histological and bacteriological examination and hormonal studies, (9)

disentangling seals, and (10) inventorying and removing debris capable of entangling

seals. Location-specific objectives and summaries of data collected during the 1999 field

season are described in the following chapters. Much of the information presented in this

memorandum is incorporated into larger data sets for additional analysis and publication

elsewhere. Research was conducted under the authority of the following permits: Special

Use Permits HWN-01-99 and HWN-04-99, and Marine Mammal Permit 848-1335.

MATERIALS AND METHODS

Censuses and Patrols

The primary means of data collection were censuses and patrols. Censuses

consisted of timed, standardized beach counts during which an entire island or atoll was

surveyed for seals. Although data were collected on all seals, those that were in the

water, captive, or dead were excluded from the beach count totals. Identified individuals
4

were counted only once if they were resighted during the survey. The resulting counts did

not reflect total population size but provided an index of population size for comparison

among years and locations. Data collected on each seal observed during censuses

included size class (ranging from pup, juvenile, subadult, and adult size as described in

Stone, 1984 and Appendix B); sex; location on the island; beach position (indicating

whether the seal was in the water or on land); body condition (a subjective estimate; e.g.,

fat, medium, or thin); identification information (permanent or temporary identification

numbers and tag numbers); molting status (an estimate of the percentage an animal had

molted); and disturbance index (the extent that the observer disturbed the seal). Further

data were collected if any of the following events occurred: (1) factors affecting survival

(e.g., entanglements, mobbings, or shark injuries), (2) animal handling, (3) photography,

and (4) documentation of tag condition (e.g., good or broken). In addition, behavioral

data (seal associations and interactions) were collected on Laysan and Lisianski Islands. 

A sample census form and guidelines for its completion are included in Appendix B. 

Censuses were conducted once at Nihoa Island, twice at Necker Island, and every 4 to 8

days (at all other locations), starting at 1300 Hawaii standard time when possible, using

census methods and criteria outlined in Johanos et al. (1987). Atoll-wide counts for

locations with more than a single island (French Frigate Shoals, Pearl and Hermes Atoll,

Midway Atoll, and Kure Atoll) were completed within a 2-day period. The perimeter of

each study area was divided into sectors to facilitate the analysis of data and detection of

demographic trends in different geographic areas. Census methods specific to each

location are detailed in the following chapters.

Patrols consisted of untimed surveys of an entire island perimeter. Information

collected during patrols was similar to that collected during censuses. Because patrols

were not timed, observers concentrated on documenting adult and subadult behavior,

identifying and marking individuals, and collecting scat and spew samples. Islandspecific standardized patrols were conducted at some locations and are described in the

following chapters. 

During all observation periods (i.e., censuses, patrols, and incidental sightings),

observers attempted to minimize seal disturbance by walking above the beach crest and

using vegetation as a visual barrier. On census days, activities which could disturb the

animals and bias the count were not conducted until after the count was completed. 

Additionally, the following were recorded whenever observed: (1) births, pup exchanges,

and weanings; (2) mating activities, adult male aggression, and post-mobbing

aggregations (defined below); (3) entanglements in marine debris; (4) injuries; and (5)

deaths.

Reproduction

Parturient females were identified when possible, and birth and weaning

information was recorded. Because parturient females will nurse pups other than their

own (Boness, 1990; Boness et al., 1998), efforts were made to identify pups and

document changes in nursing relationships from birth to weaning. A pup exchange
5

occurred when the pups of two lactating females were switched or one nursing female

suckled multiple pups. Typically, such exchanges occur during an aggressive interaction

between the two females. On other occasions, a mother and pup become separated, and

one or both seals then actively seek and obtain another nursing relationship (Boness,

1990).

The average nursing period was calculated for some or all pups at each location. 

Nursing periods could not be determined for pups weaned or born prior to or after the

conclusion of full research effort. The average lactation period of parturient females was

also calculated for seals at FFS because higher population density and frequent pup

exchanges (Boness, 1990; Boness et al., 1998) made it difficult to track individual pups

and determine their nursing period. Nursing or lactation periods were defined as the

number of days from birth until the end of the last nursing relationship. Temporary

breaks (e.g., if a mother and pup became separated and one or both seals subsequently

obtained another nursing relationship) were not subtracted from the total. When the exact

birth or weaning date was not known, but occurred within a range of 4 days or less, then

the midpoint of that range was used as the start or end date for calculation of average

nursing or lactation period. Nursing or lactation data were not used if the range exceeded

4 days, or if the pup died or disappeared before weaning.

Factors Affecting Survival

The origins of a wide range of injuries were distinguished based upon

characteristic wound patterns described in Hiruki et al. (1993). Injuries were documented

if they were related to mounting or entanglement or if they were considered severe

enough to possibly affect survival. Injuries were considered severe, and were

summarized if they consisted of (1) three or more abscesses, each <5 cm in diameter, or

one abscess with a diameter >5 cm; (2) an amputation of a minimum of half a flipper

(either foreflipper or hindflipper); (3) a minimum of three punctures or gaping wounds, if

largest dimension was <5 cm, or one gaping wound with a maximum diameter-largest

dimension >5 cm; or (4) densely spaced (overlapping) scratches, abrasions, or lacerations

covering an area equivalent to half the dorsum, or evidence of extensive underlying tissue

damage (e.g., an uneven or darkened surface of the injured area, leaching fluids, or

impaired seal movement). Major healed injuries that had been incurred since the

previous season were documented but not included in summaries.

A seal was listed as dead if its death or carcass was observed. Deaths summarized

here include carcasses found at the beginning of the field season if the seal had clearly

died during the calendar year. A seal was listed as probably dead if it sustained severe

injuries or was emaciated (with skeletal structure clearly evident) and subsequently

disappeared. In addition, one of the following conditions must have been satisfied to

place a seal in the "probably dead" category: (1) the seal was lethargic, had difficulty

moving, or floated listlessly in the water, and disappeared more than a week before the

end of data collection for the field season, or (2) the seal was in deteriorating condition

(loss of weight, enlargement of abscesses, sloughing of skin) and disappeared a minimum
6

 

1Reference to trade names does not imply endorsement by the National Marine

Fisheries Service, NOAA.

of 10 surveys or 1 month before the end of data collection for the field season (whichever

was longer). Nursing pups were listed as probably dead if they disappeared within 3

weeks of birth.

Mobbing and other mating-related male aggressions were observed and recorded. 

By definition, mobbing occurred when multiple males attempted to mate with a single

seal, usually an adult female or immature seal of either sex, causing injury or death of that

seal (e.g., Alcorn, 1984). Mating-related aggression was defined as any incident where an

adult or subadult male repeatedly bit the dorsum, attempted to mount, and tried to prevent

the escape of another seal. These incidents were summarized in this report if they

simultaneously involved more than one male aggressor or resulted in a minimum of one

puncture or gaping wound (missing skin or extending into the blubber layer) or > 15

scratches to the dorsum or flanks. Post-mobbing aggregations were also summarized:

these were groups of males congregated on the beach, attending a seal with new mounting

injuries as described above.

Individual Identification

During censuses and patrols, individual seals were identified with tags, applied

bleach marks, scars, or natural markings. After weaning, pups were tagged on each hind

flipper with a colored plastic Temple Tag,®1 uniquely coded to indicate island or atoll

subpopulation, year of birth, and individual identification number (Gilmartin et al., 1986). 

In addition, two passive integrated transponder (PIT) tags were implanted subcutaneously

in the posterior dorsum of most weaned pups (see Lombard et al., 1994, for detailed

tagging procedures).

Colored plastic Temple Tags have been applied to nearly all weaned pups since

1981 at Kure Atoll, since 1982 at Lisianski Island, since 1983 at Laysan Island and Pearl

and Hermes Atoll, since 1984 at French Frigate Shoals, and since 1995 at Midway Atoll. 

Pups at Midway Atoll, Necker and Nihoa Islands, and the main Hawaiian Islands have

been tagged opportunistically since 1983. Since 1991, PIT tags have also been implanted

subcutaneously in the ankle (1991) or the posterior dorsum (all subsequent years) of most

weaned pups. 

In 1999, untagged immature and adult seals were opportunistically tagged with

Temple Tags uniquely coded to indicate that their ages and birth locations were unknown.

These seals also received PIT tags. Seals with lost or broken tags were retagged to

maintain their identities.

At five locations (Laysan Island, Lisianski Island, Pearl and Hermes Atoll,

Midway Atoll, and Kure Atoll), seals were bleach-marked for individual identification
7

(Stone, 1984), using the solution described in Johanos et al. (1987). Molting seals were

re-marked with bleach to maintain their identities over the study interval. At Laysan and

Lisianski Islands, nursing pups were also bleach-marked prior to the post-natal molt to

facilitate identification during the nursing period.

Tags, scars, other natural markings, and any applied bleach marks were sketched

by hand on an individual scar card for each seal, which was revised throughout the field

season to maintain a current description of the identifying marks of each seal. 

Photographs of scars and natural markings were added to individual identification files

begun during 1981 or 1982, depending on site.

Subpopulation size and composition were determined at locations where

observers no longer encountered unidentified seals, and we assumed all seals were

identified. These statistics included all individuals observed alive at the location during

the interval from March through August and all known parturient females and pups born

during the year. 

The movement of seals between island or atoll subpopulations within and between

years complicates the estimation of subpopulation size and composition. This is

particularly true at Midway Atoll, where a number of the observed seals were tagged at

other locations (primarily Kure Atoll and Pearl and Hermes Atoll). Therefore,

standardized rules for assigning each seal identified to just one subpopulation are applied

as follows. If a seal was observed at more than one location during March-August, it was

included exclusively in the subpopulation where it was sighted nearest to May 15, unless

it pupped or molted at another location. A parturient female was always exclusively

included in the subpopulation where she pupped, and a non-parturient seal was

exclusively included in the subpopulation where it molted. Pups were always exclusively

included in the subpopulation where they were born.

Measurements of Seals

Pups were measured to provide information on condition and to examine the

relationship between body size and survival. Measurements were taken as soon after

weaning as possible, and measurements taken within 2 weeks after weaning were

included in the summaries. Measurements included straight dorsal length (Winchell,

1990) and axillary girth (American Society of Mammalogists, 1967).

Samples Collection

Samples were collected for a DNA tissue bank, pathology analysis, investigation

of food habits, and documentation of marine debris. Tissue punches for DNA were

collected during tagging efforts for all newly tagged or retagged seals and during

necropsies on recently dead seals. Samples of placentas were also collected from recent

birth sites. 
8

For each dead seal recovered, an external examination was made, photographs

were taken, and external measurements and observations were recorded. For a recent

death, an internal examination was made, and samples of tissue, organs, parasites, and

stomach contents were collected. Detailed descriptions of necropsy procedures and

sample collection methods are in Winchell (1990).

Scat and spew samples were collected opportunistically for analysis of food habits

(Alcorn, 1984). These samples were collected from seals of known size and sex class,

when possible. 

Nets, lines, ropes, and other debris capable of entangling seals and turtles were

documented and inventoried. From 1982 to 1998, potentially entangling marine debris

was incinerated on site. Beginning in 1999, due to new Fish and Wildlife Service

regulations, marine debris was not handled in this manner at most sites. At Kure Atoll,

dangerous or entangling debris was destroyed via incineration, following the methods in

Johanos and Kam (1986). At all other locations, debris was cut into manageable pieces

and placed in storage bins or secured piles in centralized locations for subsequent

removal via ship.
9

CHAPTER 2. THE HAWAIIAN MONK SEAL ON

FRENCH FRIGATE SHOALS, 1999

Mitchell Craig, Melissa Shaw, and Jane MacKenzie

11

The largest subpopulation of Hawaiian monk seals is located at French Frigate

Shoals (FFS, lat. 23°45'N, long. 166°10'W), ca. 830 km northwest of Oahu in the

Northwestern Hawaiian Islands. This atoll is part of the Hawaiian Islands National

Wildlife Refuge (Fig. 1.1) and consists of nine permanent islets (Disappearing, East, Gin,

Little Gin, La Perouse Pinnacles, Round, Shark, Tern, and Trig), three semipermanent

islets (Bare, Mullet, and Whaleskate), and several transient sand spits (Fig. 2.1).

RESEARCH

The National Marine Fisheries Service (NMFS) began research on Hawaiian

monk seals at FFS in 1982. In 1999, research was conducted by NMFS during

January 12-February 4 and May 19-December 31. Incidental observations were recorded

by U.S. Fish and Wildlife Service (FWS) personnel during the rest of the year. The

perimeters of the six larger islets were divided into sectors using artificial or natural

landmarks. Research activities specific to this subpopulation in 1999 included (1)

ongoing health, disease, and foraging ecology studies (2) investigation of health,

condition, causes of mortality, and habitat use of weaned pups, (3) investigation of adult

male seal habitat use patterns using seal-mounted video cameras, (4) assessment of

nearshore reef fish abundance, and (5) collection of reef vertebrates and invertebrates for

a Hawaiian monk seal prey fatty acid analysis.

Censuses and Patrols

Atoll censuses (n = 10) were conducted every 8 d, on average, from May 25 to

August 16. Each atoll census began between 1050 and 1220 and ended between 1540

and 1810 Hawaii standard time. Round and Mullet were censused from a boat or on foot,

while the remaining islets were censused on foot by one or two persons. Patrols were

conducted on noncensus days. Frequency of surveys was higher at islets where more

pups were born. Thus Trig, East, Round, and Whaleskate islets were surveyed every 2-4

d and Little Gin and Gin islets were visited every 7-10 d to monitor pupping activity and

factors affecting survival. Patrols of Tern Island were conducted every 2-4 d.

Individual Identification

A total of 428 individuals (336 excluding pups) were identified by existing or

applied tags, scars, or natural markings. Fifty-six weaned pups were tagged with Temple

Tags; 55 of these pups were tagged with passive integrated transponder (PIT) tags. Nine

adult seals (seven male, two female) were tagged, and two juveniles (one male, one

female), seven subadults (four male, three female), and 10 adult seals (six male, four

female) were retagged with Temple Tags. 
12

Samples Collection

Seventy-five scat and spew samples were collected. Skin punches were collected

from 71 seals during tagging. Necropsies were performed on three dead seals found at

the study site. Tissue and skeletal samples were collected from all necropsied seals. In

total, 15 items of potentially entangling debris were inventoried and stored for removal

via ship.

Special Studies

Health, Disease and Foraging Ecology Studies

In January and February, biologists collected blood, fecal samples, and blubber

biopsies from 47 seals (22 adult and 25 immature seals) restrained specifically for

ongoing epidemiological and fatty acid diet studies. Blood, fecal samples, and blubber

biopsies were also collected from four seals instrumented with video cameras for a

habitat use study and from 27 weaned pups during a study of first year survival. The

purpose of this sampling was to obtain baseline information to assess the health, disease

status, and foraging ecology of the Hawaiian monk seal population (Aguirre and Reif,

1998). 

Weaned Pup Study 

From June through September, 53 and 9 weaned pups were instrumented with

VHF radio transmitters and time-depth recorders, respectively, as part of a health,

condition, habitat use, and mortality study. Mass of 50 weaned pups was measured.

Adult Male Habitat Use Study

In July and August, four molted adult males were instrumented with

CRITTERCAMS for 8 to 72 d. The seals were instrumented as part of a habitat use pilot

study conducted in collaboration with National Geographic Television. 

Prey Availability

In August, the Honolulu Laboratory, NMFS, conducted diving transects at nine

stations around FFS to estimate densities of reef fishes. These surveys replicated those

conducted at FFS during 1980-83, 1992, 1995-98 (see DeMartini et al., 1993). In 1998

and 1999 this study was expanded to assess fish abundance at deeper sites (50-60 m). 

The results of this ongoing research will be reported elsewhere. In August and

September, the IRI also collected reef vertebrates and invertebrates for analysis of fatty

acid in potential monk seal prey.
13

RESULTS

Subpopulation Abundance and Composition

The mean (±SD) of 10 atoll censuses was 145.4 seals (±10.4) including pups, and

106.2 seals (±10.1) excluding pups (Table 2.1). The total spring-summer subpopulation

was 405 individuals, 313 excluding pups (Table 2.2). This number is a subset of the total

identified in the calendar year. The numbers of tagged known-age seals born at FFS

during the period from 1984 to 1998 and resighted at any location in 1999 are

summarized in Table 2.3.

Reproduction

A minimum of 92 pups were born at FFS in 1999: 69 were successfully weaned

and 23 died or disappeared prior to weaning (Table 2.4a). One fetus was found in

December 1999. Nursing periods and measurements of weaned pups are summarized in

Table 2.4b. The birth rate, measured as the number of pups born divided by the number

of adult-sized females in the subpopulation X 100 was 63.9% ((92/144) X 100). The

mean (±SD) lactation period for 36 females was 36.6 d (±7.0 d). A minimum of 12 pups

were fostered by mothers other than their own.

Interatoll Movement

Interatoll movement was documented for seven seals that completed a total of 11

movements between FFS and either Necker Island, Laysan Island, or Johnston Atoll

(Tables 2.5a and b).

Factors Affecting Survival

Attacks by large sharks, mounting attempts by male Hawaiian monk seals,

entanglement in marine debris, emaciation, and unknown factors resulted in 85 lifethreatening conditions, which led to the confirmed deaths of 11 animals (all nursing or

weaned pups except one juvenile) and the probable death of 24 seals (all nursing or

weaned pups except one juvenile) (Table 2.6). Three incidents of adult male aggression

were observed; each of these involved a single adult male aggressively mounting and

biting a weaned pup. One such incident resulted in injury to a female pup and is included

in Table 2.6; the other pups (one male, one female) escaped obvious injury. Seven seals

were entangled: one escaped independently and six were released by observers. One

aborted fetus was found on Tern Island in December 1999. In addition, a weaned female

pup was entrapped by the seawall on Tern Island and was guided out to the beach.
14

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife Service, Hawaiian

Islands National Wildlife Refuge staff. We thank the captain, officers, and crew of the

NOAA ship Townsend Cromwell for logistical assistance.
15

TABLES

for French Frigate Shoals
16
17

Table 2.1.--Summary statistics for atoll censuses (n = 10) of Hawaiian monk seals at

 French Frigate Shoals from May 25 to August 16, 1999.

Size/Sex Mean number of individuals Standard deviation

Adults 79.7 5.6

Male 25.1 2.8

Female 52.3 3.5

Unknown 2.3 2.7

Subadults 12.8 4.8

Male 4.9 3.0

Female 7.5 2.4

Unknown 0.4 0.7

Juveniles 13.7 4.9

Male 7.0 3.0

Female 5.5 3.2

Unknown 1.2 0.9

Pups 39.2 5.7

Male 13.3 4.8

Female 11.4 5.2

Unknown 14.5 6.6

Non-pup total 106.2 10.1

Grand total 145.4 10.4
18

Table 2.2.--Composition of the Hawaiian monk seal subpopulation at French Frigate

 Shoals during the spring and summer of 1999. Includes all known parturient

 females and pups born during the calendar year. 

Number of seals

Size Male Female Unknown Total

Sex ratio

male:female

Adults 92 144 0 236 0.6:1

Subadults 12 19 0 31 0.6:1

Juveniles 23 23 0 46 1.0:1

Pups 39 42 11 92a

0.9:1

Non-pup Total 127 186 0 313 0.7:1

Grand Total 166 228 11 405 0.7:1

aExcludes one aborted fetus.
19

Table 2.3.--Summary of tagged known-age seals born at French Frigate Shoals and

 resighted at any location in 1999.

Cohort year

Age

(years) Sex

Number

originally

tagged

Number

resighted

 in 1999

1984 15 Male

Female

49

43

11a

15a

1985 14 Male

Female

48

38

4

a

10a

1986 13 Male

Female

52

48

11a

18a

1987 12 Male

Female

55

51

12

12

1988 11 Male

Female

52

62

5

7

1989 10 Male

Female

51

50

6

7

a

1990 9 Male

Female

38

41

1

8

a

1991 8 Male

Female

24

44

1

5

a

1992 7 Male

Female

36

55

2

9

a

1993 6 Male

Female

40

39

3

2

1994 5 Male

Female

47

48

1

6

a

1995 4 Male

Female

29

26

2

13a

1996 3 Male

Female

39

30

4

4

1997 2 Male

Female

32

19

1

3

1998 1 Male

Female

49

39

27

20

a

 Cohort survivors include seals removed from French Frigate Shoals for rehabilitation or

direct translocation. These seals were either released at Kure or Midway Atoll (n = 19) or

remain in permanent captivity (n = 14).
20

Table 2.4a.--Summary of Hawaiian monk seals born at French Frigate Shoals in 1999.

 Event

Number of pups

Male Female Unknown Total

Born 39 42 11 92

Died/probably died

 prior to weaning

6 6 11 23

Weaned 33 36 0 69a 

Tagged 30 30 0 60b

aThree male and six female weaned pups disappeared before tagging or were severely

injured preventing safe restraint for tagging.

bA weaned female pup, born in 1999, was tagged in February 2000. 

Table 2.4b.--Summary of nursing periods and measurements of weaned pups at French

 Frigate Shoals in 1999. Nursing periods were calculated where both birth

 and weaning date ranges were < 4 d. All measurements were taken within

 two weeks after weaning. 

Nursing period (d)

Axillary

girth (cm)

Straight dorsal

length (cm) Mass (kg)

Mean 38.7 108.1 129.6 70.9

Standard

deviation

8.0 11.7 7.9 18.0

n 5 47 47 41
21

Table 2.5a.--Documented movement of Hawaiian monk seals to French Frigate Shoals

 from other locations in 1999, summarized by movements between two

 locations. No seals made more than one observed trip.

Original location Number, size, and sex class

Necker Island 1 adult male

Laysan Island 2 adult males

2 adult females

Table 2.5b.--Documented movement of Hawaiian monk seals from French Frigate Shoals

 to other locations in 1999, summarized by movements between two

 locations. No seals made more than one observed trip.

Destination Number, size, and sex class

Necker Island 2 adult males

Laysan Island 1 adult male

2 adult females

Johnston Atoll 1 adult female
22

Table 2.6.--Factors affecting Hawaiian monk seal survival at French Frigate Shoals in

 1999. 

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Adult Male

Female

3

5

3

5

0

0

0

0

Subadu lt Male

Female

1

2

1

2

0 0

Juvenile Male

Female

3

2

3

2

0

0

0

0

Weaned pup Male

Female

5

12

5

10

0

1

0

1

Nursing pup Male 

Female 

Unknown 

1

2

1

0

2

0

1

0

1

a

0

0

0

Mounting

Adult Female 3 3 0 0

Weaned pup Male

Female

4

4

b

3

2

1

2

0

0

Entanglement

Adult Female 3

c 0 0 0

Subadu lt Female 1

d

0 0 0

Weaned pup Male 

Female 

2

d

1

d

0

1

0

0

0

0

Emaciated

Weaned pup Female 1

e

0 1 0

Unknown

Adult Female 2 2 0 0

Juvenile Male 2 0 1 1

Weaned pup Male

Female

1

3

0

0

0

0

1

3

Nursing pup Male

Female

Unknown

5

6

10

0

0

0

1

1

1

4

5

9

aObserved being killed and eaten by a Galapagos shark.

bOne wea ned female pup was m ounted, b it, and injured by an aggre ssive male during an o bserved in cident.

cTwo re leased by o bservers an d one freed self.

dReleased by ob servers.

e

Prematurely weaned pup.
23

CHAPTER 3. THE HAWAIIAN MONK SEAL ON

LAYSAN ISLAND, 1999

Brenda L. Becker, Petra Bertilsson-Friedman, and Sheila P. Gummeson

25

Laysan Island (lat. 25°42'N, long. 171°44'W) is located ca. 1,300 km northwest of

Oahu in the Northwestern Hawaiian Islands (Fig. 1.1). This island lies within the

Hawaiian Islands National Wildlife Refuge and is one of the six primary haulout and

pupping locations of the Hawaiian monk seal (Fig. 3.1).

RESEARCH

The National Marine Fisheries Service (NMFS) began research on Hawaiian

monk seals at Laysan Island in 1981. In 1999, research was conducted by NMFS during

March 10-July 25, and incidental observations were recorded by U.S. Fish and Wildlife

Service (USFWS) personnel during the remainder of the year. The perimeter of the

island (ca. 11 km) was divided into 20 sectors using artificial or natural landmarks (Fig.

3.1). Research objectives specific to this subpopulation in 1999 included (1) assessment

of maternity and pup exchanges, and (2) documentation of male behavioral patterns and

aggression, including incidence of mobbing.

 

Censuses and Patrols

Censuses and patrols were scheduled to ensure that the entire island perimeter was

monitored at least once daily during March 30-July 21. Censuses (n = 27) were

conducted by two observers every fourth day from April 8 to July 21, beginning at 1300

Hawaii standard time and continuing for 2.6 to 4.0 h.

Standardized behavior patrols were conducted on 57 noncensus days from March

30 to July 8 to assess activity patterns of adults and large subadults, document male

aggression, and detect mobbing incidents. During behavior patrols, observer attention

was directed out to sea as much as possible as mobbings have been observed most

frequently in the water. Twenty full-island incidental patrols to record noteworthy events

were conducted on noncensus and nonbehavior patrol days. 

Individual Identification

A total of 314 individuals (256 excluding pups) were identified by existing or

applied tags, bleach marks, scars, or natural markings. Bleach marks were applied to 308

seals, including 52 nursing pups. All weaned pups (n = 54) were tagged with Temple

Tags and most (n = 46) received passive integrated transponder (PIT) tags. In addition,

three weaned pups and two two-year-old seals were retagged with temple tags to replace

broken or lost tags.

Samples Collection

One hundred-three scat and 30 spew samples were collected. Skin punches were

collected from 46 weaned pups. Shed molt samples were collected from 13 individuals.
26

Necropsies were performed, and tissue samples collected, from six recently dead seals,

and skulls from three non-neonate carcasses were also collected. Twenty-five placentas

were collected. In total, 727 pieces of potentially entangling debris were inventoried. All

debris items were placed in storage bins for removal via ship, with the exception of two

pieces removed and collected from entangled animals (one from a seal and one from a

seabird), and a third collected for encrustation analysis. Six fishhooks used in

commercial fisheries were found on the beach and collected. 

RESULTS

Subpopulation Abundance and Composition

The mean (±SD) of 27 censuses was 117.2 seals (±19.4) including pups, and 86.5

seals (±13.5) excluding pups (Table 3.1). The total spring-summer subpopulation was

310 individuals, 252 excluding pups (Table 3.2). This number is a subset of the total

identified in the calendar year. The sex ratio for older (>16 years of age) and unknown

aged adults was at unity at ca.1.0:1 (30 males: 31 females), whereas the ratio for younger

adults (< 16 years of age) was ca. 0.8:1 (46 males: 55 females). The numbers of tagged

known-age seals born at Laysan Island during the period from 1983 to 1998, and

resighted at any location in 1999, are summarized in Table 3.3. 

Reproduction

At least 58 pups were born at Laysan Island in 1999: 54 were successfully

weaned and 4 died prior to weaning (Table 3.4a). Nursing periods and measurements of

weaned pups are summarized in Table 3.4b. The birth rate measured as the number of

pups born divided by the number of adult-sized females in the subpopulation X 100 was

67.4% ((58/86) X 100). A minimum of 28 pup exchanges occurred between 25 nursing

females; three of these incidents were observed. In addition, two interventions (a humanassisted pup exchange and human-assisted pup fostering) were performed in efforts to

improve the survival of pups involved. Three births were observed.

Interatoll Movement

Interatoll movement was documented for 13 seals that completed a total of 22

movements between Laysan Island and either French Frigate Shoals or Lisianski Island

(Tables 3.5a and b).

Factors Affecting Survival

Attacks by large sharks, mounting attempts by male Hawaiian monk seals,

entanglement in marine debris, emaciation, and other/unknown factors led to 24 lifethreatening conditions, which resulted in the confirmed deaths of six animals and the

disappearance of two other seals (Table 3.6). Although incidents of prolonged adult male

aggression were not observed, two seals died from unobserved male mounting incidents;

both were injured, and one likely drowned. Three seals were entangled: one escaped
27

unaided, and two were released by observers. An additional seal, wedged in shallow

water rocks, was released by observers. In addition to the incidents presented in Table

3.6, two seals were in poor condition: one adult female has been emaciated for the

previous two seasons, and a juvenile since last year. One weaned female pup was

temporarily oiled with <5% of its pelage surface area affected.

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife Service, Hawaiian

Islands National Wildlife Refuge staff and thank the captain and crew members of the

NOAA ship Townsend Cromwell. Special thanks are extended to Jason Baker, Matthew

Berry, Russell Bradley, Brenden Courtot, Chris Eggleston, Holly Gellerman, Bart

McDermott, Laurie Ness, Cindy Rehkemper, Michelle Reynolds, Patty Scifres, Christina

Sulzman, Mark Vekasy, and Alex Wegmann for their data collection and seal tagging and

disentangling assistance.
28
29

TABLES

for Laysan Island
30
31

Table 3.1.--Summary statistics for censuses (n = 27) of Hawaiian monk seals at Laysan

 Island from April 8 to July 21, 1999.

Size/Sex Mean number of individuals Standard deviation

Adults 54.9 7.1

Male 21.0 3.9

Female 33.6 5.1

Unknown 0.3 0.5

Subadults 17.5 8.7

Male 5.7 2.6

Female 11.8 6.4

Unknown 0.0 0.0

Juveniles 14.1 3.4

Male 8.4 2.6

Female 5.6 1.6

Unknown 0.1 0.4

Pups 30.7 10.6

Male 11.1 4.7

Female 19.4 6.2

Unknown 0.1 0.6

Non-pup total 86.5 13.5

Grand total 117.2 19.4
32

Table 3.2.--Composition of the Hawaiian monk seal subpopulation at Laysan Island

 during the spring and summer of 1999. Includes all known parturient females

 and pups born during the calendar year. 

Number of seals

Size Male Female Total

Sex ratio

male:female

Adults 76 86 162 0.9:1

Subadults 17 30 47 0.6:1

Juveniles 25 18 43 1.4:1

Pups 21 37 58 0.6:1

Non-pup total 118 134 252 0.9:1

Grand total 139 171 310 0.8:1
33

Table 3.3.--Summary of tagged known-age seals born at Laysan Island and resighted at any

location in 1999.

Cohort year

Age

(years) Sex

Numb er originally

tagged

Number resighted 

in 1999

1983 16 Male

Female

10

10

1

6

1984 15 Male

Female

16

13

3

5

1985 14 Male

Female

16

14

2

5

1986 13 Male

Female

15

17

2

2

1987 12 Male

Female

13

15

3

6

1988 11 Male

Female

23

17

5

3

1989 10 Male

Female

16

13

2

2

1990 9 Male

Female

7

9

2

3

1991 8 Male

Female

18

13

8

6

1992 7 Male

Female

18

14

2

4

1993 6 Male

Female

23

14

4

5

1994 5 Male

Female

18

29

8

8

1995 4 Male

Female

16

21

7

11

1996 3 Male

Female

23

21

11

13

1997 2 Male

Female

19

16

10

10

1998 1 Male

Female

Unknown

24

20

1

17

15

0
34

Table 3.4a.--Summary of Hawaiian monk seals born at Laysan Island in 1999.

Event

Number of pups

Male Female Total

Born 21 37 58

Died prior to weaning 1 3 4

Weaned 20 34 54

Tagged 20a34b54

a

Includes two pups weaned and tagged after the NMFS Camp; one of these was also born after the

NMFS camp.

b

Includes five pups weaned and tagged after the NMFS camp; two of these were also born after

the NMFS camp.

Table 3.4b.--Summary of nursing periods and measurements of weaned pups at Laysan Island in

1999. Nursing periods were calculated where both birth and weaning date ranges

were < 4 d. All measurements were taken within 2 weeks after weaning. 

Nursing period (d) Axillary girth (cm)

Straight dorsal length

(cm)

Mean 38.0a107.2 127.5

Standard deviation 4.5 8.7 5.6

n 51 54 54

a

Includes one pup who was initially weaned at 28 days and, with human assisted fostering, weaned

a second time at 54 days of age (including an 8-day break between the two nursing periods).
35

Table 3.5a.–Documented movement of Hawaiian monk seals to Laysan Island from other

locations in1999, summarized by movements between two locations. No seals made

more than one observed trip.

Original location Number, size, and sex class

French Frigate Shoals 1 adult male

2 adult females

Lisianski Island 1 adult male

5 adult females

Table 3.5b.–Documented movement of Hawaiian monk seals from Laysan Island to other

locations in 1999, summarized by movements between two locations. One seal

made more than one observed trip.

Destination Number, size, and sex class

French Frigate Shoals 2 adult males

2 adult females

Lisianski Island 5 adult females

2 subadult females

1 juvenile male

1 juvenile female
36

Table 3.6.--Factors affecting Hawaiian monk seal survival at Laysan Island in 1999.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Adult Female 2 2 0 0

Subadult Female 1 1 0 0

Juvenile Male 1 1 0 0

Mounting by Males

Adult Female 3 2 1 0

Subadult Male

Female

1

1

1

1

0

0

0

0

Juvenile Female 1 1 0 0

Weaned pup Female 1 0 1

a

0

Entanglement

Adult Female 1

b

0 0 0

Weaned pup Female 2

c

0 0 0

Emaciation

Adult Male 1 0 0 1

d

Other/Unknown

Adult Male 2 1 1 0

 Female 1 1 0 0

Weaned pup Male 1

e

0 0 0

Female 1 1 0 0

Nursing pup Male 1 0 1 0

Female 3 0 2

f

1

g

aPup probably drowned during unobserved incident.

bSeal disentangled itself and sustained no injuries from the entanglement.

cBoth seals were released by researchers and sustained no injuries from the entanglement.

dAn older seal in extremely poor and deteriorating condition disappeared.

eSeal wedged in rocks in shallow water was released by researchers; sustainedminor injuries.

fOne pup’s mother was nonresponsive to the pup’s nursing attempts and wouldn’t present her

ventrum; the pup may have starved.

gThe pup disappeared at 22 days old.
37

CHAPTER 4. THE HAWAIIAN MONK SEAL ON 

LISIANSKI ISLAND, 1999

Dorothy M. Dick, Amber D. Pairis, and Lara D. Gibson

39

Lisianski Island (lat. 26°02'N, long. 174°00'W) is one of the primary haulout and pupping

locations of the Hawaiian monk seal. The island is located ca. 1,760 km northwest of Oahu (Fig.

1.1) and is part of Neva Shoal, a shallow reef bank within the Hawaiian Islands National Wildlife

Refuge (Fig. 4.1).

RESEARCH

The National Marine Fisheries Service (NMFS) began research on Hawaiian monk seals at

Lisianski Island in 1981. In 1999, research was conducted by NMFS during March 15-July 20

and on October 12 and 17. The perimeter of the island was divided into 20 sectors using artificial

or natural landmarks (Fig. 4.1). Research activities specific to this subpopulation in 1999

included (1) assessment of maternity and pup exchanges, (2) documentation of adult male

behavioral patterns and aggression (including focal observations in areas frequented by weaned

pups), and (3) large-scale debris removal from reef around the island. 

Censuses and Patrols

Censuses and patrols were scheduled to ensure that the entire island was monitored at least

once daily during March 15-July 20. Censuses (n = 28) were conducted by two observers every

fourth day from March 31 to July 20, beginning at 1300 Hawaii standard time and continuing

from 1.8 to 3.0 h. 

Standardized behavior patrols were conducted on noncensus days to assess activity

patterns of adults and large subadults, to document male aggression, and to detect mobbing

incidents. During these patrols (n = 65), attention was directed out to sea as much as possible

since mobbing has been observed most frequently in the water.

Individual Identification

A total of 207 individuals (174 excluding pups) were identified by existing or applied tags,

bleach marks, scars, or natural markings. All weaned pups (n = 27) were tagged with Temple tags

and passive integrated transponder (PIT) tags. One weaned pup received an additional two temple

tags due to a broken original tag. One immature female seal was also Temple tagged.

Samples Collection

One hundred-one scat and 12 spew samples were collected. Skin punches were collected

from 28 seals during tagging and from four of the dead pups during necropsies. Necropsies were

performed and tissue samples were collected from five dead male pups, all < 7 days old. Skeletal

samples were collected from seven dead seals: one lower jawbone and one skull from two seals,

respectively, whose year of death is unknown, and five skulls from the necropsied pups. Twentythree shed molt samples were collected from 20 individuals. Fourteen placenta samples were also

collected. In total, 707 items of potentially entangling debris were inventoried; 702 items were

stored on Lisianski for removal during a marine debris cruise in October 1999. The remaining 5
40

items were removed from entangled animals (4 from seals, 1 from an albatross chick), collected,

and brought back to Honolulu.

Special Studies

Adult Male Aggression Towards Weaned Pups 

In1999, 2-h focal group and area observations (n = 25) were conducted in areas frequented

by weaned pups. These observations were designed to document the frequency and intensity of

aggressive interactions between adult males and weaned pups and to identify individual male

aggressors. 

Although aggressive behavior was observed during three focal observations, only one of

these incidents involved an adult male; the other two involved subadult males. Interactions

between adult or subadult males and weaned pups were also recorded as part of the standard

census and behavior patrol procedure as well as opportunistically during other surveys. 

Fifteen adult and 6 subadult males were observed interacting with weaned pups on 21

different occasions. Interactions lasted from 30 seconds to 1 h. No incidents resulted in fatalities

and only one incident resulted in obvious injury to the pup. All encounters occurred in the water

close to shore and involved splashing, rolling, and vocalizing between individuals. Most

observations noted the aggressive male attempting to mount or pushing the weaned pup’s head

underwater and holding it there for up to one minute. During several such events the aggressor’s

penial aperture was noted to be protruding beyond resting levels, however sexual organs were not

visible. Occasional biting of the weaned pups also occurred. Two additional, and similar,

encounters occurred between adult males and juvenile seals but did not result in obvious injury.

Large Scale Marine Debris Removal from Reefs

A cooperative multi-agency coral reef cleanup was conducted at Lisianski Island in

October 1999 supported by the NOAA ship Townsend Cromwell and the USCG cutter Walnut. 

Personnel from 11 agencies removed debris to reduce entanglement hazards to monk seals and

other marine life and document the extent of reef debris fouling. Debris collected and stored on

the beaches during the main 1999 field season was also removed. In total, 5,437 kg of debris were

recovered at Lisianski Island: 910 kg from the reef and 4,527 kg from the beaches. 

Noteworthy Events

Observed Adult Male Aggression Towards Adult Females

One mobbing was observed during 1999. The event was already in progress offshore when

first noticed, and the participants moved onshore as it concluded some 3.5 h later. Four males

were initially observed interacting with one female. Intense splashing and several glimpses of

male sexual organs were noted. Two additional males joined onshore events. Beach observations

included various males actively defending the female with numerous male-male contests and

frequent reversal from challenging to defending roles. Also noted were individual males moving

away from the mobbing group for several minutes before actively rejoining the fray. Although the

incident was not fatal to the female, a large open wound developed in her dorsal area, and 23 days
41

later she gave birth to a pup that died perinatally. Later in the season her dorsal injury was reopened in an unobserved incident and it was still healing when researchers left Lisianski. 

In separate incidents, two prolonged harassment episodes were witnessed. In both cases,

behaviors observed were indicative of interactions that could lead to mobbing (several males

actively defending a female with numerous male-male contests and frequent reversal from

challenging to defending roles by males) but did not escalate further. The two events both lasted

roughly 1 h and involved a different adult female and six and seven adult males. During the

incident involving six adult males, the female was noted to have minor injuries (approximately six

scratches along with several possible bite marks). In the incident involving seven adult males, no

obvious injuries to the female were noted at the time; however, 18 days later she was observed

with severe dorsal scratches and two abscesses. Whether these injuries resulted from the observed 

incident is unknown. 

Adult Male Interactions with Mother-Pup Pairs

On two separate occasions adult males were observed to separate mothers from their pups

and engage in successive mounting attempts with the former. During both incidents intense

splashing, rolling, and vocalizing were noted. Although pups remained nearby, each mother-pup

pair was separated from three to six minutes before the mother was able to repel the male and

reunite with her pup.

RESULTS

Subpopulation Abundance and Composition

The mean (±SD) of 28 censuses was 77.2 seals (±8.0) including pups, and 59.8 seals

(±7.2) excluding pups (Table 4.1). The total spring-summer subpopulation was 203 individuals,

170 excluding pups (Table 4.2). This number is a subset of the total identified during the calendar

year. The sex ratio for older (>17 years of age) and unknown aged adults was strongly skewed

toward males at ca. 3.2:1 (41 males: 13 females), whereas the ratio for younger adults (< 17 years

of age) was at unity at 1.0:1 (33 males: 33 females). The numbers of tagged known-age seals born

at Lisianski Island during the period from 1982 to 1998, and resighted at any location in 1999, are

summarized in Table 4.3.

Reproduction

A minimum of 33 pups were born at Lisianski Island in 1999: 27 were successfully

weaned, five died prior to weaning, and one disappeared and probably died (Table 4.4a). Nursing

periods and measurements of weaned pups are summarized in Table 4.4b. The birth rate,

measured as the number of pups born divided by the number of adult-sized females in the

subpopulation X 100 was 71.7% ((33/46) X 100). Two births were observed by researchers. A

minimum of 14 pup exchanges occurred among 16 nursing females; researchers observed 2 of

these incidents. One weaning incident was also observed.
42

Interatoll Movement

Interatoll movement was documented for 13 seals that completed a total of 20 movements

between Lisianski Island and either Laysan Island, Pearl and Hermes Atoll, or Midway Atoll

(Tables 4.5a and b).

Factors Affecting Survival

Attacks by large sharks, mounting attempts by male Hawaiian monk seals, entanglement

in marine debris, and other/unknown factors led to 34 life-threatening conditions, which resulted

in the confirmed deaths of six animals and the probable death of two seals (Table 4.6). One

mobbing incident was observed. No seals were known to have directly died following male

mounting incidents. However, three pups born to adult females recently injured by male

mounting, as evidenced by dorsal injuries, died. Two of these pups died within 7 days of birth,

and one perinatally. Seven seals were entangled: three escaped unaided and four were released by

observers.

In addition to the cases summarized in Table 4.6, several other cases are noteworthy. Two

prolonged adult male harassments of adult females were observed (described above). Male

harassment of weaned pups/juveniles was also observed 23 times; no fatalities occurred and 1

incident resulted in obvious, though minor, injury to the seal. A minimum of 13 other weaned

pups sustained minor dorsal scratches probably inflicted by other seals during unobserved

incidents. One yearling had recent entanglement scars indicating self-release from marine debris

sometime after July 1998. Two additional seals displayed healed large shark bite scars that were

not present on these animals in 1998; one scar was on a 2-year-old female’s right face and muzzle

area, the other scar was on an adult female with extensive scarring on the ventrum and posterior

laterals and partial amputation of the left hind flipper. One adult male visibly lost body mass

throughout the season and was deemed emaciated during the final month of study. A dead

unknown adult seal was found in October 1999; however, its identity could not be determined due

to advanced decomposition.

 

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife Service, Hawaiian Islands

National Wildlife Refuge staff. We thank the captain, officers, and crew of the NOAA ship

Townsend Cromwell for logistical assistance. 
43

TABLES

for Lisianski Island
44
45

Table 4.1.--Summary statistics for censuses (n = 28) of Hawaiian monk seals at Lisianski Island

 from March 31 to July 20, 1999.

Size/Sex Mean number of individuals Standard deviation

Adults 45.4 7.8

Male 26.1 5.2

Female 18.8 3.7

Unknown 0.6 0.9

Subadults 9.0 3.3

Male 4.6 2.2

Female 4.2 2.0

Unknown 0.1 0.3

Juveniles 5.5 2.4

Male 2.6 1.3

Female 2.8 1.6

Unknown 0.0 0.0

Pups 17.4 4.2

Male 10.4 2.6

Female 7.0 1.9

Unknown 0.0 0.2

Non-pup total 59.8 7.2

Grand total 77.2 8.0
46

Table 4.2.--Composition of the Hawaiian monk seal subpopulation at Lisianski Island during the 

 spring and summer of 1999. Includes all known parturient females and all pups born

 during the calendar year.

Number of seals

Size Male Female Unknown Total

Sex ratio

male:female

Adults 74 46 0 120 1.6:1

Subadults 13 12 0 25 1.1:1

Juveniles 12 13 0 25 0.9:1

Pups 21 11 1 33 1.9:1

Non-pup total 99 71 0 170 1.4:1

Grand total 120 82 1 203 1.5:1
47

Table 4.3.--Summary of tagged known-age seals born at Lisianski Island and resighted at any 

location in 1999.

Cohort year

Age

(years) Sex

Number originally

tagged

Number resighted

in 1999

1982 17 Male

Female

7

6

2

1

1983 16 Male

Female

6

18

2

7

1984 15 Male

Female

10

5

4

2

1985 14 Male

Female

5

9

2

1

1986 13 Male

Female

11

9

6

3

1987 12 Male

Female

12

6

1

1

1988 11 Male

Female

10

8

 5

6

1989 10 Male

Female

–

--

–

--

1990 9 Male

Female

8

9

4

3

1991 8 Male

Female

9

6

5

3

1992 7 Male

Female

13

8

6

4

1993 6 Male

Female

4

9

2

2

1994 5 Male

Female

 4

5

1

1

1995 4 Male

Female

 7

10

2

2

1996 3 Male

Female

 9

13

2

1

1997 2 Male

Female

 10

9

5

4

1998 1 Male

Female

 10

11

8

7
48

Table 4.4a.--Summary of Hawaiian monk seals born at Lisianski Island in 1999.

Event

Number of pups

Male Female Unknown Total

Born 21 11 1 33

Died/Probably died prior to weaning 5 0 1 6

Still nursing 0 0 0 0

Weaned 16 11 0 27

Tagged 16 11 0 27

Table 4.4b.--Summary of nursing periods and measurements of weaned pups at Lisianski Island

 in 1999. Nursing periods were calculated where both birth and weaning date ranges

 were < 4 days. All measurements were taken within 2 weeks after weaning. 

Nursing period (d) Axillary girth (cm)

Straight dorsal length

(cm)

Mean 37.9 105.8 124.2

Standard deviation 5.0 8.2 7.1

n 25 27 27
49

Table 4.5a.–Documented movement of Hawaiian monk seals to Lisianski Island from other

 locations in 1999, summarized by movements between two locations. One seal made

 more than one observed trip.

Original location Number, size, and sex class

Laysan Island 5 adult females

 2 subadult females

 1 juvenile male

 1 juvenile female

Pearl and Hermes Atoll 1 adult malea

 1 adult female 

a

 Seal was seen for one day only on Lisianski and was not seen again during the 1999 season at

any of the Northwestern Hawaiian Islands.

Table 4.5b.–Documented movement of Hawaiian monk seals from Lisianski Island to other

 locations in 1999, summarized by movements between two locations. No seals made

 more than one observed trip.

Destination Number, size, and sex class

Laysan Island 1 adult male

 5 adult females

Pearl and Hermes Atoll 2 adult females

Midway Atoll 1 subadult male
50

Table 4.6.--Factors affecting Hawaiian monk seal survival at Lisianski Island in 1999.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Adult Male

Female

2

3

2

3

0

0

0

0

Juvenile Male 

Female 

2

a

1

2

1

0

0

0

1

b

Mounting by Male

Adult Female 7c,d 7 0 0

Subadult Female 1 1 0 0

Weaned pup Male 2 2 0 0

Entanglement

Adult Male

Female

1

e

3

f 

0

0

0

0

0

0

Subadult Male 1

g 0 0 0

Weaned pup Male 2

h

0 0 0

Other/Unknown

Adult Female

Unknown

1

1

1

0

0

1

i

0

0

Weaned pup Male 1 1 0 0

Nursing pup Male

Unknown

5

1

0

0

5

j

0

0

1

k

a

Includes a seal with an extensive yet almost healed injury. Although not seen after the end of

March, it is unclear if this injury caused the seal’s disappearance. 

bSeal sustained a major shark bite injury, became thinner, had trouble moving, and was not seen

after 5/31/99. 

cAn observed mobbing involving one adult female and six adult males resulted in severe dorsal

injuries. This female was re-injured in an unobserved, unrelated event 33 days later.

dA seal was injured twice within 18 days. The injurieswere considered related, and counted once.

eSeal was released by observers.

fTwo seals freed themselves, one was released by observers.

gSeal entangled with eel cone on muzzle, released by observers.

hOne seal with eel cone on muzzle freed itself, one with a plastic ring on muzzle released by

observers.

iDecomposed carcass found during 1 day visit to the island in October.

jAll died within 7 days of age; three had mothers severely injured during male mounting events.

kPup of unknown sex disappeared 2 days after birth.
51

CHAPTER 5. THE HAWAIIAN MONK SEAL ON

PEARL AND HERMES ATOLL, 1999

Chad Yoshinaga, Michelle Wainstein, Kate Willis, and Andrew McClung 

53

Pearl and Hermes Atoll (lat. 27°55'N, long. 175°45'W) is one of the primary haulout and

pupping locations of the Hawaiian monk seal. This atoll is located ca. 1,900 km northwest of

Oahu in the Northwestern Hawaiian Islands and is part of the Hawaiian Islands National Wildlife

Refuge (Fig. 1.1). Pearl and Hermes is composed of four vegetated and three nonvegetated sand

islets enclosed in a fringing reef (Fig. 5.1).

RESEARCH

The National Marine Fisheries Service (NMFS) began research on Hawaiian monk seals at

Pearl and Hermes Atoll in 1982. In 1999, research was conducted by NMFS during May 25 - July

20. The perimeters of the four larger vegetated islets were divided into sectors using natural

landmarks. Research activities specific to this subpopulation in 1999 included large scale debris

removal from the fringing reef. 

Censuses and Patrols

Atoll censuses (n = 8) were conducted every fourth day, on average, from June 10 to July

16. Each atoll census began between 0910 and 1047 and ended between 1407 and 1636 Hawaii

standard time. All islets were censused on foot by one or two persons. In addition, incidental

patrols were conducted opportunistically to resight seals tagged in previous years and to identify

and bleach-mark all animals in the subpopulation.

Individual Identification

A total of 241 individuals (213 excluding pups) were identified by existing or applied tags,

scars, or natural markings. Twenty-five weaned pups were tagged with Temple Tags and passive

integrated transponder (PIT) tags. One weaned pup was tagged exclusively with Temple Tags.

Samples Collection

Forty scat and one spew samples were collected. Skin punches were collected from 26

seals during tagging. One skeletal sample was collected. In total, 449 items of potentially

entangling debris were inventoried and left at Pearl and Hermes Atoll for removal during a marine

debris cruise in October 1999.

Special Studies

Large Scale Marine Debris Removal from Reefs

A cooperative multi-agency coral reef cleanup was conducted at Pearl and Hermes Atoll in

October 1999 supported by the NOAA ship Townsend Cromwell and the USCG cutter Walnut. 

Personnel from 11 agencies removed debris to reduce these entanglement hazards to monk seals

and other marine life and document the extent of reef debris fouling. Debris collected and stored
54

on the beaches during the main 1999 field season were also removed. In total, 8,667 kg of debris

were recovered at Pearl and Hermes Atoll: 7,527 kg from the reef and 1,140 kg from the beaches. 

RESULTS

Subpopulation Abundance and Composition

The mean (±SD) of 8 atoll censuses was 98.6 seals (±11.5) including pups and 80.6 seals

(±12.7) excluding pups (Table 5.1). The total summer subpopulation was 234 individuals, 206

excluding pups (Table 5.2). This number is a subset of the total identified during the calendar

year. The numbers of tagged known-age seals born at Pearl and Hermes Atoll during the period

from 1983 to 1998 and resighted at any location in 1999 are summarized in Table 5.3.

Reproduction

At least 28 pups were born at Pearl and Hermes Atoll in 1999: 26 were successfully

weaned and two were still nursing at the end of the research period (Table 5.4). The birth rate,

measured as the number of pups born divided by the number of adult-sized females in the

subpopulation X 100, was 45.2% ((28/62) X 100). Nursing periods and measurements of weaned

pups are summarized in Table 5.4.

Interatoll Movement

Interatoll movement was documented for 20 seals that completed a total of 32 movements

between Pearl and Hermes Atoll and either Lisianski Island, Midway Atoll, or Kure Atoll (Tables

5.5a and b). 

Factors Affecting Survival

Entanglement in marine debris and other factors resulted in three life-threatening

conditions (Table 5.6). One adult and one subadult seal were disentangled from debris. A

weaned female pup was observed with two open abscesses on her back. In addition to the

incidents presented in Table 5.6, a carcass found on Little North islet, appeared to be an adultsized seal that had died since the previous field season .

ACKNOWLEDGMENTS

We thank the captain, officers, and crew of the NOAA Ship Townsend Cromwell. We

also acknowledge the support of the U.S. Fish and Wildlife Service, Hawaiian Island National

Wildlife Refuge staff.
55

TABLES

for Pearl and Hermes Reef
56
57

Table 5.1.--Summary statistics for atoll censuses (n = 8) of the Hawaiian monk seal at Pearl and

 Hermes Reef from June 10 to July 16, 1999.

Size/Sex Mean number of individuals Standard deviation

Adults 48.1 7.0

Male 17.3 5.3

Female 26.3 3.4

Unknown 4.6 2.8

Subadults 20.1 7.6

Male 8.0 4.0

Female 10.0 3.6

Unknown 2.1 2.1

Juveniles 11.5 0.9

Male 4.0 1.8

Female 7.1 1.8

Unknown 0.4 0.5

Pups 18.0 4.1

Male 5.8 2.3

Female 10.6 2.5

Unknown 1.6 0.5

Non-pup total 80.6 12.7

Grand total 98.6 11.5
58

Table 5.2.--Composition of the Hawaiian monk seal subpopulation at Pearl and Hermes Atoll

 during the spring and summer of 1999. Includes all known parturient females and

 pups born during the calendar year. 

Number of seals

Size Male Female Unknown Total

Sex ratio

male:female

Adults 64 62 0 126 1.0:1

Subadults 19 22 0 41 0.9:1

Juveniles 14 25 0 39 0.6:1

Pups 11 16 1 28 0.7:1

Non-pup total 97 109 0 206 0.9:1

Grand total 108 125 1 234 0.9:1
59

Table 5.3.--Summary of tagged known-age seals born at Pearl and Hermes Reef and resighted 

at any location in 1999.

Cohort year

Age

(years) Sex

Number originally

tagged

Number resighted 

in 1999

1983 16 Male

Female

8

2

4

1

1984 15 Male

Female

5

8

2

3

1985 14 Male

Female

9

6

3

3

1986 13 Male

Female

Unknown

10

7

1

2

2

0

1987 12 Male

Female

14

7

6

3

1988 11 Male

Female

12

6

9

4

1989 10 Male

Female

8

6

4

2

1990 9 Male

Female

5

1

2

0

1991 8 Male

Female

10

11

6

5

1992 7 Male

Female

13

10

10

8

1993 6 Male

Female

14

7

5

4

1994 5 Male

Female

--

--

–

--

1995 4 Male

Female

15

12

8

7

1996 3 Male

Female

11

12

3

6

1997 2 Male

Female

16

11

10

7

1998 1 Male

Female

8

21

5

16
60

Table 5.4a.--Summary of Hawaiian monk seals born at Pearl and Hermes Atoll in 1999.

Event

Number of pups

Male Female Unknown Total

Born 11 16 1 28

Died prior to weaning 0 0 0 0

Still nursing 0 1 1 2

Weaned 11 15 0 26

Tagged 11 15 0 26

Table 5.4b.--Summary of nursing periods and measurements of weaned pups at Pearl and Hermes

 Reef in 1999. All measurements were taken within 2 weeks after weaning. 

Nursing period (d) Axillary girth (cm)

Straight dorsal length

(cm)

Mean 36 105.7 126.1

Standard deviation -- 6.0 4.2

n 1 9 9
61

Table 5.5a.–Documented movement of Hawaiian monk seals to Pearl and Hermes Atoll from other

 locations in 1999, summarized by movements between two locations. No seals

 made more than one observed trip.

Original location Number, size, and sex class

Lisianski Island 2 adult females

Midway Atoll 2 adult males

7 adult females

1 subadult female

1 juvenile male

Kure Atoll 1 adult female

1 subadult male

1 subadult female

Table 5.5b.–Documented movement of Hawaiian monk seals from Pearl and Hermes Atoll to other

 locations in 1999, summarized by movements between two locations. One seal

 made more than one observed trip.

Destination Number, size, and sex class

Lisianski Island 1 adult male

1 adult female

Midway Atoll 3 adult males

4 adult females

2 subadult females

2 juvenile males

Kure Atoll 1 adult female

1 subadult male

1 subadult female
62

Table 5.6.--Factors affecting Hawaiian monk seal survival at Pearl and Hermes Atoll in 1999.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

(none observed)

Mounting by Males

(none observed)

Entanglement

Adult Male 1

a

0 0 0

Subadult Female 1

a

0 0 0

Other

Weaned pup Female 1 1 0 0

aSeal released by observers.
63

CHAPTER 6. THE HAWAIIAN MONK SEAL AT

MIDWAY ATOLL, 1999

Cynthia Vanderlip, Suzanne Canja, Wayne Sentman, and Bruce Casler

65

Midway Atoll (lat. 28°14'N, long. 177°22'W) is one of the primary haulout and pupping

locations of the endangered Hawaiian monk seal, although current population levels and pup

production are relatively low. This atoll is located ca. 2,100 km northwest of Oahu in the

Northwestern Hawaiian Islands (Fig. 1.1) and comprises a circular atoll reef approximately 9 km in

diameter, enclosing a lagoon and three permanent islets inside the southern part of the reef (Fig.

6.1). Eastern and Spit are uninhabited. Sand Island was the site of a U.S. Naval Air base from ca.

1939 until 1993. The U.S. Fish and Wildlife Service (USFWS) maintained an overlay refuge

(Midway Atoll National Wildlife Refuge) at the site since 1988, until full authority was transferred

to the USFWS in October 1996. In 1996, USFWS joined Midway Phoenix Corporation (MPC) in

a cooperative agreement. Through this agreement MPC maintains the infrastructure, and operates

the airport and harbor. Additionally, this agreement enables MPC to operate ecotourism and

recreational ventures. 

Beach counts of the Hawaiian monk seal at Midway Atoll averaged 56 animals in the late

1950s (Kenyon, 1972), but declined severely by the late 1960s; a single seal was observed during

an aerial survey in 1968 (Kenyon, 1972). Currently, recovery is underway because of immigration

from nearby Kure Atoll and Pearl and Hermes Atoll, and an increasing number of seals born on

Midway Atoll. Recovery of this subpopulation remains an important management goal (Gilmartin

and Antonelis, 1998).

RESEARCH

The National Marine Fisheries Service (NMFS) began limited monitoring of Hawaiian

monk seals at Midway Atoll in 1983. This effort was increased to year-round monitoring in 1997

by collaborating with researchers from Hawaii Wildlife Fund (HWF). In 1999, year-round

monitoring was continued by HWF researchers. In addition, monk seal/human related issues were

addressed by a NMFS biologist from May 9 to November 30, 1999, and NMFS conducted a health

assessment survey August 28-September 8, 1999. Perimeters of the three permanent islets were

divided into sectors using artificial or natural landmarks. Research activities specific to this

subpopulation in 1999 included (1) emergent reef surveys to determine haulout patterns on these

areas, (2) blood, tissue, and fecal sampling for a disease survey and foraging ecology studies, (3)

collection of reef fishes and invertebrates for fatty acid analysis, (4) assessment of nearshore reef

fish abundance (5) survey of the northern reef flats for lobster, eel, and octopus abundance, (6)

survey for, and removal of marine debris from the north and east reef flats and emergent reef areas,

and (7) monitoring human impacts on seals to quantify occurrence and potential effects on monk

seal habitat usage. 

Censuses and Patrols

Atoll censuses (n = 50) were conducted every seventh day, on average, from January 6 to

December 30. Each atoll census began between 0705 and 1425, and ended between 1418 and 1935

Hawaii standard time. All islets were censused on foot by one or two persons. Spit was
66

occasionally surveyed by boat on severe weather days. Patrols of Sand Island (n = 100), Eastern

(n = 95), or Spit (n = 87) were conducted on non-atoll census days during January 1-December 27. 

Individual Identification

A total of 86 individuals (71 excluding pups) were identified by existing or applied tags,

bleach marks, scars, or natural markings. Eleven pups weaned at Midway were tagged with

Temple tags and passive integrated transponder (PIT) tags. One prematurely weaned pup was not

tagged. In addition, a weaned female pup, born at an unknown location, was tagged with Temple

tags and PIT tags. During the health assessment study 8 seals were retagged with both Temple tags

and PIT tags (2 adult males, 4 adult females, 1 subadult female, and 1 juvenile male), 3 seals were

re-tagged with Temple tags (1 juvenile male, 1 juvenile female, and 1 weaned male pup), and 2

seals were re-tagged with PIT tags (1 adult male and 1 juvenile female).

Samples Collection

Skin punches were collected from 11 weaned pups during tagging. Eight spews, 240 scats,

3 placentas, and 23 shed molt samples were collected. Two necropsies were performed and tissue

samples were collected. Blood, fecal, and tissue samples were collected from 20 seals during the

health assessment survey. A total of 1,171 items of potentially entangling marine debris were

inventoried and either destroyed at Midway or stored on Midway for removal during a marine

debris cruise in October 1999. 

Special Studies

Health, Disease, and Foraging Ecology Studies

In August and September 1999, NMFS biologists collected blood and fecal samples and

blubber biopsies from 20 seals (9 adult and 6 immature seals, and 5 weaned pups) for ongoing

epidemiological and fatty acid diet studies. Assistance was provided by HWF. Although all 20

seals appeared healthy prior to capture, one adult male died during sedation. Thorough postmortem examination indicated that this seal had pulmonary and cardiac conditions which may have

predisposed him to mortality during capture. The purpose of this sampling was to obtain baseline

information to assess the health, disease status, and foraging ecology of the Hawaiian monk seal

population (Aguirre and Reif, 1998). 

Emergent Reef Surveys

Patrols were conducted two times per week on average along the emergent reef areas of the

North Reef (n = 94), and East Reef (n = 93), and once per week along the Southwest Reef (n = 55)

from January 8 to November 21, 1999. Two people using kayaks and a motorboat surveyed the

reefs for seals and turtles. On 21 occasions, all three emergent reef areas were surveyed within one

day of atoll counts to provide an estimate of atoll-wide beach/emergent reef counts.
67

Prey Availability

In July, the Honolulu Laboratory, NMFS, conducted diving transects around Midway Atoll

to estimate densities of reef fishes. These surveys replicated those surveys conducted at Midway

Atoll during 1980-83, 1992, 1995-98 (see DeMartini et al., 1993). In 1998 and 1999 this study was

expanded to assess fish abundance at deeper sites (50-60 m). The results of this ongoing research

will be reported elsewhere.

From July 30 to November 21, 119 samples of invertebrates and teleost fish were collected

in Midway Atoll waters for analysis of fatty acid in potential monk seal prey. Lobster traps were

set both inside and outside the lagoon to collect invertebrates and some fish species. Most fish

were collected inside the lagoon around shallow reefs by skin divers using Hawaiian slings. The

lobster specimens (n = 37) were the primary focus in the prey sampling. HWF assisted NMFS

personnel with the collection of the specimens and Midway Phoenix Corporation donated the use

of their lobster traps for this project.

Reef Surveys for Eels, Lobsters, and Octopus at Midway Atoll

A quantitative diving survey for eels, lobsters, and octopus was conducted on the north and

southwest reef flats of Midway’s lagoon from June 16 to September 15. This study was a

collaborative effort between USFWS and NMFS.

Large Scale Marine Debris Removal from Reefs

From May to November, 9,363 kg of marine debris were removed from the atoll reef and

associated reef flats. Diving transect surveys were conducted from the north end of the atoll reef

working east, along established monk seal reef patrol sectors. Transect lines, ca. 0.4 km long, were

surveyed on reef flats perpendicular to the reef crest (emergent reef). Crews worked 2-3 days a

week, weather permitting. In addition, 2,270 kg of debris were collected along the shores of the

atoll’s three islets. This study was a collaborative effort between USFWS, NMFS, and HWF. The

NOAA ship Townsend Cromwell and the USCG cutter Walnut recovered most of the debris stored

at Midway as part of a cooperative multi-agency reef cleanup in October 1999.

Noteworthy Events

Beach Monitoring and Public Education

From May to November1999, Sand Island beaches and trails were monitored for

approximately 10 h/week. Monk seal natural history was shared opportunistically with visitors and

residents. On five occasions NMFS observer intervention prevented the probable disturbance of

resting monk seals; three involved persons violating refuge rules in the presence of mother/pup

pairs. Other actions taken to mitigate disturbance to seals included trail maintenance, planting

native vegetation at trail overlooks to create natural blinds, identification of problem areas, and

delineating sites (with yellow tape) where seals were resting or molting in areas of public access. 

Fourteen informational lectures were presented to residents and visitors, covering monk seal

natural history, NMFS recovery efforts, and the reasons for refuge rules governing seal viewing
68

and beach closures. These lectures were eventually incorporated into USFWS’s weekly briefing

for guests. 

RESULTS

Subpopulation Abundance and Composition

The mean (+SD) of 50 atoll censuses was 23.5 seals (+7.4) including pups, and 18.7 seals

(+7.1) excluding pups (Table 6.1). The total spring-summer subpopulation was 68 seals, 55

excluding pups (Table 6.2). This number is a subset of the total identified in the calendar year. 

The numbers of tagged known-age seals born at Midway Atoll during the period from 1988 to

1998, and resighted at any location in 1999, are summarized in Table 6.3.

Reproduction

A minimum of 12 pups were born at Midway Atoll in 1999, and all successfully weaned

(Table 6.4a). The birth rate, measured as the number of pups born divided by the number of adultsized females in the subpopulation X 100 was 60.0% ((12/20) X 100). A minimum of one pup

exchange occurred between nursing females, resulting in one prematurely weaned pup. Nursing

periods and measurements of weaned pups are summarized in Table 6.4b.

Interatoll Movement

Interatoll movement was documented for 30 seals that completed a total of 49 movements

between Midway Atoll and either Lisianski Island, Pearl and Hermes Atoll, Kure Atoll, or an

unknown location (Tables 6.5a and b).

Factors Affecting Survival

Attacks by sharks, entanglement in marine debris, and other/unknown causes led to 11 lifethreatening conditions, which resulted in the confirmed deaths of two animals and the probable

death of an additional seal (Table 6.6). One subadult female was found dead of unknown causes,

and an adult male seal died while under restraint during the health assessment survey. One pup

disappeared after he was prematurely weaned due to a pup exchange. Three seals were entangled

in marine debris: a juvenile male escaped unaided, and two others (an adult female and weaned

male pup) were released by observers. In addition, one aborted fetus was found on Eastern islet in

November. 

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife Service, Oceanic Society, and

Midway Phoenix Corporation. Special thanks are extended to Robert Shallenberger, Refuge

Manager; Nancy Hoffman, Refuge Biologist; Bob Wilson, Midway Harbor Master and the Midway

Harbor crew. We also thank the officers and crew of the NOAA ship Townsend Cromwell for

logistical assistance. We are very grateful to Hays A. McLellan and the Pacific Marine Life

Foundation for the funding support given to HWF for monk seal research at Midway. We would
69

like to honor the memory of Hays A. McLellan and his dedication to the Midway Atoll Hawaiian

monk seal recovery effort. 
70
71

TABLES

for Midway Atoll
72
73

Table 6.1.--Summary statistics for atoll censuses (n = 50) of Hawaiian monk seals at Midway

 Atoll from January 6 to December 30, 1999.

Size/Sex Mean number of individuals Standard deviation

Adults 9.6 3.7

Male 3.7 1.6

Female 5.6 3.0

Unknown 0.3 0.5

Subadults 2.2 1.6

Male 0.6 0.7

Female 1.5 1.1

Unknown 0.1 0.4

Juveniles 7.0 2.8

Male 3.7 1.7

Female 3.1 1.5

Unknown 0.2 0.4

Pups 4.7 2.9

Male 2.9 1.8

Female 1.7 1.5

Unknown 0.1 0.3

Non-pup total 18.7 7.1

Grand total 23.5 7.4
74

Table 6.2.--Composition of the Hawaiian monk seal subpopulation at Midway Atoll during the

 spring and summer of 1999. Includes all known parturient females and pups born 

 during the calendar year.

Number of seals

Size Male Female Total

Sex ratio

male:female

Adults 13 20 33 0.7:1

Subadults 1 5 6 0.2:1

Juveniles 9 7 16 1.3:1

Pups 8 5

a

13a

 1.6:1

Non-pup total 23 32 55 0.7:1

Grand total 31 37 68 0.8:1

a

Includes a weaned female pup born at an unknown location that arrived on May 29 and was

tagged at Midway Atoll. This pup may have been born at Pearl and Hermes Atoll or Kure Atoll.
75

Table 6.3.--Summary of tagged known-age seals born at Midway Atoll and resighted at any

location in 1999.

Cohort year

Age

(years) Sex

Number

originally tagged

Number resighted

in 1999

1988 11 Male

Female

0

1

NA

1

1989 10 Male

Female

0

0

NA

NA

1990 9 Male

Female

0

0

NA

NA

1991 8 Male

Female

1

1

1

1

1992 7 Male

Female

0

1

NA

1

1993 6 Male

Female

1

0

0

NA

1994 5 Male

Female

0

0

NA

NA

1995 4 Male

Female

Unknown

1

6

1

0

1

0

1996 3 Male

Female

1

4

1

1

1997 2 Male

Female

3

6

2

5

1998 1 Male

Female

8

2

5

2
76

Table 6.4a.--Summary of Hawaiian monk seals born at Midway Atoll in 1999.

Event

Number of pups

Male Female Total

Born 8 4 12

Died prior to weaning 0 0 0

Weaned 8 4 12

Tagged 7

a

4 11a

aA prematurely weaned male pup was not tagged. This pup later disappeared.

.

Table 6.4b.--Summary of nursing periods and measurements of weaned pups at Midway Atoll in

 1999. Nursing periods were calculated where both birth and weaning date ranges

 were < 4 d. All measurements were taken within 2 weeks after weaning. 

Nursing period (d) Axillary girth (cm)

Straight dorsal length

(cm)

Mean 36.7 110.0 127.0

Standard deviation 6.4 7.6 7.0

n 12 11 11
77

Table 6.5a.–Documented movement of Hawaiian monk seals to Midway Atoll from other locations

 in 1999, summarized by movements between two locations. Three seals made more

 than one observed trip.

Destination Number, size, and sex class

Lisianski Island 1 subadult male

Pearl and Hermes Atoll 3 adult males

4 adult females

2 subadult females

2 juvenile males

Kure Atoll 2 adult males

8 adult females

3 subadult males

3 weaned female pups

Unknown location 1 weaned female pup

Table 6.5b.–Documented movement of Hawaiian monk seals from Midway Atoll to other locations 

 in 1999, summarized by movements between two locations. No seals made more than

 one observed trip.

Destination Number, size, and sex class

Pearl and Hermes Atoll 2 adult males

7 adult females

1 subadult female

1 juvenile male

Kure Atoll 2 adult males

5 adult females

1 subadult male

1 weaned female pup
78

Table 6.6.--Factors affecting Hawaiian monk seal survival at Midway Atoll in 1999.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Adult Female 2 2 0 0

Subadult Female 1 1 0 0

Juvenile Male 1 1 0 0

Mounting by Males

(none observed)

Entanglement

Adult Female 1

a

0 0 0

Juvenile Male 1

b

0 0 0

Weaned pup Male 1

c

0 0 0

Other/Unknown

Adult Male

Female

1

d

1

 

0

1

1

0

0

0

Weaned pup Male 1

e

0 0 1

Subadult Female 1

f

0 1 0

aSeal released by researchers.

 bSeal freed itself.

cSeal released by researchers. 

dSeal died during restraint for health assessment study.

ePup weaned prematurely due to an exchange. Condition deteriorated to thin over a 21-day period

postweaning before pup disappeared. 

fSeal was found dead, but the cause was not determined.

 
79

CHAPTER 7. THE HAWAIIAN MONK SEAL AT

KURE ATOLL, 1999

Irene T. Kinan, David V. Gummeson, and R. Wayne Sentman

81

Kure Atoll (lat. 28°25'N, long. 178°10'W) is one of the primary haulout and pupping

locations of the Hawaiian monk seal. The atoll is located ca. 2,300 km northwest of Oahu in the

Northwestern Hawaiian Islands (Fig. 1.1) and is a seabird sanctuary of the State of Hawaii. The

atoll consists of a circular fringing reef approximately 9 km in diameter, the enclosed lagoon, one

permanent vegetated island (Green Island), two sand islets (Sand and Shark), and an ephemerally

emergent area known locally as Stark Reef (Fig. 7.1). From 1960 to 1992, Green Island was the

site of a U.S. Coast Guard (USCG) LORAN station, staffed by 20-30 USCG personnel. In July

1992, this station was closed and vacated by the USCG, leaving the atoll uninhabited. In 1993, the

USCG completed the removal of most of the infrastructure on Green Island. 

The Kure Atoll subpopulation of Hawaiian monk seals has been increasing in recent years

due, apparently in part, to a reduction of human disturbance and to two capture and release

programs designed to increase recruitment of females. The Head Start Project (1981 to 1991)

involved the capture and protection of weaned female pups from Kure Atoll during the transition

phase from weaning to independent feeding. The Rehabilitation Project (1984-91, 1993-95)

involved the capture of undersized weaned female pups from French Frigate Shoals, their

rehabilitation on Oahu, and subsequent transport of these seals to Kure Atoll for release. 

RESEARCH

National Marine Fisheries Service (NMFS) began research on the Hawaiian monk seal at

Kure Atoll in 1981. In 1999, research was conducted by NMFS from May 24 to July 23, and July

27 to August 2. The perimeter of Green Island was divided into eight sectors using artificial or

natural landmarks. Research objectives specific to this subpopulation in 1999 included (1)

evaluating the success of past management efforts and (2) assessing entanglement risks and other

negative impacts following the Paradise Queen II’s grounding at Kure Atoll on October 16, 1998.

Censuses and Patrols

Atoll censuses (n = 10) were conducted every fifth day on average, from June 4 to July 19. 

Each census began between 1237 and 1345 and ended between 1435 and 1600 Hawaii standard

time. All islets were censused on foot by one or two persons. Stark Reef was not emergent during

the 1999 field season. 

Patrols were conducted on non-atoll census days to identify seals and monitor locations

used by parturient females. In total, 31 patrols of Green Island and 5 patrols of Sand islet were

conducted. Patrols were not conducted the day before atoll censuses. 

Individual Identification

A total of 127 individuals (106, excluding pups) were identified by existing or applied tags,

bleach marks, scars, or natural markings. All weaned pups (n = 21) were tagged with Temple

Tags, and passive integrated transponder (PIT) tags. One subadult male seal was re-tagged.
82

Samples Collection

Twenty-seven scat and one spew samples were collected. Skin punches were collected

from 21 seals during tagging. Samples from four placentas were also collected. In total, 180 items

of potentially entangling marine debris were inventoried; 2 items removed from seals were

collected and the remainder was destroyed. Two large (estimated >500 lbs) conglomerates (one net

and one line) remain buried on Green Island. Emergent parts of both conglomerates were burned

in situ to minimize their entanglement hazard.

 Noteworthy Events

Impacts of Paradise Queen II Grounding

On October 16, 1998 the Paradise Queen II, a lobster fishing vessel, ran aground on the

eastern edge of Kure Atoll. In 1999, large portions of the hull and wheel house remained on the

reef, smaller structural pieces had washed ashore, and a large portion of the main deck had come to

rest on the west side of Green Island in sector 1. Monk seals occasionally haul out on the deck. In

addition, the beaches of the east side of Green Island were littered with pieces of foam insulation

from the interior hull of the boat. This non-biodegradable insulation is easily blown about by the

wind.

During clean-up effort soon after Paradise Queen II ran aground, accessible hazardous

material and lobster traps were removed from the marine environment. Lead was removed from

approximately 350 recovered traps, and the traps were stacked at the northeast end of the runway

on Green Island. Since that time, additional lobster traps have continued to wash ashore. During

1999, approximately 100 traps were removed from Green Island beaches. In late July, the crew of

the NOAA ship Townsend Cromwell removed these newly recovered traps and approximately half

of the original lobster traps. An underwater reef survey conducted July 23 by NMFS personnel

noted that traps were still in the water. 

In addition to the traps above, a very large line conglomerate washed ashore at the

southeast point of Green Island at the border of sectors 5 and 6. Based on other line debris

recovered with lobster traps from other sectors of the islet, it is evident that this line conglomerate

is debris from the Paradise Queen I1. Although this conglomerate was partially burned in an effort

to minimize its entanglement hazard, only a small portion was consumed, and the rest remains

onshore. 

Photographic Observation and Seal Disentanglement

From July 27 to August 2, a NMFS observer accompanied a British Broadcasting

Corporation (BBC) film crew to Kure Atoll. During this trip, an entangled weaned female pup was 

released from a floating 600-lb conglomerate of marine debris composed of fishing net and line. 

An additional pup was also observed swimming in this debris. After the entangled pup was freed,

the net was removed from the reef. The entire episode was documented on film by the BBC crew. 
83

RESULTS

Subpopulation Abundance and Composition

The mean (±SD) of 10 atoll censuses was 53.3 seals (±9.7) including pups, and 42.0 seals

(±8.7) excluding pups (Table 7.1). The total spring-summer subpopulation was 124 individuals,

103 excluding pups (Table 7.2). The numbers of tagged known-age seals born at Kure Atoll

during the period from 1981 to 1998, and resighted at any location in 1999, are summarized in

Table 7.3.

Reproduction

At least 21 pups were born at Kure Atoll in 1999, and all successfully weaned (Table 7.4a). 

Nursing periods and measurements of weaned pups are summarized in Table 7.4b.) The birth rate,

measured as the number of pups born divided by the number of adult-sized females in the

subpopulation X 100 was 58.3% ((21/36) X 100). Eight of the 11 identified parturient females

(73%) had either been temporarily maintained as pups in the Kure Atoll Head Start Project or

rehabilitated from FFS via the Head Start enclosure.

Interatoll Movement

Interatoll movement was documented for 19 seals that completed a total of 31 movements

between Kure Atoll and either Pearl and Hermes or Midway Atolls (Table 7.5a and b).

Factors Affecting Survival

Entanglement in marine debris resulted in two life-threatening conditions (Table 7.6). One

weaned pup was observed with a plastic ring stuck on its muzzle. This weaned pup was

subsequently restrained and the ring removed and collected. A second weaned pup was discovered

entangled and then released from a large trawl net caught on the emergent reef northeast of Green

Island.

ACKNOWLEDGMENTS

We acknowledge the support of the State of Hawaii, Department of Land and Natural

Resources and Division of Forestry and Wildlife. We thank the captain and crew of the NOAA

ship Townsend Cromwell for logistical support, for transport to and from Kure Atoll, and for their

hard work in removing derelict lobster traps. 
84
85

TABLES

for Kure Atoll
86
87

Table 7.1.--Summary statistics for atoll censuses (n = 10) of Hawaiian monk seals at Kure Atoll

from June 4 to July 19, 1999.

Size/Sex Mean number of individuals Standard deviation

Adults 25.3 6.5

Male 10.0 2.9

Female 14.6 3.9

Unknown 0.7 1.1

Subadults 10.0 1.9

Male 7.5 1.4

Female 2.3 1.6

Unknown 0.2 0.4

Juveniles 6.7 2.6

Male 4.5 1.8

Female 2.1 1.1

Unknown 0.1 0.3

Pups 11.3 2.3

Male 4.9 1.2

Female 6.3 1.3

Unknown 0.1 0.3

Non-pup total 42.0 8.7

Grand total 53.3 9.7
88

Table 7.2.--Composition of the Hawaiian monk seal subpopulation at Kure Atoll during the spring

and summer of 1999. Includes all known parturient females and pups born during the

calendar year.

Number of seals

Size Male Female Total

Sex ratio

male:female

Adults 28 36 64 0.8:1

Subadults 14 8 22 1.8:1

Juveniles 10 7 17 1.4:1

Pups 8 13 21 0.6:1

Non-pup total 52 51 103 1.0:1

Grand total 60 64 124 0.9:1
89

Table 7.3.--Summary of tagged known-age seals born at Kure Atoll and resighted at any 

location in 1999.

Cohort year

Age

(years) Sex

Numb er originally

tagged

Number resighted

in 1999

1981 18 Male

Female

3

5

1

1

1982 17 Male

Female

1

3

0

3

1983 16 Male

Female

4

0

3

NA

1984 15 Male

Female

4

2

1

2

1985 14 Male

Female

2

3

1

2

1986 13 Male

Female

1

0

0

NA

1987 12 Male

Female

1

3

1

3

a

1988 11 Male

Female

2

5

2

2

1989 10 Male

Female

5

4

1

1

1990 9 Male

Female

3

3

0

1

1991 8 Male

Female

7

6

4

3

a

1992 7 Male

Female

5

8

3

5

1993 6 Male

Female

9

4

6

2

1994 5 Male

Female

3

0

0

NA

1995 4 Male

Female

6

5

4

3

1996 3 Male

Female

10

6

4

0

1997 2 Male

Female

9

7

2

4

1998 1 Male

Female

16

6

10

4

a Cohort survivors include se als removed from K ure Atoll for rehabilitation. These seals (n = 2) were released at Kure

or Mid way Atoll.
90

Table 7.4a.--Summary of Hawaiian monk seals born at Kure Atoll in 1999.

Event

Number of pups

Male Female Total

Born 8 13 21

Died prior to weaning 0 0 0

Weaned 8 13 21

Tagged 8 13 21

Table 7.4b.--Summary of nursing periods and measurements of weaned pups at Kure Atoll in

1999. Nursing periods were calculated where both birth and weaning date ranges were

< 4 d. All measurements were taken within 2 weeks after weaning. 

Nursing period (d) Axillary girth (cm)

Straight dorsal length

(cm)

Mean 36.0 110.5 128.4

Standard deviation 3.5 8.0 6.0

n 5 11 11
91

Table 7.5a.–Documented movement of Hawaiian monk seals to Kure Atoll from other locations in

 1999, summarized by movements between two locations. No seals made more than 

 one observed trip.

Original location Number, size, and sex class

Midway Atoll 2 adult males

5 adult females

1 subadult male

1 weaned female pup

Pearl and Hermes Atoll 1 adult female

1 subadult male

1 subadult female

Table 7.5b.–Documented movement of Hawaiian monk seals from Kure Atoll to other locations in

 1999, summarized by movements between two locations. Two seals made more than 

 one observed trip.

Destination Number, size, and sex class

Pearl and Hermes Atoll 1 adult female

1 subadult male

1 subadult female

Midway Atoll 2 adult males

8 adult females

3 subadult males

3 weaned female pups
92

Table 7.6.--Factors affecting Hawaiian monk seal survival at Kure Atoll in 1999.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

(none observed)

Mounting by Males

(none observed)

Entanglement

Weaned pup Male

Female

1

a

1

b

0

0

0

0

0

0

aSeal had a plastic circular object stuck on his muzzle, released by observers.

bSeal was discovered entangled in floating net/line conglomerate and released by observers during

 the BBC film crew visit, after the end of the main field season. Another pup was swimming in the 

 debris but not entangled.
93

CHAPTER 8. THE HAWAIIAN MONK SEAL ON

NIHOA AND NECKER ISLANDS, 1999

Bud A. Antonelis, Jason D. Baker, Brenda L. Becker, 

Mitchell P. Craig, and Melissa Shaw

95

Nihoa Island (lat. 23°04'N, long. 161°55'W) and Necker Island (lat. 23°36'N, long.

164°42'W) are located ca. 450 and 750 km, respectively, northwest of Oahu in the Northwestern

Hawaiian Islands (Fig. 1.1). These islands lie within the Hawaiian Islands National Wildlife

Refuge. Although endangered Hawaiian monk seals use these islands, their numbers are limited by

lack of haulout area.

RESEARCH

In 1999, the National Marine Fisheries Service collected data at Nihoa Island on July 31,

and at Necker Island on May 17 and July 30. The perimeters of Nihoa and Necker Islands were

divided into 3 and 10 sectors, respectively, using natural landmarks (Fig. 8.1). In 1999, research

objectives specific to the Nihoa and Necker Islands included assessment of pup production and the

extent of migration between French Frigate Shoals and these locations.

Censuses and Patrols

A beach count was conducted on Nihoa Island by two observers on July 31, beginning at 

1402 Hawaii standard time and continuing for approximately 1 h. A simultaneous boat survey of

the shoreline was also conducted.

Two beach counts were conducted on Necker Island, on May 17 and July 30, by three and

two observers, respectively. Censuses began between 0930 and 1000 Hawaii standard time and

continued for 4 or 5 h. A simultaneous boat survey was also conducted on July 30. 

Individual Identification

On Nihoa Island, two seals were identified by applied tags; two weaned pups (a male and a

female) were tagged with Temple tags and with passive integrated transponder (PIT) tags.

On Necker Island, four seals (three males, one female) were identified by existing tags

applied at French Frigate Shoals, including an 8-yr-old female, a 10-yr-old male, a 12-yr-old male,

and a 15-yr-old male. Two of these animals, both males, had last been seen at French Frigate

Shoals in 1995 and 1997, respectively. The other two seals (a male and a female) were last seen at

Necker Island in 1993. Two additional adult seals (a male and a female) were observed with

yellow tags applied at French Frigate Shoals, but these seals were not identified.

Samples Collection

On Nihoa Island, skin punches were collected from two weaned pups during tagging. No

samples were collected at Necker Island. 
96

RESULTS

Subpopulation Abundance and Composition

The census total for one count conducted on Nihoa Island was 31 seals (26 excluding

pups). Because of limited effort, the composition of the spring-summer subpopulation was not

determined. 

The census totals for two counts conducted on Necker Island were 9 seals (no pups

observed) on 17 May and 30 seals (29 excluding pups) on 30 July. The mean of the two counts is

19.5 (+ 14.8 SD). Because of limited effort, the composition of the spring-summer subpopulation

was not determined.

Reproduction

At least five pups were born at Nihoa Island in 1999; three were successfully weaned (two

females and one male), and two were still nursing (one male and one of unknown sex). One

weaned male pup was seen at Necker Island in 1999.

Interatoll Movement

Interatoll movement was not documented for seals observed at Nihoa Island. Interatoll

movement was documented for two seals that completed a total of three movements between

Necker Island and French Frigate Shoals (Tables 8.1a and b). 

Factors Affecting Survival

Factors affecting survival were not observed on Nihoa or Necker Islands in 1999. 

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife Service, Hawaiian Island

National Wildlife Refuge staff, and the captain, officers, and crew of the NOAA ship Townsend

Cromwell for logistical assistance.
97

TABLES

for Necker Island
98
99

Table 8.1a.--Documented movement of Hawaiian monk seals to Necker Island from other locations 

 in 1999, summarized by movements between two locations. No seals made more than

 one observed trip.

Original location Number, size, and sex class

French Frigate Shoals 2 adult males

Table 8.1b.--Documented movement of Hawaiian monk seals from Necker Island to other

 locations in 1999, summarized by movements between two locations. No seals made

 more than one observed trip.

Destination Number, size, and sex class

French Frigate Shoals 1 adult male
100
101

REFERENCES
102
103

Aguirre, A. A. And J .S. Reif.

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Alcorn, D. J.

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Boness, D. J.

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Island. U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFC-253, 14

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Gilmartin, W. G. and T. Gerrodette.

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Johanos, T. C. and Kam, A. K. H.

1986. The Hawaiian monk seal on Lisianski Island: 1983. U.S. Dep. Commer., NOAA

Tech. Memo., NOAA-TM-NMFS-SWFC-58, 37 p.

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1972. Man versus the monk seal. J. of Mammal. 53(4):687-696.

Lombard, K. B., B. L. Becker, M. P. Craig, G. C. Spencer, and K. Hague-Bechard.

1994. The Hawaiian monk seal on Laysan Island, 1990. U.S. Dep. Commer., NOAA

Tech. Memo. NOAA-TM-NMFS-SWFSC-206, 16 p.

Stone, H. S.

1984. Hawaiian monk seal population research, Lisianski Island, 1982. U.S. Dep.

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Winchell, J. 

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104
105

APPENDIXES
106
107

Appendix A.--Reports summarizing annual field research on the Hawaiian monk seal by the

National Marine Fisheries Service and collaborating scientists.

All islands

Johanos, T. C., and J. D. Baker (Eds.).

2000. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1998. U.S. Dep.

Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-292, 125 p.

Johanos, T. C., and T. J. Ragen (Eds.).

1999. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1997. U.S. Dep.

Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-262, 131 p.

Johanos, T. C., and T. J. Ragen (Eds.).

1999. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1996. U.S. Dep.

Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-259, 134 p.

Johanos, T. C., and T. J. Ragen (Eds.).

1997. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1995. U.S. Dep.

Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-241, 121 p.

Johanos, T. C., and T. J. Ragen (Eds.).

1996. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1993. U.S. Dep.

Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-227, 141 p.

Johanos, T. C., and T. J. Ragen (Eds.).

1996. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1994. U.S. Dep.

Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-229, 111 p.

Johanos, T. C., L. M. Hiruki, and T. J. Ragen (Eds.).

1995. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1992. U.S. Dep.

Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-216, 128 p.

French Frigate Shoals

Craig, M. P., J. L. Megyesi, C. S. Hall, J. L. Glueck, L. P. Laniawe, E. A. Delaney, S. S. Keefer,

 M. A. McDermond, M. S. Schulz, G. L. Nakai, B. L. Becker, L. M. Hiruki, and R. J. Morrow.

1994. The Hawaiian monk seal at French Frigate Shoals, 1990-91. U.S. Dep. Commer.,

NOAA Tech. Memo., NOAA-TM-NMFS-SWFSC-210, 70 p.

Craig, M. P., D. J. Alcorn, R. G. Forsyth, T. Gerrodette, M. A. Brown, B. K. Choy, L. Dean, L. M.

 Dennlinger, L. E. Gill, S. S. Keefer, M. M. Lee, J. S. Lennox, C. R. Lorence, G. L. Nakai, and 

 K. R. Niethammer.

1992. The Hawaiian monk seal at French Frigate Shoals, 1988-89. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-178, 83 p.
Appendix A.--Continued.

108

Eliason, J. J., J. R. Henderson, and M. A. Webber.

1993. Hawaiian monk seal observations at French Frigate Shoals, 1985. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-187, 46 p.

Eliason, J. J., and J. R. Henderson.

1992. Hawaiian monk seal observations at French Frigate Shoals, 1984. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-177, 61 p.

Fairaizl, G. W.

1984. Intra-atoll resighting of the Hawaiian monk seal, Monachus schauinslandi, at French

Frigate Shoals, 1 January 1983-31 August 1983. Southwest Fish. Cent. Honolulu Lab.,

Natl. Mar. Fish Serv., NOAA, Honolulu, HI 96822-2396. Southwest Fish. Cent. Admin.

Rep. H-84-5C, 27 p.

Johnson, P. A., and B. W. Johnson.

1984. Hawaiian monk seal observations on French Frigate Shoals, 1980. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-50, 47 p.

Laysan Island

Alcorn, D.

1984. The Hawaiian monk seal on Laysan Island: 1982. U.S. Dep. Commer., NOAA

Tech. Memo. NOAA-TM-NMFS-SWFC-42, 37 p.

Alcorn, D. J., and E. K. Buelna.

1989. The Hawaiian monk seal on Laysan Island, 1983. U.S. Dep. Commer., NOAA

Tech. Memo. NOAA-TM-NMFS-SWFC-124, 46 p.

Alcorn, D. J., and R. L. Westlake.

1993. The Hawaiian monk seal on Laysan Island, 1986. U.S. Dep. Commer., NOAA

Tech. Memo. NOAA-TM-NMFS-SWFSC-191, 25 p.

Becker, B. L., P. A. Ching, L. M. Hiruki, and S. A. Zur.

1994. The Hawaiian monk seal on Laysan Island, 1987 and 1989. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-213, 20 p.

Becker, B. L., R. J. Morrow, and J. K. Leialoha.

1989. Censuses and interatoll movements of the Hawaiian monk seal on Laysan Island,

1985. U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-135, 25 p.

Becker, B. L., K. E. O'Brien, K. B. Lombard, and L. P. Laniawe.

1995. The Hawaiian monk seal on Laysan Island, 1991. U.S. Dep. Commer., NOAA

Tech. Memo. NOAA-TM-NMFS-SWFSC-214, 16 p.
Appendix A.--Continued.

109

Johanos, T. C., and S. L. Austin.

1988. Hawaiian monk seal population structure, reproduction, and survival on Laysan

Island, 1985. U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TMNMFS-SWFC-118, 38 p.

Johanos, T. C., B. L. Becker, M. A. Brown, B. K. Choy, L. M. Hiruki, R. E. Brainard, 

 and R. L. Westlake

1990. The Hawaiian monk seal on Laysan Island, 1988. U.S.Dep. Commer., NOAA Tech.

Memo. NOAA-TM-NMFS-SWFSC-151, 24 p.

Johanos, T. C., A. K. H. Kam, and R. G. Forsyth.

1987. The Hawaiian monk seal on Laysan Island: 1984. U.S. Dep. Commer., NOAA

Tech. Memo. NOAA-TM-NMFS-SWFC-70, 38 p.

Johnson, B. W., and P. A. Johnson.

1984. Observations of the Hawaiian monk seal on Laysan Island from 1977 through 1980. 

U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-49, 65 p.

Lombard, K. B., B. L. Becker, M. P. Craig, G. C. Spencer, and K. Hague-Bechard.

1994. The Hawaiian monk seal on Laysan Island, 1990. U.S. Dep. Commer., NOAA

Tech. Memo. NOAA-TM-NMFS-SWFSC-206, 16 p.

Lisianski Island

Alcorn, D. J., R. G. Forsyth, and R. L. Westlake.

1988. Hawaiian monk seal research on Lisianski Island, 1984 and 1985. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-120, 22 p. 

Johanos, T. C., and J. R. Henderson.

1986. Hawaiian monk seal reproduction and injuries on Lisianski Island, l982. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-64, 7 p.

Johanos, T. C., and A. K. H. Kam.

1986. The Hawaiian monk seal on Lisianski Island: 1983. U.S. Dep. Commer., NOAA

Tech. Memo. NOAA-TM-NMFS-SWFC-58, 37 p.

Johanos, T. C., and R. P. Withrow.

1988. Hawaiian monk seal and green turtle research on Lisianski Island, 1987. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-121, 18 p.

Lee, M. M., L. K. Timme, R. Van Toorenburg, and B. L. Becker.

1993. The Hawaiian monk seal on Lisianski Island, 1988 and 1990. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-179, 33 p.
Appendix A.--Continued.

110

Stone, H. S.

1984. Hawaiian monk seal population research, Lisianski Island, 1982. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-47, 33 p. 

Westlake, R. L., and P. J. Siepmann.

1988. Hawaiian monk seal and green turtle research on Lisianski Island, 1986. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-119, 18 p.

Pearl and Hermes Atoll

Choy, B. K., and L. M. Hiruki.

1992. The Hawaiian monk seal and green turtle on Pearl and Hermes Reef, 1988. U.S.

Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-175, 18 p. 

Finn, M. A., J. R. Henderson, B. L. Becker, and T. J. Ragen.

1993. The Hawaiian monk seal and green turtle at Pearl and Hermes Reef, 1990 and 1991. 

U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-182, 29 p.

Forsyth, R. G., D. J. Alcorn, T. Gerrodette, and W. G. Gilmartin.

1988. The Hawaiian monk seal and green turtle on Pearl and Hermes Reef, 1986. U.S.

Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-107, 24 p.

Kure Atoll

Bowlby, C. E., P. Scoggins, R. Watson, and M. Reddy.

1991. The Hawaiian monk seal, Monachus schauinslandi, at Kure Atoll, 1982-83. U.S.

Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFSC-155, 28 p.

Gilmartin, W. G., R. J. Morrow, and A. M. Houtman.

1986. Hawaiian monk seal observations and captive maintenance project at Kure Atoll,

l981. U.S. Dep. Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-59, 9 p.

Henderson, J. R., and M. R. Finnegan

1990. Population monitoring of the Hawaiian monk seal, Monachus schauinslandi, and

captive maintenance project at Kure Atoll, 1988. U.S. Dep. Commer., NOAA Tech.

Memo. NOAA-TM-NMFS-SWFSC-150, 24 p.

Reddy, M. L.

1989. Population monitoring of the Hawaiian monk seal, Monachus schauinslandi, and

captive maintenance project for female pups at Kure Atoll, 1987. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-123, 37 p.
Appendix A.--Continued.

111

Reddy, M. L., and C. A. Griffith.

1988. Hawaiian monk seal population monitoring, pup captive maintenance program, and

incidental observations of the green turtle at Kure Atoll, 1985. U.S. Dep. Commer.,

NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-101, 35 p.

Van Toorenburg, R. A., W. G. Gilmartin, and J. R. Henderson.

1993. Composition of the Hawaiian monk seal population at Kure Atoll, 1990. Pac. Sci.

47(3):211-214.

Nihoa and Necker Islands

Conant, S.

1985. Observations of Hawaiian monk seals on Necker Island, Northwestern Hawaiian

Islands. 'Elepaio. 6(2):11-12.

Finn, M. A. and M. A. Rice.

1994. Hawaiian monk seal observations at Necker Island, 1993. 'Elepaio. 55(9):55-58.

Morrow, R. J., and E. K. Buelna.

1985. The Hawaiian monk seal and green turtle on Necker Island, 1983. U.S. Dep.

Commer., NOAA Tech. Memo. NOAA-TM-NMFS-SWFC-55, 11 p.

113

Appendix B.--Hawaiian monk seal census form and 1999 census form directions.

(See following pages.)
114


117

1999

CENSUS FORM DIRECTIONS

(Unabridged - Laysan and Lisianski Islands)

This form is used to record all Hawaiian monk seal and green turtle sightings. Turtle sightings are recorded only during

census activities (not during patrols), unless no teworthy event occurs (turtle injured, tagged, tum ored, mating, etc.). At

French Frigate Shoals, do not record a data line for each turtle sighting; instead, write the total for each size/sex

class at the bottom of the page.

All original data should be coded in pencil. Never erase data once you have left the recording site. Instead, cross errors out

with a single line. Field editing is editing before runnin g the data entry and checking program. All field editing by the data

collector should be in blue, and field editing by others should be in red. As soon as you begin the entry and checking

program, the compu ter will assign the computer page number and display it on the screen . At this point, be sure to fill it in

on your census form. All editing after this point should be in orange. After completing the entry and checking program,

check off and initial the ENTERED box on the census form.

A separate data sheet shou ld be filled out for each date, observer, data type, and island within an atoll. If no seals are

present, you should still fill out the information at the top of the census form and write "No seals" in the data area (only

enter the header information). If the island itself is not presen t, indicate this by using 99 for the sector code, leaving the rest

of the (first) line blank. To save paper, you shou ld use a census form with m ultiple headers if you only have a few seals to

record (i.e., at some islands within an ato ll, or when recording incidental sightings b efore or after census or patrol). In

essence, on a census form with multiple headers, each he ader and its associated lines represents a sepa rate data sheet. 

If two people conduct the census, they should have the same weather and the same begin and end time (i.e., both begin at

the same time and place, and proceed in opposite directions until they meet on the other side of the island or islet) and

combine pages into one set. Patrols may be conducted by more than one observer, but page sets are not combined, and

header information may differ between page sets. Patrol observers should attempt to start at roughly the same time. The

sum of all observers' patrol activity for a day should result in on e complete island coun t.

Always record disturban ce. You must be honest about this! Fill out a census form to document disturbance if you

disturb a seal when you are not otherwise collecting data. On a census or atoll count, it is also assumed that condition and

molt data will be taken. 

Do not make up ad ditional codes. If the need for an additional code arises, contact Honolulu.
118

PAGE HEADER

DATA TYPE

C = Census: A complete, timed count on an island begun around 1300. Census is conducted as quickly as

possible (while gathering all information ). Data collected on all seals and turtles. 

A = Atoll-wide census (must be completed within 2 consecutive days). Data collected on all seals and turtles.

B = Behavior patrol: A complete, untimed count where size, sex, ID and disturbance are recorded.

Associations are coded for all seals (Laysan and Lisianski Islands o nly in 1999). Record tu rtles only if

noteworthy observation.

P = Patrol: A complete, un timed count where size, sex , ID, and disturbance are recorded . Behavior data is

not taken. Record turtles only if noteworthy observation.

I = Incidental observation. In this data type, nu ll fields are interpreted as "data not recorded," so co de data

explicitly.

T = Tag status entry for non-active tags (tags not currently on a seal). Record tag status (F or R) in notes

columns. Use this d ata type to log seal haulout tracks at Midw ay Atoll.

COMPUTER PAGE NO.Leave this blank during data collection. It will be assigned and displayed on the screen when

you enter the data. At that time, be sure to fill in the computer page number on your census

form, as this number is need ed for data retrieval.

PAGE Page number within a census or patrol. For examp le, if the census (or patrol) requires three pages, then ma rk

the first page as "page 1 of 3" and so on. If more than 1 person co nducts the census, then combine page

numbers; person A has pages 1 and 2, while person B has pages 3 and 4 of a four-page census day. Header

information (time begin/end , date, number, and weath er) should be the same for all pages w ithin a set.

ISLAND Name of island and atoll, e.g., East, FFS. 

OBSERVER Three initials. If no middle initial, use the first and last block. 

TIME BEGIN and END On a 24-h clock, e.g., 6 p.m. = 1800, for the group of pages.

DATE The date that data are collected (in YY MMD D format).

NUMBER Censuses, Atoll counts, Behavior patrols, and Patrols must be numbered. Each data type will have its own 3

digit number series, starting with 001. For data types other than A, have a separate number series for each islet

within an atoll.

Weather information (except temperature) should be a summary of the entire day up until the end of the census or

patrol, not merely an instantaneous observation. Temperatures taken in the morning are not representative for the

period of data collection.

TEMP. Temperature in degrees Celsius at beginning of census or patro l.

WIND Speed: 0 = no wind, calm (<5 knots)

1 = light breeze (5-15 knots)

2 = strong wind (>15 knots)

Direction: NN,NE,EE,SE,SS,SW,WW,NW

Thus, 2 N N = strong wind from north 

CLOUD Cloud cover: = no clouds 00

01-09 = 10 to 90% cover

10 = 100% cover

PREC. Precipitation: 0 = no precipitation or trace

1 = mist/drizzle

2 = rain
119

3 = intermittent rain

LINES

CONTINUE If the same seal sighting is recorded on several lines for any reason (e.g., additional tag or association,

behavior at a later time, change of beach position), put the original line number you are contin uing from

here. Lines may be continued only within the same page. Fill in the original line as completely as

possible. All fields from TIME through MOLT will be copied from the original line if left blank on the

continuation line. Several lines can h ave the same continuation line number. 

Make a new original line (i.e., do not use continuation lines) for a seal each time that you come abreast of

it on census or patrol. 

TIME The time should b e recorded for each seal sighting, on a 24-h clock.

SECTOR Location on island (e.g., 1-20 on Laysan)

Special codes as follows:

00 = unknown sector

77 = pen

88 = offshore spit/emergent reef

99 = island not present

SIZE Size is estimated using a classification scheme from Stone (19 84), using the following termino logy. Note that seals

are "sized" by length, girth, appearance, and reproductive status, not by age (except pu ps):

Pup Seals born within the calendar year. Newborn pups are black, and weigh ca. 11 to 15 kg. Pups

molt to a silver-gray pelage near weaning. W eaning weight is ca. 50 to 80 kg.

Juvenile Short, slight seals from the length of a weaned pup (about 138 cm) to 20-30 cm longer; includes

yearlings, and other young seals up to 3 years. Distinguished from pups by thinness and

yellowish color.

Subadults Seals perceptibly longer than juven iles up to breeding size; less robust than ad ults, generally with

lighter pelage. Immature seals ca. 3 to 5 or 6 years old.

Adult Reproductively active or breeding size seals at least as long as known breeders. Mature or

probably mature seals. Adult females often have extensive back scars or wounds; adult males

usually dark, including ventrum, and extensively scarred.
120

Male

Female

Code size as follows:

Pups of the year

P0 = Fetus (aborted, clearly pre-term pup)

P = Nursing pup

P1 = Nursing pup, wrinkles

P2 = Nursing pup, no wrinkles

P3 = Nursing pup, blimp, black

P4 = Nursing pup, molting

P5 = Nursing pup, molted

PW = Prematurely weaned/undersized weaned pup (weaned < 2 wks ago and < 90cm girth). Code as

PW at time of weaning, and then can code as W for remainder of season.

W = Weaned pup 

Immatures

I = Immature

J = Juvenile

J1 = Juvenile I

J2 = Juvenile II

S = Subadult

S3 = Subad ult III

S4 = Subad ult IV

Adults

A = Adult

Unknowns

U = Seal of unknown size

Turtles

T = Turtle (lengths from anterior to posterior tip of carapace)

T1 = Turtle, juvenile (<65 cm straight carapace length)

T2 = Turtle, subadult (65 - 80 cm)

T3 = Turtle, adult (>80 cm)

Only code a seal’s sex as known if the ventral is seen, even if you "know" the sex because of the tag, bleach, scars, or

behavior. The o nly exception is that th e mother in a mother/pup pair shou ld be recorded as a fem ale. The sex of a

turtle can only be distinguished externally by tail length, if it is adult-sized.

SEX M = Male

F = Female

U = Unknown

BEACH POS. Location of seal or turtle when observer comes abreast of animal (e.g., if seal is seen in the water from a

distance and yet is on the beach when the observer comes abreast, the seal is recorded as being on the
121

beach). When recording male-male interactions (at Laysan and Lisianski Islands in 1999), make a

continuation line previous to the original line to indicate behaviors or changes in beach position before you

come abreast of the seal.

0 = animal floating or swimming in water (not included in census tally but may be used for

behavioral data or other analysis).

1 = on the beach (or on the fringing reef for Midway Reef Surveys)

9 = on an offshore rock/reef (not included in census tally).

X = data not taken

CONDITION It is assumed that condition is reco rded for all seals (except nursing pups) o n census or atoll count. 

Always record the condition of the mother on her first sighting postpartum, and of the mother and pup on

their first sighting post-weaning, regardless of data type. Alw ays note condition when recording a

survival factor.

Condition codes:

M = medium 

P = probably pregnan t 

F = fat 

T = thin, includes emaciated 

X = data not taken

If the condition code is left blank during an atoll or census coun t, condition is assumed to be medium. 

Codes F and T indicate extreme conditions, seals that are medium-fat, or medium-thin should be coded as

medium.

ID DATA These fields can be used to reco rd either a temporary or permanen t ID number. Use co ntinuation lines to

record both a temporary and permanent number, or two or more temporary numbers. If the seal is

identified, it will not be counted twice on census. To link two sightings o f an unidentified seal during a

survey (i.e. for a cruiser moving ahead of you), assign it a temporary number in a series reserved for

unidentified seals, and code a 6 in the temp ? field.

T/P Indicate whether the number in the subsequent field is a temporary or permanent ID n umber.

T = temporary ID number (or bleach number)

P = permanent ID number

TEMPORARY ID NO. Record the tempo rary ID number (or bleach number) of seal if known; right justified. Th is field

may be used for any temporary number. Use separate number series for bleach and various types

of temporary numbers. If a number is incompletely read, use dashes as place-holders within the

number to indicate missing digits (e.g., incompletely read bleach 152 may be coded -52, 1-2, or

15-). 

? column: 

0 = seal is definitely unmarked; can coexist w ith a temporary numbe r, or with a bleach number if

bleach hasn't taken yet or the numb er has molted off

1 = bleach is present, but the num ber is questionable

4 = partially read bleach number com pleted from other data

5 = incompletely read bleach number, but partial data are certain (if seal can't be identified by ID or

Tag #)

6 = temporary number valid for this survey only (for unident. cruisers moving ahead of you on

census, etc.).

blank = number is certain and complete if present

PERMANENT ID NO. Record the 4-digit permanent ID number of seal if known (put both the island-specific prefix and

next digit in the first box provided).

? column: 

1 = ID number is questionable

blank = ID number is certain and complete if present
122

TAG NO. The complete tag number if known; right justified. If a number is incompletely read, use dashes as placeholders within the number to indicate missing digits. Put the alpha prefix of the temple tag (combined

with tag ? column code = 5) if you can determine the hole drilling pattern, but can't decipher the number

(e.g. A--RT5 for a right tan tag with a 1983 drill pattern). Explain how you came up with the prefix, and

draw the hole drill pattern in Notes.

Record all tag sightings explicitly (i.e., both left and right tag num bers) at least once during your stay. 

During the first weeks of the field camp, note tag condition each time that a tag is sighted. Once the

majority of tags have been resighted, observers can carry a list of tags/individuals that haven't been seen,

and only note tag condition if these tags/individuals are resighted. Also carry a list of broken or lost tags,

and current tag conditions, so that yo u will be aware, and can record, if a specific tag breaks or is lost, or a

tag condition changes during the field season. When a pup is tagged, record the animal handling event on

the census data sheet, and record detailed information (such as all tag numbers, all temporary numbers,

and the permanent nu mber) on a Tagging/H andling card. If a seal is identified via a tag, it is not necessary

to determine and enter its ID number on the census form. The ID number can be determined by computer

later. 

L/R: Tag position 

L = tag on left flipper 

R = tag on right flipper

B = tags on both flippers (enter one tag num ber). This code can be used if the seal has only 2 Temple

tags (one on each flipper).

COL: Color code -see the Tag S ample Kit if unsure of the co lors

Temple tags Other tag types

Y = yellow (FFS) M = metal, M onel 

T = tan/brown (Laysa n) C = clear, PIT tag

G = green (Lisianski) 

B = blue (Pearl & Hermes)

K = silver/gray (Kure) 

R = red (Midway, Necker, Nihoa, Main Islands)

? column:

0 = seal is definitely not tagged on either flipper. To indicate that a seal has lost a tag, code a known

missing tag using tag? code 8. If the tag number is unknowable, write the information in Notes.

1 = seal is tagged, but the number is questionable and the seal is not identifiable from other

information

4 = partially read tag completed from other d ata

5 = incompletely read tag, but partial data are certain (if seal can't be identified by ID o r Temporary

#)

8 = a specific tag is lost/unreadable. Fill out tag position (L/R ) and the tag condition event with

codes L or U. Co mplete the tag number an d color from other data before entry.

blank = tag information is certain if present. Partial data (either complete Tag #, position, or color not

filled) are OK and will be completed by computer if the seal is identified by ID, Temporary #, or

Tag #. The comp uter will only fill blank fields, so an incomplete Tag # must be completed by

hand (use a "4" in the tag ? column).

MOLT Percentage of old pelage lost, optional for pups. However, for weaned pups, record the % molt at time of

tagging. Record molt as 10 0% for at least 1 month post-molt.

blank = no molting evident

0-9 = 1 to 99% molted. 0 = molting, but less than 10%; 1 = 10-19%; 2 = 20-29%; ... 9 = 90-

99%. The first record of a > 2 molt is considered the first day of true molt.

 10 = 100% mo lted, freshly molted, required for th e first month after m olt. Put both

digits of the 10 in the single box provided.

? column: 

0 = seal is definitely not molting
123

1 = seal is molting, but % molt estimate is questionable. May or may not include an estimate in the

molt column

"End of season" editing codes that override molt estimates:

2 = seal in molt

3 = seal pre-molt

4 = seal post-molt

DISTURB The degree to which the seal m ay have been disturbed by ob server. Record disturbance every time a se al is

disturbed, regardless of your activity. The only exception is that you do not need to record a disturbance

for a seal that you are handling (i.e., tagging, disentangling).

0 = no disturbance, or seal merely raised its head or looked at observer - If column blank, 0 is

assumed

1 = seal vocalized, gestured, or moved <2 body lengths

2 = seal alerted to observer and moved >2 body lengths

3 = seal alerted to observer and fled into water

ASSOCIATION DATA Record detailed association data at Laysan and Lisianski Island s in 1999. Don't record

associations involving turtles. If you wish to indicate that a seal was alone, use the O (this

code is alpha, not zero!) behavior cod e. On a census or behavio r patrol data sheet, no code in

any of the association columns means that the seal was alone, whereas on a regular patrol

data sheet, no code may simply mean that no data were taken. It is not necessary to put an O

code for each unassociated animal on census or during behavior patrol at these locations

because it will be filled in by computer. If you are unable to record association data on a

census or behavior patrol at Laysan or Lisianski Island for any reason, indicate this with an X

for the behavior code. Use con tinuation lines to record more than one association. 

An association should either be all blank or have the O, Z, or X behavior only (with no line

number or distance), or have a line number, a distance, and some behavior code (other than

O or X) all present. Don't code behaviors of an animal after it has been disturbed by the

observer (but record the behaviors in N otes).

All associations should be recorded in pairs, i.e., between animals on two different lines. 

You should fill in the line numbers, distances, and behavior codes for both animals involved

in each association. The association line number should refer directly to the line where the

corresponding behavior is coded (i.e., if the corresponding code is on a continuation line,

refer to that particular line, not to the original line or a different continuation line).

Active associations 

1) interactions are recorded for all seals except behavio rs within mother-pup p airs. Only record

 mother-pup interactions during pup exchanges, weanings, or other noteworthy events.

2) must take place within 30 m of observer

3) subjects may be any d istance apart

Spatial associations

1) noted as observer comes abreast of the subject

2) individual seals 

- mother-pup pair (N): any distance

- all others (L): distances <10 m away, record two nearest neighbors, can be on opposite sides

of a log, etc. 

LINE NO. Identity of the other seal in the association. Pu t its line number here (note line num ber refers to within

same census page on ly).

DIST. Closest distance during be havior - both associated lines mu st have the same minimum distance. 

0 = body contact

1 = <2 m

2 = 2-5 m

3 = >5 m (>5 m but <10 m in the case of L behavior code)
124

BEHAVIOR Up to four behaviors may be recorded for each association, bu t L, N, X, and O should not appear together

with other behaviors. Behaviors B and M require distance = 0. Behavior J requires distance of 0 or 1.

With the exception of Bites, Chases, Jousts, and Mounts, only record repetitive, sequential behaviors once

(for example, if an animal approaches three times in a row, code one A). If vocalizations occur, only code

V once (whether or not they are sequential). If a behavior is observed that does not have a code, describe

it in Notes.
125

1) individual seal 

 a) active behavior (directed towards another seal)

 A = approach/investigate/sniff/nu dge

 B = bite (requires distance 0)

 B1 = bite, nip

 B2 = bite, draws blood/breaks skin 

*C = chase 

*C1 = chase, <2 body lengths 

*C2 = chase, >2 body lengths

*D = seal displaces another (see CONTEST RULES)

 F = flee/move away

 F1 = flee/move away, <2 body lengths 

 F2 = flee/move away, >2 body lengths move away

*J = joust (requires distance of 0 or 1)

*J1 = joust <30 s

*J2 = joust >30 s sp ar/fight 

 M = moun t/attempted (requires dist. 0) usually A/S 4 male

 M1 = mo unt/attempted mou nt <30 s

 M2 = mount/attempted mount >30 s

*P = play (typically pup/immature behavior in the water)

 R = submissive roll/presen t ventral 

 V = vocalize

 Z = cruising. A/S4 male only behavior (actual sex may be

unknown). Does not require a line number reference to another seal, but may have one)

b) spatial association

N =mother-pup pair (any distance), does not imply actual

nursing behavior. This is the only association recorded between mother-pup pairs unless

there is an unusual event (i.e., pup switch). If other behaviors are recorded, the N

association must be on the original line for each pair member. 

L = association by location only (distance <10 m apart, for

all except mother-pup pairs)

c) additional codes (Laysan and Lisianski 1999)

*L1 = pair assoc. A/S4 male actively defends an adult female or immature of either sex (actual

sex may be unknown), or establishes a pair relationship with a female or immature after

displacing another male. Code the L1 relationship b oth before and after the contest if a

displacement occurs.

*Q = loser (quitter) 

*W = winner

*Y = tie 

Note: codes Q, W, and Y are used for A/S4 male-male contests only, although the actual sexes may be

unknown (in which case record as though they were known to be males); see the attached CONTEST

RULES . 
126

* requires a corresponding code on the line of the associated seal

Code Corresponding code

C, C1, C2.............F, F1, or F2

D.....................F, F1, or F2

J, J1, J2.............J, J1, and J2 respectively

P.....................P

L1....................L1

Q.....................W

W.....................Q

Y.....................Y

2) nothing nearby

O = no behavior or association

3) no data

X = no association data recorded on Census or Atoll Count

NOTES--There is room to code 2 different notes. Always use the first column first. Code an H if you have handwritten

notes on the observation. Put handwritten notes on the bottom of the census form, labeled by line number. If more than two

note codes apply, use con tinuation lines. 

A = artwork (scars drawn) - attach drawing, labeled with date, island, observer, data type, page number, and

line number 

B = birth, 1st sighting postpartum (mom and pup)

G = seal is green with algae

H = handwritten notes

M = marked, indicate each time a seal is bleached (includes attempts to bleach)

W = weaning, 1st sighting post-weaning (pup)

X = pup exchange, 1st sighting after exchange (mom and pup)

Y = disturbance is to "bystander" s eal during non-survey activity such as tagging, bleach ing, instrumenting,

etc. This includes all "hands o n" research, even if the attempt was un successful.

FOR DATA TYPE "T", STATUS OF NON-ACTIVE TAGS:

F = found 

R = recovered from seal in hand 
127

EVENT These columns are used to record a variety of data. The codes used will depend upon the type of event that you

wish to record. Left justify your codin g:

TYPE CODES CONTENT

COLUMN

F = survival factor ONLY RECORD RESIGHT OF A SURVIVAL FACTOR AS AN EVENT IF THERE

ARE IMPORTANT CHANGES TO DOCUMENT, SUCH AS A NEW WOUND,

HEALING, DEATH, ETC., TRANSCRIBE NOTES TO SURVIVAL FACTOR FORM.

1-3 Survival Factor number 

 4 Factor Type. If seal is dead, always record factor type "D" on

ORIGINAL LINE. For mobbings/ harassments, always code a

census entry with factor type "M" for the victim at the beginning

and end of the incident. Otherwise, you only need to record the

most appropriate factor type if more tha n one applies. 

D = death

W = wound

E = entanglement

V = very thin (emaciated)

I = illness/abnormal (includes eye disease)

M = mobbing/harassment/post-mobbing aggregation

O = other

 5 Participant type (for mobbings/ h arassments/post-mob bing aggreg.

only)

V = victim/subject

M = male aggressor

H = handling of wild seal FOR SEAL CAPTURES OR RELEASES, RECORD DETAILS ON EITHER THE CAPTURE

OR RELEASE FORM. OTHERWISE, RECORD DETAILS ON THE TAGGING/HANDLING

CARD. HANDLING DOES NOT NECESSARILY INVOLVE RESTRAINT OF SEAL.

 1 Handling type

T = tagging (w/ restraint)

M = measuring (includes weighin g)

A = all (both tagging and measuring)

R = remote tagging

D = disentangle (even if not restrained)

I = instrument

B = bleeding

C = take into captivity

F = free from captivity

O = other (includes instrument removal and the

translocation of seals within an atoll) 
128

TYPE CODES CONTENT

COLUMN

P = photo NON-SEAL OR TURTLE PHOTOS ARE NOT CODED ON THE CENSUS FORM,

BUT SHOULD BE RECORDED IN NOTES, AND TRANSFERRED TO THE PHOTO

COM MENT FORM . 

 1 Type of photo

S = slide

P = print

2-3 Roll number (pad with zeros)

4-5 Frame number (pad with zeros)

 6 Side

L = left lateral or flipper

R = right lateral or flipper

D = dorsal side

V = ventral side

B = both (used for rear flippers only)

X = other, describe in handwritten NOTES

 7 Part

H = head

A = anterior body (neck and shoulders)

M = midbody (behind fore-flippers and before posterior)

P = posterior body (behind midbody and before rear

flippers)

F = foreflipper; write whether dorsal/ventral in comm ents

R = rearflipper; write whether dorsal/ventral in comm ents

O = overall view of a particular side

X = other, describe in comments

8 Purpose

I = identification

F = survival factor (link with survival factor EVENT

using continuation lines)

X = other, describe in comments
129

C

D

B B C

D A A

TYPE CODES CONTENT

COLUMN

T = tag condition RECORD TAG CONDITION FOR BOTH SIDES OF EACH TAG AT LEAST ONCE

DURING THE SEASON. IF TAG CONDITION IS RECORDED FOR AN

INCOMPLETELY READ TAG, COMPLETE THE TAG NUMBER (WITH

APPROPRIATE TAG? CODE) PRIOR TO COMPUTER ENTRY.

1 Web 

 A-D = from inner (medial) to outer web.

E = ankle

P = posterior

U =unknown

2 Side of tag, the dorsal tag side is on the dorsal flipper

surface unless the tag is reversed. For Temple Tags, the

dorsal side is the bigger side; for Metal (Monel) tags, the

dorsal side is the "male" side. For PIT tags, code the side

as B (both). 

D = dorsal 

V = ventral 

B = both 

U = unknown

 3 Condition, code U (unreadable) if cannot use tag to ID seal (i.e., if

broken so number gone). Also code U for a PIT tag if you

completely scan for it with a reliable reader but get no reading. If

reader is unreliable, put attempt in Notes and only code PIT tag as

unreadable after 3 separate attempts. Combine the L or U codes

with the tag questionable code of 8. You can combine the tag

questionable code of 8 with other condition codes to describe why

the tag is unreadable (i.e., worn or broken). Unreadable tags can

still be used as partial information to help d etermine a seal’s

identity. Code more than one condition using continuation lines.

B = broken

F = faded color

G = good

L = tag lost 

N = no/partial resin

O = other 

P = pulling out

U = unreadable

V = tag side reversed 

W = no. worn /abraded 
130

CONTEST RULES

1. Size class collapse for contests: all subadults = adults (both sexes)

2. Definition of pair type (depend s on associate of adult male):

• Pair type #1: adult male with adult female (L1)

• Pair type #2: adult male with juvenile or pup of either sex (L1)

• Pair type #3: single adult male not pair type #1 or #2

3. Definition of a male-male co ntest (must conform to at least on e condition below):

• Distance between males = 0

• Either adult male vocalizes (V) or performs a C, D, or J

• If cruiser approaches to beach position $1, regardless of other behaviors

4. Definition of winner or loser adu lt male (Even if the "winner" is no t aware that the other seal flees, if that seal fled in

response to a vocalization, then co de the fleeing seal as the loser (Q) and the othe r seal as the winner (W)):

Case Winner (W) Loser (Q) Tie (Y)

Paired Male vs. Single Male:

(#1 or #2 vs. #3)

i) Original Single Male if has

D

ii) Original Paired

Male otherwise

Has F No Ties

No Ties

Male Paired with Adult Female vs. Male

Paired with Juvenile Seal:

(#1 vs. #2)

i) Original Male Paired w ith

Juvenile if has D

ii) Original Male

Paired with Adult Fem ale

otherwise

Has F No Ties

No Ties

Paired Male vs. Paired Male where bo th pairs

are same type:

(#1 vs. #1 or

#2 vs. #2)

Has D Has F Tie if no D

Single Male vs. Single Male:

(#3 vs. #3)

Has D or C Has F Tie if no D or

C
131

HAWAIIAN MONK SEAL TEMPLE TAGS:

NUMBERING SCHEM E AND HOLE DRILLING PATTERN FOR TAG S APPLIED TO WEANED PUPS

Be sure to code the original tag color, not the color that a tag has faded to. See th e Tag Sample K it.

Original tag color: Faded tag may app ear:

Temple Tags:

 Yellow...................................................White, Lt. Yellow

 Light Tan (A,T,K ,L series @ Laysan ).............Gray, Lt. Yellow, White

 Dark Tan/Brown (later series @ Laysan)..........Red

 Dark Forest Green.....................................Dark Blue, Navy

 Kelly Green (C, P , and Y cohorts)................. --

 Blue (light)...............................................--

 Red.......................................................Orange

 Gray (A,T,K,L,N,F,U,G series @ K ure).........Light Tan

 Silver Gray (600-900,0,Z and later @ Kure)......Metal