iii

EXECUTIVE SUMMARY

In 1996, 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 evaluate (1) the status

and trends of monk seal populations, (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-bysite 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 whole

species, including the total number of pups at the main

reproductive sites, the total of the site-specific mean beach

counts, and the size composition of the seals observed during the

counts (Fig. 1).

Since 1983, the total number of pups born annually 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

population. In 1996, 207 pups were counted at these sites, 94 of

which were born at French Frigate Shoals. Mean beach counts from

the main reproductive sites (again, excluding Midway Atoll),

totaled 381 seals excluding pups, and have remained essentially

unchanged since 1993 (Fig. 1b).

Since the mid 1980s, adults have comprised a growing portion

of the animals counted (Fig. 1c) and, in 1996, the composition of

the counts remained skewed toward adults. This shift in

composition bodes poorly for reproduction in the near future if

older adult females are not replaced by young females reaching

reproductive age. The overall impact from this shift in

composition will be determined by the magnitude of its change and

the length of time that the resulting skewed distribution

persists, neither of which can be reliably predicted at this

time. High mortality of immature seals appears to be a major

factor leading to the shift in composition, particularly at

French Frigate Shoals and Laysan Island.

In 1996, two management activities were conducted by the

Marine Mammal Research Program (Honolulu Laboratory, National

Marine Fisheries Service) to enhance recovery of the species.

First, debris capable of entangling seals was removed from all

study sites and nineteen entangled seals were disentangled by

field biologists. Second, debris was removed from a section of

fringing reef at French Frigate Shoals to reduce hazards to the

seal population, assess the extent of reef fouling, and determine

the feasibility of a large scale debris removal effort.
iv

Fig. 1. Demographic trends of the Hawaiian monk seal, based on

the main reproductive sites (excluding Midway Atoll). a) Number

of pups born. b) Total of mean beach counts, excluding pups. c)
v

Portion of the counts comprised of adults, subadults, and juveniles.

This document describes these and other field studies

conducted during 1996. 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 ................ 4

Censuses and Patrols .............. 4

Reproduction .................. 5

Factors Affecting Survival ........... 6

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

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

Collection of Samples .............. 8

CHAPTER 2. THE HAWAIIAN MONK SEAL ON

FRENCH FRIGATE SHOALS, 1996 ................ 9

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

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

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

Collection of Samples . . . . . . . . . . . . . . 12

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

Seals Collected for Rehabilitation . . . . . 12

Habitat Use Study . . . . . . . . . . . . . 12

Reef Fish and Habitat Assessment . . . . . . 12

Monk Seal Eye Assessment . . . . . . . . . . 12

Debris Removal from Fringing Reef . . . . . 12

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

Population Abundance and Composition . . . . . . 13

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

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

Factors Affecting Survival . . . . . . . . . . . 14

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . 14

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

CHAPTER 3. THE HAWAIIAN MONK SEAL ON

LAYSAN ISLAND, 1996 . . . . . . . . . . . . . . . . . . . . 23

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

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

Individual Identification . . . . . . . . . . . . 26

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

Noteworthy Events . . . . . . . . . . . . . . . . 26

Translocated Adult Males . . . . . . . . . . 26

Oiled Seals . . . . . . . . . . . . . . . . 26

PIT Tag Readability . . . . . . . . . . . . 26

RESULTS . . . . . . . . . . . . . . . . . . . . . . . 27

Population Abundance and Composition . . . . . . 27

Reproduction . . . . . . . . . . . . . . . . . . 27

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

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

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . 28

TABLES . . . . . . . . . . . . . . . . . . . . . . . . 29
viii

(CONTENTS, continued)

Page

CHAPTER 4. THE HAWAIIAN MONK SEAL ON

LISIANSKI ISLAND, 1996 . . . . . . . . . . . . . . . . . . 37

RESEARCH . . . . . . . . . . . . . . . . . . . . . . . 39

Censuses and Patrols . . . . . . . . . . . . . . 39

Individual Identification . . . . . . . . . . . . 39

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

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

Population Abundance and Composition . . . . . . 40

Reproduction . . . . . . . . . . . . . . . . . . 40

Interatoll Movement . . . . . . . . . . . . . . . 40

Factors Affecting Survival . . . . . . . . . . . 40

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

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

CHAPTER 5. THE HAWAIIAN MONK SEAL ON

PEARL AND HERMES REEF, 1996 . . . . . . . . . . . . . . . . 51

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

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

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

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

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

Population Abundance and Composition . . . . . . 54

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

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

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

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

TABLES . . . . . . . . . . . . . . . . . . . . . . . . 55

CHAPTER 6. THE HAWAIIAN MONK SEAL ON

MIDWAY ATOLL, 1996 . . . . . . . . . . . . . . . . . . . . 63

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

Censuses and Patrols . . . . . . . . . . . . . . 65

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

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

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

Sighting Probability Calculations . . . . . 66

RESULTS . . . . . . . . . . . . . . . . . . . . . . . 66

Population Abundance and Composition . . . . . . 66

Reproduction . . . . . . . . . . . . . . . . . . 67

Interatoll Movement . . . . . . . . . . . . . . . 67

Factors Affecting Survival . . . . . . . . . . . 67

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . 67

TABLES . . . . . . . . . . . . . . . . . . . . . . . . 69

CHAPTER 7. THE HAWAIIAN MONK SEAL ON

KURE ATOLL, 1996 . . . . . . . . . . . . . . . . . . . . . 77
ix

(CONTENTS, continued)

Page

RESEARCH . . . . . . . . . . . . . . . . . . . . . . . 79

Censuses and Patrols . . . . . . . . . . . . . . 79

Individual Identification . . . . . . . . . . . . 79

Collection of Samples . . . . . . . . . . . . . . 80

RESULTS . . . . . . . . . . . . . . . . . . . . . . . 80

Population Abundance and Composition . . . . . . 80

Reproduction . . . . . . . . . . . . . . . . . . 80

Interatoll Movement . . . . . . . . . . . . . . . 80

Factors Affecting Survival . . . . . . . . . . . 81

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . 81

TABLES . . . . . . . . . . . . . . . . . . . . . . . . 83

CHAPTER 8. THE HAWAIIAN MONK SEAL ON

NIHOA AND NECKER ISLANDS AND GARDNER PINNACLES, 1996 . . . 91

RESEARCH . . . . . . . . . . . . . . . . . . . . . . . 93

Censuses and Patrols . . . . . . . . . . . . . . 93

Individual Identification . . . . . . . . . . . . 93

Collection of Samples . . . . . . . . . . . . . . 94

RESULTS . . . . . . . . . . . . . . . . . . . . . . . 94

Population Abundance and Composition . . . . . . 94

Reproduction . . . . . . . . . . . . . . . . . . 94

Interatoll Movement . . . . . . . . . . . . . . . 94

Factors Affecting Survival . . . . . . . . . . . 95

ACKNOWLEDGMENTS . . . . . . . . . . . . . . . . . . . 95

TABLES . . . . . . . . . . . . . . . . . . . . . . . . 97

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . 103

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 1996

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 Southwest Fisheries Science Center, Honolulu

Laboratory, NMFS 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 populations,

(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 Reef), and

1983 (Midway Atoll). Nearly every year thereafter, field camps

of several days to 9 months were established to monitor and

enhance the recovery of this species. Limited population

monitoring has also been conducted at Nihoa and Necker Islands,

where pup production is spatially limited by availability of

haulout area. Reports summarizing past NMFS research are listed

in Appendix A.

In 1996, the objectives of Hawaiian monk seal research were

to (1) conduct beach counts (censuses), (2) tag weaned pups and

immature seals for permanent identification, (3) identify other

seals by previously applied tags and by natural or applied

markings, (4) monitor reproduction, survival, injuries,

entanglements, interatoll movements, disappearances, and deaths,

(5) perform necropsies, (6) collect scat and spew samples for

food habit analysis, (7) collect tissue samples for DNA analysis

of paternity patterns and genetic variation within and among

populations, and (8) inventory, sample, and destroy debris

capable of entangling seals. Location-specific objectives and

summaries of data collected during the 1996 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.

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 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
4

size for comparison among years and locations. Data collected on

each seal observed during censuses included size class (ranging

from pup to juvenile, subadult, and adult size as described in

Stone, 1984); 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 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 or mobbings), (2) animal

handling, (3) photography, and (4) documentation of tag condition

(e.g., good or broken). In addition, behavior 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

three times at Nihoa Island, once each at Necker Island and

Gardner Pinnacles, or every 2 to 7 days (at all other locations),

starting at 1300 Hawaii standard time when possible, using census

methods and criteria outlined in Johanos et al. (1987). Atollwide counts for locations with more than a single island (French

Frigate Shoals, Pearl and Hermes Reef, 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 samples. Island-specific 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, special efforts

were directed toward documentation of (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.
5

Reproduction

Parturient females were identified, and birth and weaning

information were recorded. Because parturient females will nurse

pups other than their own (Boness, 1990), efforts were made to

identify pups and document changes in nursing relationships from

birth to weaning. A pup exchange occurred when the pups of two

lactating females were switched. Most frequently, such exchanges

occurred during an aggressive interaction between the two

females. On other occasions, a mother and pup became separated,

and one or both seals then actively sought and obtained another

nursing relationship.

The average nursing period was calculated for the pups at

each location. The average lactation period of parturient

females was also calculated for seals at FFS because higher

population density and frequent pup exchanges (Boness, 1990) 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 in nursing relationships 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

A wide range of injuries were observed. The origins of

these 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 more

than one digit (either foreflipper or hindflipper); (3) at least

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). We did not include injuries that were

healed when first observed.

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
6

1

Reference to trade names does not imply endorsement by the

National Marine Fisheries Service, NOAA.

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, or (2) the seal was in deteriorating

condition (loss of weight, enlargement of abscesses, sloughing of

skin) and disappeared at least 10 surveys or 1 month before the

end of data collection (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 if they simultaneously involved more than one male

aggressor or resulted in at least 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 by tags, bleach marks, scars, or natural markings.

After weaning, all pups were tagged on each hind flipper with a

colored plastic Temple Tag,®1 uniquely coded to indicate island

or atoll population, year of birth, and individual ID (Gilmartin

et al., 1986). In addition, two passive integrated transponder

(PIT) tags were implanted subcutaneously in the dorsum of each

weaned pup (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, 1982 at Lisianski Island,

1983 at Laysan Island and Pearl and Hermes Reef, 1984 at French

Frigate Shoals, and 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
7

also been implanted subcutaneously in the dorsum of most weaned

pups.

In 1996, untagged immature seals were tagged with Temple

Tags uniquely coded to indicate that their ages and birth

locations were unknown. Immature seals with lost or broken tags

were retagged to maintain their identities.

At five locations (Laysan and Lisianski Islands, Pearl and

Hermes Reef, Midway Atoll, and Kure Atoll), seals were bleachmarked for individual identification (Stone, 1984), using the

solution described in Johanos et al. (1987). Molting seals were

re-marked to maintain their identities. At Laysan and Lisianski

Islands, nursing pups were also bleached prior to molt.

Tags, scars, natural markings, and any applied bleach marks

were sketched on an individual scar card, 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.

Population size and composition were determined at locations

where all seals were identified; partial composition was

determined where all seals within certain size and sex classes

were identified. These statistics included all individuals seen

alive at the location during the interval from March through

August and all pups born during the year. Captive seals were

included if they were released in the current year. If a seal

was seen at more than one location during March-August, it was

included in the population where it was first seen unless it

pupped at another location. A parturient female was always

included in the population where it pupped, if it was seen there

anytime during March-August.

The movement of seals between island or atoll populations

confounds the estimation of population size and composition when

the study period is short (i.e., less than 1 month). 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 Reef). These seals may be transient visitors,

and additional study is needed to distinguish them from seals

that reside at Midway Atoll.

Measurements of Seals

Pups were measured to determine their condition, growth

patterns, and the relationship between size and survival.

Measurements were taken as soon after weaning as possible and

included straight dorsal length (Winchell, 1990) and axillary

girth (American Society of Mammalogists, 1967).
8

Collection of Samples

Samples were collected for DNA analysis, pathology analysis,

investigation of food habits, and documentation of marine debris.

Tissue samples for DNA analysis were collected during tagging

efforts for all newly tagged or retagged seals, and during

necropsies on recently dead seals. Samples of sloughed epidermis

and fur from molting seals were also collected at Laysan Island

on an opportunistic basis for DNA analysis. The primary

objectives of genetic analyses are to investigate paternity

patterns and determine genetic variability within and among

populations.

For each dead seal recovered, an external examination was

made, photographs were taken, 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 (Alcorn, 1984) for

analysis of food habits. Emphasis was placed on collecting these

samples from seals of known size and sex class, but samples from

seals of unknown size and sex class were also collected.

Nets, lines, ropes, and other debris items capable of

entangling seals and turtles were inventoried and destroyed,

following the methods in Johanos and Kam (1986).
9

CHAPTER 2. THE HAWAIIAN MONK SEAL ON

FRENCH FRIGATE SHOALS, 1996

Mitchell P. Craig, Nicole M. Adimey, Kimberly Raum-Suryan, and

Allison Veit

11

The largest island population 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 10 permanent

islands and 7 semipermanent sand spits (Fig. 2.1).

RESEARCH

The National Marine Fisheries Service (NMFS) began research

on Hawaiian monk seals at FFS in 1982. In 1996, research was

conducted by NMFS during April 20-September 1. Incidental

observations were recorded by U.S. Fish and Wildlife Service

(USFWS) personnel during the rest of the year. The perimeters of

six of the larger islands were divided into sectors using

artificial or natural landmarks. Research objectives specific to

this population in 1996 included (1) investigation of habitat use

patterns using satellite-linked telemetry, seal-mounted video

cameras, and GPS telemetry, (2) assessment of nearshore prey

availability and habitat structure, and (3) visual examination of

wild monk seal eyes for evidence of corneal opacities or symptoms

consistent with those observed in captive seals.

Censuses and Patrols

Atoll censuses (n = 10) were conducted every 7 days, on

average, from May 16 to July 18. Each atoll census began between

1000 and 1100 Hawaii standard time and ended between 1600 and

1800. Round Island and Mullet Island were censused from a boat,

while the remaining islands were censused on foot by one or two

persons.

Patrols were conducted on noncensus days. East, Mullet,

Round, and Whaleskate Islets were visited every 3-4 days to

monitor pupping activity. Patrols of Tern Island were conducted

every 3 days.

Individual Identification

A total of 447 individuals (353 excluding pups) were

identified by existing or applied tags, scars, or natural

markings. Most weaned pups (n = 67) were tagged with Temple

Tags; 49 of these same pups were tagged with passive integrated

transponder (PIT) tags. One immature seal was retagged with

Temple Tags. Four adult males were tagged during

instrumentation. One juvenile male born in December 1995 was

tagged.

Collection of Samples
12

Seventy-five scat and spew samples were collected. Tissue

samples were collected from 52 seals during tagging. Blood

samples were collected from five males and one female.

Necropsies were performed on three dead seals found at the study

site. Tissue samples were collected from all necropsied seals.

In total, twelve pieces of potentially entangling debris were

inventoried and destroyed.

Special Studies

Seals Collected for Rehabilitation

No seals were collected for rehabilitation.

Habitat Use Study

In April and May, 10 adult males were instrumented with

satellite-linked time-depth recorders as part of a habitat use

study. One of these 10 instruments was lost and 7 instruments

were retrieved in July and August. The remaining 2 instruments

were still attached and functioning as of September 1 but were

seen lost in October. During April and May three adult males

were instrumented with experimental GPS (Global Positioning

System) units. These GPS units were retrieved in 4 to 18 days.

During August seven adult males were instrumented with video

cameras and two adult males were instrumented with GPS units.

The seven cameras were retrieved in 3 to 19 days. One GPS unit

was lost within 4 days and the other was retrieved 92 days later.

During October, five adult females and four adult males were

instrumented with satellite-linked time-depth recorders. One

satellite tag was lost from an adult female within a week after

application, and the remaining tags were retrieved in January

1997.

Reef Fish and Habitat Assessment

In August the Ecosystem and Environmental Investigation of

the Honolulu Laboratory, NMFS, continued ongoing habitat

assessment. They repeated a reef fish survey, continued testing

octopus trapping methods, and continued video camera transects

around and within the atoll.

Monk Seal Eye Assessment

In August, the eyes of 120 wild seals were assessed from a

distance by a veterinarian investigating an eye disease occurring

in captive Hawaiian monk seals.

Debris Removal from Fringing Reef
13

Personnel aboard the NOAA ship Townsend Cromwell removed

debris from a section of fringing reef between Whale-Skate and

Tern Islands to reduce these hazards to monk seals and other

marine life, assess the extent of reef fouling, and determine the

feasibility of a large-scale debris removal effort.

RESULTS

Population Abundance and Composition

The means (±SD) for 10 atoll censuses were 160.3 seals

(±26.9) including pups, and 120.5 seals (±17.5) excluding pups

(Table 2.1). The total spring-summer population included 159

immature individuals (subadults, juveniles, and pups), of which

64 were subadults or juveniles (Table 2.2). Although the total

numbers of adult males and females were not obtained due to our

inability to identify all individuals, it is estimated that less

than seven individuals of each sex remained unidentified at the

end of the field season. The numbers of tagged known-age seals

born at FFS during the period from 1984 to 1995 and resighted

there in 1996 are summarized in Table 2.3.

Reproduction

At least 95 pups were born: 76 were weaned, 17 died or

disappeared prior to weaning, and 2 were nursing at the end of

this study (Table 2.4a). No fetuses were found. Nursing periods

and measurements of weaned pups are summarized in Table 2.4b. A

total of 166 adult-sized females were identified and 89 (54%) of

those were parturient. The birth rate was 57% (56/98) for

untagged adult females (>12 years old) and 49% (33/68) for tagged

females of adult size (12 years old). Parturient females were

more likely to be identified during lactation, which probably

biased the estimates of birth rate upward. As noted above, our

best estimate is that less than seven adult-sized females

remained unidentified at FFS. The mean (±SD) lactation period

was 38.3 d (±4.2 d). At least seven pups were fostered by

mothers other than their own.

Interatoll Movement

Interatoll movement was documented for 22 seals that made a

total of 33 movements between FFS and either Nihoa Island, Necker

Island, Brooks Banks, Gardner Pinnacles, Laysan Island, or

Lisianski Island (Tables 2.5a and b).

Factors Affecting Survival
14

Attacks by large sharks, mounting attempts by males,

entanglement, emaciation, and other/unknown factors resulted in

58 life-threatening conditions, which led to the confirmed deaths

of 11 animals and the probable death of 22 seals (Table 2.6).

One incident of adult male aggression was observed and one seal

was known to have died following male-mounting incident. Two

emaciated seals died. One seal was entangled and released by

observers.

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.
TABLES
17

Table 2.1.--Summary statistics for atoll censuses ( n = 10) of

Hawaiian monk seals at French Frigate Shoals from

May 16 to July 18, 1996.

Size/Sex

Mean number of

individuals

Standard

deviation

Adults 102.3 16.4

Male 30.5 4.9

Female 62.5 15.4

Unknown 9.3 3.7

Subadults 7.7 2.5

Male 2.5 0.7

Female 4.6 2.1

Unknown 0.6 1.0

Juveniles 10.5 2.3

Male 4.0 1.6

Female 6.0 2.0

Unknown 0.5 1.0

Pups 39.8 10.6

Male 12.0 6.5

Female 7.7 3.7

Unknown 20.1 4.8

Nonpup Total 120.5 17.5

Grand Total 160.3 26.9
18

Table 2.2.--Composition of the Hawaiian monk seal population at

French Frigate Shoals during the spring and summer of

1996. Includes all pups born during the calendar

year.

Number of seals

Size Male Female Unknown Total

Sex ratio

male:female

Adults 121a 166a 0 287a 0.7:1

Subadults 10 20 0 30 0.5:1

Juveniles 15 19 0 34 0.8:1

Pups 47 37 11 95 1.3:1

Nonpup Total 146a 205a 0 351a 0.7:1

Grand Total 193a 242a 11 446a 0.8:1 a

The adult population was not totally enumerated. It is

estimated that less than 7 adult individuals of each sex

remained unidentified at the end of the field season.
19

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

Frigate Shoals Island and resighted there in 1996.

Age

(years) Sex

Number originally

tagged

Number resighted

in 1996

12 Male

Female

49

43

11

16

11 Male

Female

48

38

4

10

10 Male

Female

52

48

11

19

9 Male

Female

55

51

12

16

8 Male

Female

52

62

5

8

7 Male

Female

51

50

7

5

6 Male

Female

39

40

1

2

5 Male

Female

24

44

1

4

4 Male

Female

36

55

2

8

3 Male

Female

40

39

7

3

2 Male

Female

47

48

2

6

1 Male

Female

29

26

8

8
20

Table 2.4a.--Summary of Hawaiian monk seals born at French

Frigate Shoals in 1996.

Event

Number of pups

Male Female Unknown Total

Born 47 37 11 95

Died/probably died

prior to weaning

2 5 10 17

Still nursing 2a 00 2

Weaned 43 32 1 76b

Tagged 39 30 0 69c

a

Three male pups were nursing in October 1996; one is known to

to have weaned and was tagged in January 1997.

b

Seven weaned pups (4 male, 2 female, and 1 sex unknown)

disappeared prior to tagging, lost hindflippers, or were too

severely injured to tag.

c

Two weaned pups (1 male, 1 female) were tagged in January 1997.

Table 2.4b.--Summary of nursing periods and measurements of

weaned pups at French Frigate Shoals in 1996.

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 39.8 105.4 126.2

St. Dev. 5.3 9.0 7.2

n 3 48 48
21

Table 2.5a.--Known movement of Hawaiian monk seals to French

Frigate Shoals from other locations in 1996,

summarized by movements between two locations. Some

seals made more than one trip.

Original location Number, size, and sex class

Nihoa Island 1 adult male,

1 adult female

Necker Island 1 adult male,

3 adult females

Brooks Bank 1 adult male,

1 adult female

Gardner Pinnacles 2 adult males

Laysan Island 2 adult females,

1 subadult female

Lisianski Island 1 subadult male

Table 2.5b.--Known movement of Hawaiian monk seals from French

Frigate Shoals to other locations in 1996,

summarized by movements between two locations. Some

seals made more than one trip.

Destination Number, size, and sex class

Necker Island 4 adult males,

3 adult females,

1 subadult female

Brooks Bank 1 adult male,

1 adult female

Gardner Pinnacles 4 adult males

Laysan Island 1 adult male,

4 adult females
22

Table 2.6.--Factors affecting Hawaiian monk seal survival at

French Frigate Shoals in 1996.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Adult Male

Female

5

1

5

1

0

0

0

0

Juvenile Female 1 1 0 0

Weaned pup Male

Female

2

4

2

4

0

0

0

2

Nursing pup Female

Unknown

1

1

1

1

1

0

0

1

Mounting by Males

Adult Female 1 1 0 0

Weaned pup Male

Female

7

3a 7

3

1

0

3

1

Entanglement

Adult Female 1b 00 0

Emaciation

Adult Male

Female

1

2

0

0

1

0

0

1

Juvenile Male

Female

4

1

1

0

1

0

1

1

Other/Unknown

Adult Male

Female

2

2

2

1

0

1

0

0

Weaned pup Male

Female

Unknown

1

2

1

1

0

0

0

1

0

0

1

1

Nursing pup Male

Female

Unknown

2

4

9

1

2

0

2

3

0

0

1

9 a

A seal was observed being mounted on August 18 by one adult male, YN22.

b

Seal was released by observers.
CHAPTER 3. THE HAWAIIAN MONK SEAL ON

LAYSAN ISLAND, 1996

Brenda L. Becker, Hannahrose M. Nevins, Joshua Adams,

and Matthew R. Rutishauser

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 major haulout and

pupping locations of the Hawaiian monk seal.

RESEARCH

The National Marine Fisheries Service (NMFS) began research

on Hawaiian monk seals at Laysan Island in 1981. In 1996,

research was conducted by NMFS during March 15-July 30, and

incidental observations were recorded by U.S. Fish and Wildlife

Service (USFWS) personnel during the rest 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 population in 1996 included

identifying all seals, assessing maternity and pup exchanges,

retagging seals whose tags were unreadable, monitoring the

readability of PIT tags, describing male behavioral patterns and

aggression to determine if the removal of 22 adult males from

Laysan Island in 1994 reduced the incidence of mobbing, and

identifying any of those males that may have returned to Laysan

after translocating to the main Hawaiian Islands.

Censuses and Patrols

Censuses and patrols were scheduled to ensure that the

entire island perimeter was monitored at least once each day

during March 19-July 27. Censuses (n = 23) were conducted by two

observers every fifth day from April 5 to July 24. Each census

began at 1300 Hawaii standard time and continued for 2.2 to 3.1

hours.

Standardized behavior patrols were conducted on noncensus

days to assess activity patterns of adults and large subadults,

document male aggression, and detect mobbing incidents. During

these patrols (n = 98), attention was directed out to sea as much

as possible because mobbings have been observed most frequently

in the water.
26

Individual Identification

A total of 262 individuals (215 excluding pups) were

identified by existing or applied tags, bleach marks, scars, or

natural markings. Bleach marks were applied to 226 seals,

including 44 nursing pups. All weaned pups ( n = 44) and 1

juvenile female seal were newly tagged with Temple Tags; all but

2 weaned pups also received passive integrated transponder (PIT)

tags. One hundred seals (65 males, 35 females) were retagged

with Temple Tags.

Collection of Samples

One hundred twenty-seven scat and spew samples were

collected. Tissue samples were collected from 141 seals during

tagging. Two necropsies were performed and tissue samples were

collected from one dead seal. Molt samples were collected from

29 seals. In total, 586 pieces of potentially entangling debris

were inventoried and destroyed with the exception of one that was

removed and collected from an entangled seal.

Noteworthy Events

Translocated Adult Males

Twenty-two adult male seals were collected from Laysan

Island in 1994; one male died shortly after capture and the

remaining twenty-one males were translocated to the main Hawaiian

Islands. None of the translocated males had migrated back to

Laysan Island, but one was observed at Nihoa Island in 1996.

Oiled Seals

Eleven of seventeen seals observed with oiled pelage on

Laysan Island in the spring of 1993 were sighted there in 1996.

These seals appeared to be in good health, but sublethal or longterm effects could not be evaluated. Of the six not sighted in

1996, one seal was last seen in 1995, four were last seen in 1994

(one of these, an adult male, was translocated to the main

Hawaiian Island in 1994), and one was last seen in 1993.

PIT Tag Readability

Excluding pups of the year, 96 animals in the current

Laysan Island population have one or two PIT tags for a total of

181 PIT tags. Only 3 (2%) of the 131 tags scanned in 1996 were

unreadable.

RESULTS
27

Population Abundance and Composition

The means (±SD) for 23 censuses were 110.7 seals (±15.6)

including pups, and 86.5 seals (±8.9) excluding pups (Table 3.1).

The total spring-summer population was 261 individuals, 214

excluding pups (Table 3.2). The sex ratios of nonpup immature

seals and adults were ca. 0.9:1 (35 males:37 females) and 0.9:1

(67 males:74 females), respectively. The sex ratio for older

(>13 years of age) and unknown aged adults was slightly skewed

toward males at ca. 1.1:1 (38 males:36 females), whereas the

ratio for younger adults (<13 years of age) was ca. 0.8:1 (29

males:38 females). The numbers of tagged known-age seals born at

Laysan Island during the period from 1983 to 1995 and resighted

there in 1996 are summarized in Table 3.3.

Reproduction

At least 47 pups were born: 44 were weaned, 2 died prior

to weaning, and 1 disappeared prior to weaning (Table 3.4a).

Nursing periods and measurements of weaned pups are summarized in

Table 3.4b. Forty-seven of 74 (64%) adult-sized females were

parturient. At least 9 pup exchanges occurred between 12 nursing

females; none of these incidents were observed. No weaning

events were observed. One unusual temporary weaning (i.e., a

nursing female abandoned her pup, and then returned) was

documented.

Interatoll Movement

Interatoll movement was documented for 16 seals that made a

total of 19 movements between Laysan Island and haulout sites at

French Frigate Shoals or Lisianski Island, or probable foraging

areas at Northampton Seamounts or Maro Reef (Tables 3.5a and b).

Two seals sighted on Laysan Island in 1996 had not been sighted

at any location for 1 (an adult female) or 4 (an adult male)

years.

Factors Affecting Survival

Attacks by large sharks, mounting attempts by males,

entanglement, and other/unknown factors led to 35 lifethreatening conditions, which resulted in the confirmed deaths of

3 animals and the probable deaths of 3 other seals (Table 3.6).

One post-mobbing event was observed and involved 7 adult males

with an adult female who sustained serious injuries. No seals

were known to have died or disappeared following male- mounting

incidents. Four seals were entangled: two escaped by themselves

by 1997, and two were disentangled by researchers.

ACKNOWLEDGMENTS
28

We acknowledge the support of the U.S. Fish and Wildlife

Service, Hawaiian Islands National Wildlife Refuge staff and

thank the captains and crew members of the NOAA ship Townsend

Cromwell and the U.S. Coast Guard Cutter Washington. Special

thanks are extended to Brian Allen, Rebecca Bernard, Monette

Boswell, Leslie Leroux, Amber Pairis, Mike Schultz, Drew

Wettergreen, Peter Winch, and NOAA Corps officers Lt. Carolyn

Sramek and Lt. (j.g.) Kurt Zegowitz for their data collection and

tagging assistance. We also thank the captain of the F/V Fortuna

for reporting the seal sighting at Northampton Seamounts.
TABLES
31

Table 3.1.--Summary statistics for censuses ( n = 23) of Hawaiian

monk seals at Laysan Island from April 5 to

July 24, 1996.

Size/Sex

Mean number of

individuals

Standard

deviation

Adults 49.0 5.7

Male 20.2 4.6

Female 28.5 5.3

Unknown 0.3 0.8

Subadults 13.0 4.0

Male 7.3 2.3

Female 5.4 2.2

Unknown 0.4 0.6

Juveniles 24.3 4.2

Male 11.0 3.0

Female 12.9 2.1

Unknown 0.4 0.7

Pups 24.3 10.2

Male 13.3 5.8

Female 10.7 4.6

Unknown 0.3 0.8

Nonpup Total 86.5 8.9

Grand Total 110.7 15.6
32

Table 3.2.--Composition of the Hawaiian monk seal population at

Laysan Island during the spring and summer of 1996.

Includes all pups born during the calendar year.

Number of seals

Size Male Female Unknown Total

Sex ratio

male:female

Adults 67 74 1 142 0.9:1

Subadults 15 12 0 27 1.3:1

Juveniles 20 25 0 45 0.8:1

Pups 24 22a 1a 47 1.1:1

Nonpup Total 102 111 1 214 0.9:1

Grand Total 126 133 2 261 1.0:1

a

One neonatal pup death.
33

Table 3.3.--Summary of tagged known-age seals born at Laysan

Island and resighted there in 1996.

Age

(years) Sex

Number originally

tagged

Number resighted

in 1996

13 Male

Female

10

10

1

6

12 Male

Female

16

13

2

5

11 Male

Female

16

14

1

5

10 Male

Female

15

17

2

2

9 Male

Female

13

15

3

5

8 Male

Female

23

17

6

3

7 Male

Female

16

13

3

3

6 Male

Female

7

9

2

3

5 Male

Female

18

13

8

8

4 Male

Female

18

14

2

3

3 Male

Female

23

14

5

3

2 Male

Female

18

29

8

11

1 Male

Female

16

21

12

13
34

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

in 1996.

Event

Number of pups

Male Female Unknown Total

Born 24 22 1 47

Died prior to weaning 0 1 1 2

Disappeared prior to

weaning

10 0 1

Weaned 23 21 0 44

Tagged 23 21 0 44

Table 3.4b.--Summary of nursing periods and measurements of

weaned pups at Laysan Island in 1996. 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 36.6 104.5 123.8

St. Dev. 3.8 6.9 5.4

n 42 42 42
35

Table 3.5a.--Known movement of Hawaiian monk seals to Laysan

Island from other locations in 1996, summarized by

movements between two locations. One seal made more

than one trip.

Original location Number, size, and sex class

French Frigate Shoals 1 adult male,

4 adult females

Lisianski Island 4 adult females,

1 subadult female

Maro Reef 1 adult male

Table 3.5b.--Known movement of Hawaiian monk seals from Laysan

Island to other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Destination Number, size, and sex class

French Frigate Shoals 2 adult females,

1 subadult female

Lisianski Island 1 adult female,

3 subadult females

Northampton Seamounts 1 adult female
36

Table 3.6.--Factors affecting Hawaiian monk seal survival

at Laysan Island in 1996.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Adult Male

Female

Unknown

3

2

1

3

2

0

0

0

0

0

0

1

Juvenile Male 1 1 0 0

Mounting by Males

Adult Female 5a 50 0

Subadult Female 1 1 0 0

Weaned Pup Male 2 2 0 0

Entanglement

Subadult Male 1b 00 0

Juvenile Male 1c 10 0

Weaned Pup Male

Female

1d

1b 1

0

0

0

0

0

Other/Unknown

Adult Male

Female

3e

3

2

3

0

0

0

0

Subadult Female 1 1 0 0

Juvenile Male

Female

2

2f 2

1

0

0

0

0

Weaned Pup Male

Female

1g

1h 0

0

0

1

1

0

Nursing Pup Male

Female

Unknown

1i

1j

1k

0

0

0

0

1

1

1

0

0 a

Post-mobbing event observed; seven adult males with a severely injured seal.

b

Released by researchers; no injury resulted from entanglement.

c

Seal disentangled itself by 1997, but was injured.

d

Seal escaped by itself but was injured.

e

Seal had seizure during capture for retagging, appeared to fully recover.

f

One seal had an opaque, blind eye.

g

Seal was prematurely weaned and not resighted after weaning date.

h

Too decomposed to confirm cause of death, but mounting scratches present.

i

Disappeared near weaning age; probably swept away in high tide during night.

j

Mother wounded by large shark within 2 months prior to parturition.

k

Mother had abnormal skin condition and molted early in relation to the end

of nursing period (death of her pup).
CHAPTER 4. THE HAWAIIAN MONK SEAL ON

LISIANSKI ISLAND, 1996

Joy A. Seymour, Lucy W. Keith, Katherine W. McFadden, Kara A.

Blake, and Brenda L. Becker

39

Lisianski Island (lat. 26°02'N, long. 174°00'W) is one of

the major 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.

RESEARCH

The National Marine Fisheries Service (NMFS) began research

on Hawaiian monk seals at Lisianski Island in 1981. In 1996,

research was conducted by NMFS during March 14-July 28. The

perimeter of the island (ca. 5.2 km) was divided into 20 sectors

using artificial or natural landmarks (Fig. 4.1). Research

objectives specific to this population in 1996 included

identification of all seals, assessment of maternity and pup

exchanges, and description of adult male behavioral patterns and

aggression.

Censuses and Patrols

Censuses and patrols were scheduled to ensure that the

entire island was monitored at least once each day during March

27-July 24. Censuses (n = 22) were conducted by two observers

every fifth day from March 31 to July 24, beginning at 1300

Hawaii standard time and continuing for 1.2 to 2.1 hours.

Standardized behavior patrols were conducted on noncensus

days to assess activity patterns of adults and large subadults,

document male aggression, and detect mobbing incidents. During

these patrols (n = 81), attention was directed out to sea as much

as possible because mobbing has been observed most frequently in

the water.

Individual Identification

A total of 202 individuals (178 excluding pups) were

identified by existing or applied tags, bleach marks, scars, or

natural markings. Bleach marks were applied to 136 seals,

including 18 nursing pups. All weaned pups ( n = 22) were tagged

with Temple Tags, and all but one also received passive

integrated transponder (PIT) tags. One subadult and one juvenile

female were retagged with Temple Tags.

Collection of Samples

One hundred and seven scat and spew samples were collected.

Tissue samples were collected from 17 seals during tagging. A

necropsy was performed and tissue samples were collected from one

dead seal. In total, 516 pieces of potentially entangling debris

were inventoried and destroyed, with the exception of five pieces

which were removed and collected from entangled seals.

RESULTS
40

Population Abundance and Composition

The means (±SD) for 22 censuses were 77.7 seals (±10.0)

including pups, and 63.4 seals (±8.3) excluding pups (Table 4.1).

The total spring-summer population was 201 individuals, 177

excluding pups (Table 4.2). The sex ratios of nonpup immature

seals and adults were ca. 0.9:1 (23 males:26 females) and 1.6:1

(78 males:50 females), respectively. The sex ratio for older

(>14 years of age) and unknown aged adults was strongly skewed

toward males at ca. 2.6:1 (52 males:20 females), whereas the

ratio for younger adults (<14 years of age) was ca. 0.9:1 (26

males:30 females). The numbers of tagged known-age seals born at

Lisianski Island during the period from 1982 to 1995 and

resighted there in 1996 are summarized in Table 4.3.

Reproduction

At least 24 pups were born: 22 were weaned, 1 died prior

to weaning, and 1 was still nursing at the end of this study

(Table 4.4a). Nursing periods and measurements of weaned pups

are summarized in Table 4.4b. Twenty-four of fifty (48%) adultsized females were parturient. At least 9 pup exchanges occurred

between 11 nursing females; none of these incidents were

observed.

Interatoll Movement

Interatoll movement was documented for 12 seals that made a

total of 13 movements between Lisianski Island and either French

Frigate Shoals, Laysan Island, or Pearl and Hermes Reef (Tables

4.5a and b).

Factors Affecting Survival

Attacks by large sharks, mounting attempts by males,

entanglement, emaciation, and unknown factors led to 14 lifethreatening conditions, which resulted in the confirmed death of

2 animals and probable death of 1 seal (Table 4.6). One mobbing

event was observed and involved 5 adult males with an adult

female who was uninjured. No seals were known to have died or

disappeared following male-mounting injuries. Seven

entanglements involving six seals were observed: in one event,

the seal escaped by itself and in six incidents the seal was

released by researchers. In addition to the cases summarized in

Table 4.6, a pup was extremely undersized (63 cm axillary girth)

after completing a full nursing period (43 days). The seal was

observed through the end of this study, though it was not

expected to survive the year.
41

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife

Service, Hawaiian Islands National Wildlife Refuge staff. We

thank the captains and crew of the NOAA ship Townsend Cromwell

and the U.S. Coast Guard Cutter Washington, and the U.S. Coast

Guard Barbers Point flight operations for logistical assistance.
TABLES
45

Table 4.1.--Summary statistics for censuses ( n = 22) of Hawaiian

monk seals at Lisianski Island from March 31 to

July 24, 1996.

Size/Sex

Mean number of

individuals

Standard

deviation

Adults 47.4 6.8

Male 26.0 4.9

Female 20.3 4.2

Unknown 1.1 1.2

Subadults 12.0 4.2

Male 5.6 2.6

Female 5.8 2.5

Unknown 0.5 1.1

Juveniles 4.0 2.0

Male 1.5 1.0

Female 2.4 1.5

Unknown 0.2 0.5

Pups 14.3 3.5

Male 6.0 2.0

Female 7.9 2.7

Unknown 0.5 1.0

Nonpup Total 63.4 8.3

Grand Total 77.7 10.0
46

Table 4.2.--Composition of the Hawaiian monk seal population at

Lisianski Island during the spring and summer of

1996. Includes all pups born during the calendar

year.

Number of seals

Size Male Female Unknown Total

Sex ratio

male:female

Adults 78 50 0 128 1.6:1

Subadults 17 16 0 33 1.1:1

Juveniles 6 10 0 16 0.6:1

Pups 10 13 1a 24 0.8:1

Nonpup Total 101 76 0 177 1.3:1

Grand Total 111 89 1 201 1.2:1

a

One neonatal pup death.
47

Table 4.3.--Summary of tagged known-age seals born at Lisianski

Island and resighted there in 1996.

Age

(years) Sex

Number originally

tagged

Number resighted

in 1996

14 Male

Female

7

6

2

3

13 Male

Female

6

18

2

7

12 Male

Female

10

5

3

2

11 Male

Female

5

9

2

2

10 Male

Female

11

9

5

4

9 Male

Female

12

6

2

0

8 Male

Female

10

8

5

6

7 Male

Female

--

--

--

--

6 Male

Female

8

9

4

3

5 Male

Female

9

6

5

2

4 Male

Female

13

8

6

4

3 Male

Female

4

9

2

3

2 Male

Female

4

5

2

2

1 Male

Female

7

10

2

5
48

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

Island in 1996.

Event

Number of pups

Male Female Unknown Total

Born 10 13 1 24

Died prior to weaning 0 0 1 1

Still nursing 1 0 0 1

Weaned 9 13 0 22

Tagged 9 13 0 22

Table 4.4b.--Summary of nursing periods and measurements of

weaned pups at Lisianski Island in 1996. 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 37.2 102.8 124.8

St. Dev. 4.7 11.3 7.7

n 16 22 21
49

Table 4.5a.--Known movement of Hawaiian monk seals to Lisianski

Island from other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Original location Number, size, and sex class

Laysan Island 1 adult female,

3 subadult females

Pearl and Hermes Reef 1 subadult female

Table 4.5b.--Known movement of Hawaiian monk seals from Lisianski

Island to other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Destination Number, size, and sex class

French Frigate Shoals 1 subadult male

Laysan Island 4 adult females,

1 subadult female

Pearl and Hermes Reef 1 adult female,

1 subadult female
50

Table 4.6.--Factors affecting Hawaiian monk seal survival at

Lisianski Island in 1996.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Adult Male 1 1 0 0

Juvenile Female 1 1 0 0

Mounting by Male

Adult Female 2a 10 0

Entanglement

Subadult Female 1b 00 0

Weaned Pup Male 3b 00 0

Female 3c 00 0

Emaciation

Adult Male 1 0 0 1

Unknown

Adult Male 1 0 1d 0

Nursing Pup Unknown 1e 01 0 a

A mobbing event was observed involving five adult males with an

adult female who sustained no injuries.

b

Seal(s) released uninjured by observers.

c

One seal was entangled twice: once it disentangled itself and

the other time it was released by observers. The other seal was

released by observers. Both animals were uninjured.

d

Seal was lethargic and later found dead with severe shark

injuries. e

Decomposed carcass was found at the beginning of the season.
CHAPTER 5. THE HAWAIIAN MONK SEAL ON

PEARL AND HERMES REEF, 1996

Chad H. Yoshinaga, Irene T. Kinan, Allison C. Veit, and Christine

M. Vitulli

53

Pearl and Hermes Reef (lat. 27°55'N, long. 175°45'W) is one

of the major 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 non-vegetated sand islands

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 Reef in 1982. In

1996, research was conducted by NMFS during April 26-July 27.

The perimeters of the four larger vegetated islands were divided

into sectors using natural landmarks. Research objectives for

the Pearl and Hermes monk seal population in 1996 were to conduct

basic population research as outlined in Chapter 1, document all

births during the research period, and remove or destroy

hazardous marine debris from all haulout areas.

Censuses and Patrols

Atoll censuses (n = 8) were conducted every 5 days, on

average, during May 14-July 11, beginning at 1000 Hawaii standard

time and continuing for approximately 7 hours. All islands were

censused on foot by one or two persons. Patrols were conducted

opportunistically on noncensus days to resight seals tagged in

previous years.

Individual Identification

A total of 232 individuals (207 excluding pups) were

identified by existing or applied tags, bleach marks, scars, or

natural markings. All weaned pups (n = 23) were tagged with

Temple Tags and passive integrated transponder (PIT) tags. Two

immature female seals were also tagged with Temple Tags.

Collection of Samples

Forty-one scat and spew samples were collected. Tissue

samples were collected from nine seals during tagging. In total,

241 pieces of potentially entangling debris were inventoried and

destroyed, representing all of the potentially dangerous debris

present on beaches and haulout sites in 1996. Large amounts of

hazardous debris on offshore patch reefs and the outer barrier

reef could not be removed safely and were left in place.
54

RESULTS

Population Abundance and Composition

The means (±SD) for eight atoll censuses were 86.5 seals

(±12.9) including pups, and 72.5 seals (±13.4) excluding pups

(Table 5.1). The total spring-summer population was 223

individuals, 198 excluding pups (Table 5.2). The sex ratios of

nonpup immature seals and adults were 1.0:1 (37 males:37 females)

and 1.1:1 (63 males:57 females), respectively. The numbers of

tagged known-age seals born at Pearl and Hermes Reef during the

period from 1983 to 1996 and resighted there in 1996 are

summarized in Table 5.3.

Reproduction

At least 25 pups were born: 23 were weaned and 2 pups were

still nursing at the end of this study (Table 5.4a).

Measurements of weaned pups are summarized in Table 5.4b.

Twenty-five of fifty-seven (44%) adult-sized females were

parturient.

Interatoll Movement

Interatoll movement was documented for 19 seals that made a

total of 27 movements between Pearl and Hermes Reef and either

Lisianski, Midway, or Kure Atoll (Tables 5.5a and b).

Factors Affecting Survival

Entanglement and unknown factors led to four lifethreatening conditions (Table 5.6). Three weaned pups (two

males, one female) were entangled in marine debris, released by

observers, and resighted afterwards. No deaths were observed at

Pearl and Hermes reef in 1996.

ACKNOWLEDGMENTS

We thank the captain, officers, and crew of the NOAA Ship

Townsend Cromwell for their logistical support. We also

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

Hawaiian Islands National Wildlife Refuge staff.
TABLES
57

Table 5.1.--Summary statistics for atoll censuses ( n = 8) of the

Hawaiian monk seals at Pearl and Hermes Reef, from

May 14 to July 11, 1996.

Size/Sex

Mean number of

individuals

Standard

deviation

Adults 48.3 9.3

Male 17.5 2.9

Female 19.0 3.2

Unknown 11.8 5.6

Subadults 14.0 6.7

Male 7.0 4.3

Female 4.3 2.4

Unknown 2.8 1.2

Juveniles 10.1 2.9

Male 3.8 1.6

Female 4.6 2.4

Unknown 1.8 1.2

Pups 14.0 1.9

Male 5.6 1.9

Female 6.6 1.8

Unknown 1.8 1.2

Nonpup Total 72.5 13.4

Grand Total 86.5 12.9
58

Table 5.2.--Composition of the Hawaiian monk seal population at

Pearl and Hermes Reef during the spring and summer of

1996. Includes all pups born during the calendar

year.

Number of seals

Size Male Female Unknown Total

Sex ratio

male:female

Adults 63 57 3 123 1.1:1

Subadults 25 16 0 41 1.6:1

Juveniles 12 21 1 34 0.6:1

Pups 11 12 2 25 0.9:1

Nonpup Total 100 94 4 198 1.1:1

Grand Total 111 106 6 223 1.0:1
59

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

Hermes Reef and resighted there in 1996.

Age

(years) Sex

Number originally

tagged

Number resighted

in 1996

13 Male

Female

8

2

4

1

12 Male

Female

5

8

2

2

11 Male

Female

9

6

1

4

10 Male

Female

Unknown

10

7

1

4

3

0

9 Male

Female

14

7

7

2

8 Male

Female

12

6

10

2

7 Male

Female

8

6

5

3

6 Male

Female

5

1

3

0

5 Male

Female

10

11

8

5

4 Male

Female

13

10

9

7

3 Male

Female

14

7

6

5

2 Male

Female

--

--

--

--

1 Male

Female

16

11

12

7
60

Table 5.4a.--Summary of Hawaiian monk seals born at Pearl and

Hermes Reef in 1996.

Event

Number of pups

Male Female Unknown Total

Born 11 12 2 25

Died prior to weaning 0 0 0 0

Still nursing 0 0 2 2

Weaned 11 12 0 23

Tagged 11 12 0 23

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

Hermes Reef in 1996. All measurements were taken

within 2 weeks after weaning.

Axillary girth (cm)

Straight dorsal

length (cm)

Mean 107.6 129.6

St. Dev. 7.3 4.8

n 15 15
61

Table 5.5a.--Known movement of Hawaiian monk seals to Pearl and

Hermes Reef from other locations in 1996, summarized

by movements between two locations. No seals made

more than one trip.

Original location Number, size, and sex class

Lisianski Island 1 adult female,

1 subadult female

Midway Atoll 1 adult male,

4 adult females,

1 subadult male,

1 subadult female,

1 juvenile male

Kure Atoll 2 adult males,

1 subadult male

Table 5.5b.--Known movement of Hawaiian monk seals from Pearl and

Hermes Reef to other locations in 1996, summarized

by movements between two locations. No seals made

more than one trip.

Destination Number, size, and sex class

Lisianski Island 1 subadult female

Midway Atoll 3 adult males,

4 adult females,

1 subadult male,

1 subadult female,

1 juvenile male

Kure Atoll 1 adult male,

1 adult female,

1 subadult male
62

Table 5.6.--Factors affecting Hawaiian monk seal survival at

Pearl and Hermes Reef in 1996.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

(none observed)

Mounting by Male

(none observed)

Entanglement

Weaned Pup Male 2a 00 0

Weaned Pup Female 1a 00 0

Unknown

Adult Male 1 1 0 0

a

Seal(s) released uninjured by observers.
CHAPTER 6. THE HAWAIIAN MONK SEAL ON

MIDWAY ATOLL, 1996

L. L. Eberhardt, K. V. Eberhardt, and R. Lance Jeffery

65

Midway Atoll (lat. 28°15'N, long. 177°35'W) has

historically been one of the major haulout and pupping locations

of the endangered Hawaiian monk seal, although current population

levels and pup production are low. This atoll is located 2,100

km northwest of Oahu in the Northwestern Hawaiian Islands (Fig.

1.1) and comprises a circular fringing reef approximately 9 km in

diameter, enclosing a lagoon and three permanent islands (Sand,

Spit, and Eastern Islands) inside the southern part of the reef

(Fig. 6.1). Eastern and Spit Islands are uninhabited. Sand

Island was the site of a U.S. Naval Air Facility until 1993 when

the facility was closed. The Navy has vacated the atoll and

primary management authority has been transferred to the U.S.

Fish and Wildlife Service (USFWS), which has maintained a refuge

(Midway Atoll National Wildlife Refuge) at the site since 1988.

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). From the late 1960s to the

late 1980s the population failed to recover, but recent

assessments suggest that recovery may be beginning due to

immigrants from Kure Atoll and Pearl and Hermes Reef and an

increasing number of seals born on Midway Atoll. The earlier

counts indicate that the Midway population has significant

potential for growth, and recovery of this population is an

important management goal.

RESEARCH

Research was conducted by the National Marine Fisheries

Service during March 29-May 1 and July 30-August 1, 1996.

Incidental observations were recorded by USFWS personnel during

the rest of the year. The perimeters of the three permanent

islands were divided into sectors using artificial or natural

landmarks. Research objectives specific to this population in

1996 included the identification of all seals in the resident

population, estimation of the proportion identified using

sighting probability calculations, and tagging pups.

Censuses and Patrols

Atoll censuses (n = 11) were conducted every 2-3 days, on

average, from March 31 to April 26. All islands were censused on

foot by one or two persons. Each atoll census began between 0700

and 1400 Hawaii standard time, and ended between 0950 and 1650.

Beach counts of Sand Island (n = 10), Eastern Island (n = 1), or

Spit Island (n = 3) were conducted on non-atoll census days

during March 29-May 1 to identify and resight seals.

Individual Identification
66

A total of 45 individuals (38 excluding pups) were

identified by existing or applied tags, bleach marks, scars, or

natural markings. One juvenile seal was identified in January by

USFWS personnel, but was not subsequently resighted. Five weaned

pups were tagged with Temple Tags, and one of these same pups was

also tagged with passive integrated transponder (PIT) tags.

Collection of Samples

Tissue samples were collected from two seals during

tagging.

Special Studies

Sighting Probability Calculations

Probability calculations suggested that the 43 seals

identified during March 29-May 1 may have been virtually the

entire "population" using Midway Island at that time, but there

may have been one or two other seals undetected.

RESULTS

Population Abundance and Composition

The means (±SD) for eleven atoll censuses were 16.1 seals

(±3.5) including pups, and 12.7 seals (±3.3) excluding pups

(Table 6.1). The total spring-summer population was 42 seals, 35

excluding pups (Table 6.2). This total includes all seals

observed at Midway Island during March 29-May 1 (43 seals) plus

an additional nursing pup observed July 31, but minus two adult

females that pupped at Pearl and Hermes Reef in 1996 and are thus

included in the Pearl and Hermes population.

The estimation of population abundance is confounded by

movement of seals among Midway Atoll, Kure Atoll, and Pearl and

Hermes Reef. Because of the relatively short study period, it is

difficult to distinguish transient visitors from resident seals.

Further study of this population is needed to identify resident

seals and thereby provide a more reliable measure of abundance at

Midway Atoll.

The numbers of tagged known-age seals born at Midway during

the period from 1988 to 1995 and resighted there in 1996 are

summarized in Table 6.3.

Reproduction
67

At least seven pups were born: five weaned, the fate of one

was unknown, and one was still nursing at the end of this study

(Table 6.4). None of the weaned pups were measured within 2

weeks of weaning. Seven of sixteen (44%) adult-sized females

were parturient.

Interatoll Movement

Interatoll movement was documented for 21 seals that made a

total of 29 movements between Midway Atoll and either Kure Atoll

or Pearl and Hermes Reef (Tables 6.5a and b).

Factors Affecting Survival

Attacks by large sharks, entanglement, and unknown factors

led to five life-threatening conditions (Table 6.6). Three seals

were entangled and were released by observers. No deaths were

observed at Midway Atoll in 1996.

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife

Service, Midway Atoll National Wildlife Refuge. Special thanks

are extended to Nanette W. H. Seto, Biologist, and Kenneth R.

Niethammer, Refuge Manager. We also thank the officers and crew

of the NOAA ship Townsend Cromwell for logistical assistance.
TABLES
71

Table 6.1.--Summary statistics for atoll census ( n = 11) of

Hawaiian monk seals at Midway Atoll from March 31 to

April 26, 1996.

Size/Sex

Number of

individuals

Standard

deviation

Adults 9.0 3.0

Male 1.8 1.1

Female 7.2 2.6

Unknown 0.0 0.0

Subadults 1.0 1.0

Male 0.4 0.5

Female 0.6 0.7

Unknown 0.0 0.0

Juveniles 2.6 1.1

Male 1.7 0.6

Female 0.9 0.8

Unknown 0.0 0.0

Pups 3.4 1.3

Male 0.0 0.0

Female 0.8 0.4

Unknown 2.5 1.1

Nonpup Total 12.7 3.3

Grand Total 16.1 3.5
72

Table 6.2.--Composition of the Hawaiian monk seal population at

Midway Atoll during the spring and summer of 1996.

Number of seals

Size Male Female Unknown Total

Sex ratio

male:female

Adults 9 16 0 25 0.6:1

Subadults 1 4 0 5 0.2:1

Juveniles 3 2 0 5 1.5:1

Pups 2 4 1 7 1.0:1

Nonpup Total 13 22 0 35 0.6:1

Grand Total 16 25 1 42 0.6:1
73

Table 6.3.--Summary of tagged known-age seals born at Midway

Atoll and resighted there in 1996.

Age

(years) Sex

Number originally

tagged

Number resighted

in 1996

8 Male

Female

0

1

--

1

7 Male

Female

0

0

--

--

6 Male

Female

0

0

--

--

5 Male

Female

1

1

1

0

4 Male

Female

0

1

--

1

3 Male

Female

1

0

0

--

2 Male

Female

0

0 ----

1 Male

Female

Unknown

1

6

1

1

2

1
74

Table 6.4.--Summary of Hawaiian monk seals born at Midway Atoll

in 1996.

Event

Number of pups

Male Female Unknown Total

Born 2 4 1 7

Died prior to weaning 0 0 0 0

Still nursing 1 0 0 1

Weaning status unknown 0 0 1 1

Weaned 1 4 0 5

Tagged 1 4 0 5
75

Table 6.5a.--Known movement of Hawaiian monk seals to Midway

Atoll from other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Original location Number, size, and sex class

Pearl and Hermes Reef 3 adult males,

4 adult females,

1 subadult male,

1 subadult female,

1 juvenile male

Kure Atoll 1 adult male,

1 adult female

Table 6.5b.--Known movement of Hawaiian monk seals from Midway

Atoll to other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Destination Number, size, and sex class

Pearl and Hermes Reef 1 adult male,

4 adult females,

1 subadult male,

1 subadult female,

1 juvenile male

Kure 2 adult males,

6 adult females,

1 subadult male
76

Table 6.6.--Factors affecting Hawaiian monk seal survival at

Midway Atoll in 1996.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Juvenile Female 1 1 0 0

Mounting by Males

(none observed)

Entanglement

Weaned pup Unknown 1a 00 0

Immature Unknown 2a 00 0

Unknown

Adult Female 1 1 0 0

a

All entangled seals released by observers.
CHAPTER 7. THE HAWAIIAN MONK SEAL ON

KURE ATOLL, 1996

Lucy W. Keith, R. Lance Jeffery, and Jill D. Pettinger

79

Kure Atoll (lat. 28°25'N, long. 178°10'W) is one of the

major 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 Islets), and a sometimes emergent

area known locally as Stark Reef (Fig. 7.1). Until 1992, Green

Island was the site of a U.S. Coast Guard (USCG) LORAN station,

commissioned in 1961 and 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

removal of buildings and other structures on Green Island.

The Kure Atoll population of Hawaiian monk seals has been

growing in recent years due, 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-

91) 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, conditioning on Oahu, and then transport

to Kure Atoll for release. Continued monitoring of seals

involved in these projects is considered imperative to evaluate

the projects' long-term success.

RESEARCH

The National Marine Fisheries Service (NMFS) began research

on Hawaiian monk seals at Kure Atoll in 1981. In 1996, research

was conducted by NMFS during April 28-July 25. The perimeter of

Green Island was divided into eight sectors, using artificial or

natural landmarks. Research objectives for the Kure Atoll monk

seal population in 1996 are described in Chapter 1.

Censuses and Patrols

Atoll censuses (n = 15) were conducted approximately every

5 days, weather permitting, from May 11 to July 25. Each census

began at 1300 Hawaii standard time and ended between 1400 and

1900. All islands were censused on foot by one or two persons.

Stark Reef was not included in any atoll census or patrol.

Patrols were conducted to identify seals and monitor locations

used by parturient females.

Individual Identification

A total of 117 individuals (100 excluding pups) were

identified by existing or applied tags, bleach marks, scars, or
80

natural markings. All weaned pups (n = 16) were tagged with

Temple Tags, and passive integrated transponder (PIT) tags.

Collection of Samples

Ninety-five scat and spew samples were collected. Tissue

samples were collected from 16 weaned pups during tagging. In

total, 844 pieces of potentially entangling debris were

inventoried; 4 entanglement items were removed from seals and

collected; the remainder was destroyed before the end of the

field season.

RESULTS

Population Abundance and Composition

The means (±SD) for 15 atoll censuses were 46.7 seals

(±9.0) including pups, and 38.5 seals (±7.7) excluding pups

(Table 7.1). The total spring-summer population included 35

adult females and 56 immature individuals (subadults, juveniles,

and pups), of which 39 were subadults or juveniles (Table 7.2).

Although the total number of adult males was not obtained due to

our inability to identify all individuals, it is estimated that

only a small, but unknown, number was not identified. The

numbers of tagged known-age seals born at Kure Atoll during the

period from 1981 to 1995 and resighted there in 1996 are

summarized in Table 7.3.

Reproduction

At least 17 pups were born: 16 were weaned and 1 died

prior to weaning (Table 7.4a). Seven pups were known to have

weaned less then 2 weeks prior to being tagged, and their

measurements are summarized in Table 7.4b. Of the 35 adult-sized

females identified in the spring-summer population, a minimum of

17 were parturient (49%). Because eight pups weaned before field

observations commenced in April, only nine parturient females

were identified. Five of these nine females had been temporarily

maintained as pups in the Kure Atoll Head Start enclosure (one in

1982, one in 1984, two in 1985, and one in 1988) and two others

were rehabilitated seals from FFS introduced to Kure as yearlings

via the Head Start enclosure.

Interatoll Movement

Interatoll movement was documented for 16 seals that made a

total of 17 movements between Kure Atoll and either Midway Atoll

or Pearl and Hermes Reef (Table 7.5a and b).
81

Factors Affecting Survival

Attacks by large sharks and entanglement in debris led to

eight life-threatening conditions which resulted in the confirmed

deaths of two animals and the probable death of another seal

(Table 7.6). A subadult female from FFS, rehabilitated and

released at Kure in 1995, died as a result of a shark bite wound

to the ventrum. A male weaned pup was sighted with a large

gaping shark bite wound covering most of his right side; the pup

subsequently disappeared. Four entanglements were observed: an

adult female from FFS, rehabilitated and released at Kure in

1991, and two male weaned pups were seen entangled, and

subsequently released by observers. One of these pups was

observed entangled, and then released on two separate occasions.

ACKNOWLEDGMENTS

We acknowledge the officers and crew of the NOAA ship

Townsend Cromwell for logistical support and for transport to and

from Kure Atoll. We also thank the State of Hawaii Division of

Forestry and Wildlife and the U.S. Coast Guard cutter Washington

for logistical support.
TABLES
85

Table 7.1.--Summary statistics for atoll censuses ( n = 15) of

Hawaiian monk seals at Kure Atoll from May 11 to

July 25, 1996.

Size/Sex

Mean number of

individuals

Standard

deviation

Adults 21.1 5.2

Male 6.3 2.1

Female 11.4 3.2

Unknown 3.4 1.6

Subadults 14.3 3.7

Male 6.1 2.8

Female 6.5 1.4

Unknown 1.7 1.2

Juveniles 2.9 1.2

Male 0.9 1.0

Female 1.3 0.7

Unknown 0.7 0.8

Pups 8.2 3.1

Male 5.3 1.5

Female 2.3 1.8

Unknown 0.7 0.9

Nonpup Total 38.5 7.7

Grand Total 46.7 9.0
86

Table 7.2.--Composition of the Hawaiian monk seal population at

Kure Atoll during the spring and summer of 1996.

Includes all pups born during the calendar year.

Number of seals

Size Male Female Unknown Total

Sex ratio

male:female

Adults 24a 35 0 59a 0.7:1

Subadults 14 16 0 30 0.9:1

Juveniles 4 4 1 9 1.0:1

Pups 10 7 0 17 1.4:1

Nonpup Total 42a 55 1 98a 0.8:1

Grand Total 52a 62 1 115a 0.8:1 a

A small, but unknown, number of adult males remained

unidentified at the end of the field season.
87

Table 7.3.--Summary of tagged known-age seals born at Kure Atoll

and resighted there in 1996.

Age

(years) Sex

Number originally

tagged

Number resighted

in 1996

15 Male

Female

3

5

2

1

14 Male

Female

1

3

0

2

13 Male

Female

4

0

2

--

12 Male

Female

4

2

1

2

11 Male

Female

2

3

1

3

10 Male

Female

1

0

1

--

9 Male

Female

1

3

1

2

8 Male

Female

2

5

2

2

7 Male

Female

5

4

2

1

6 Male

Female

3

3

0

2

5 Male

Female

7

6

4

3

4 Male

Female

5

8

3

5

3 Male

Female

9

4

5

2

2 Male

Female

3

0

0

--

1 Male

Female

6

5

4

4
88

Table 7.4a.--Summary of Hawaiian monk seals born at Kure Atoll in

1996.

Event

Number of pups

Male Female Unknown Total

Born 10 7 0 17

Died prior to weaning 0 1 0 1

Weaned 10 6 0 16

Tagged 10 6 0 16

Table 7.4b.--Summary of nursing periods and measurements of

weaned pups at Kure Atoll in 1996. 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 33.8 102.6 124.6

St. Dev. 3.5 9.0 8.0

n 377
89

Table 7.5a.--Known movement of Hawaiian monk seals to Kure Atoll

from other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Original location Number, size, and sex class

Pearl and Hermes Reef 1 adult male,

1 adult female,

1 subadult male

Midway Atoll 2 adult males,

6 adult females,

1 subadult male

Table 7.5b.--Known movement of Hawaiian monk seals from Kure

Atoll to other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Destination Number, size, and sex class

Pearl and Hermes Reef 2 adult males,

1 subadult male

Midway Atoll 1 adult male,

1 adult female
90

Table 7.6.--Factors affecting Hawaiian monk seal survival at

Kure Atoll in 1996.

Outcome

Size Sex Total Injured Died Probably died

Attack by Large Shark

Subadult Male 1 1 0 0

Subadult Female 1 0 1 0

Weaned pup Male 1 1 0 1

Mounting by Males

(none observed)

Entanglement

Adult Female 1a 00 0

Weaned pup Male 3a 00 0

Unknown

Nursing pup Female 1 0 1 0

a

All entangled seals released by observers.
CHAPTER 8. THE HAWAIIAN MONK SEAL ON

NIHOA AND NECKER ISLANDS AND GARDNER PINNACLES, 1996

Brenda L. Becker, Mitchell P. Craig, Chad Yoshinaga,

Craig Rowland, Joy A. Seymour, and Suzanne Russell

93

Nihoa Island (lat. 23°04'N, long. 161°55'W), Necker Island

(lat. 23°36'N, long. 164°42'W), and Gardner Pinnacles (lat.

25°00N, long. 167°55W) are located ca. 450, 750, and 850 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, pup production is limited by lack

of haulout area.

RESEARCH

In 1996, data were collected by the U.S. Fish and Wildlife

Service at Nihoa Island during July 9-26. The National Marine

Fisheries Service collected data at Necker Island on April 19 and

August 4 and at Gardner Pinnacles on August 2. The perimeters of

Nihoa and Necker Islands were divided into 3 and 10 sectors,

respectively, using natural landmarks (Fig. 8.1). Gardner

Pinnacles was considered 1 sector. Beginning in 1989, the monk

seal population at French Frigate Shoals began to decline,

largely from poor survival of juvenile seals. In 1996, research

objectives specific to the Nihoa and Necker Islands and Gardner

Pinnacles monk seal populations included assessment of the extent

of migration from French Frigate Shoals to these locations to

determine if migration may have contributed to the decline

observed at French Frigate Shoals.

Censuses and Patrols

Three counts were conducted on Nihoa Island by one observer

during different times of the day for approximately .2 to 1.4

hours. Incidental sightings were also conducted

opportunistically to read tags previously applied to seals.

One census was conducted on Necker Island by one observer

on April 19, beginning at 1000 Hawaii standard time and

continuing for approximately 5 hours. One incidental patrol was

conducted on August 4 to read tags previously applied to seals.

Data from satellite-tagged seals also provided sighting data at

Necker Island.

One census was conducted at Gardner Pinnacles by one

observer on August 2, beginning at 1715 Hawaii standard time and

continuing for .9 hour.

Individual Identification

On Nihoa Island, two seals were identified by existing

tags: one unknown-aged male seal tagged on Laysan Island that

later translocated to the main Hawaiian Islands in 1994, and one

female tagged at French Frigate Shoals.
94

On Necker Island, eight seals (four males, four females)

were identified by existing tags applied at French Frigate

Shoals, including a 2-year-old female, two 7-year-old males, a 9-

year-old male a 9-year-old female, a 12-year-old male, and two

12-year-old females. Four of these animals had been seen at

French Frigate Shoals in 1995. It is unlikely that migration to

Necker Island was the reason for the recent decline of juvenile

seals at French Frigate Shoals as only one tagged seal was

immature and 96% of the seals present during the census were

adults.

On Gardner Pinnacles, four male seals were identified by

tags or satellite tag transmissions, including an adult of

unknown age, a 10-year-old, an 11-year-old, and a 12-year-old.

Collection of Samples

No samples were collected.

RESULTS

Population Abundance and Composition

The means (±SD) for three counts conducted on Nihoa Island

were 20 seals (±4.4) including pups, and 18 seals (±3.5)

excluding pups. Because of limited effort, the composition of

the spring-summer population was not determined.

The census total conducted on Necker Island was 28 seals;

no pups were observed. Because of limited effort, the

composition of the spring-summer population was not determined.

The Gardner Pinnacles census total was three seals; no pups

were observed. Because of limited haulout space on sloping rocks

at low tide, there may not be a resident population present.

Reproduction

In 1996, at least three pups (all nursing) were born on

Nihoa Island and at least two pups (one weaned male and one

nursing female) were born on Necker Island. No pups were sighted

at Gardner Pinnacles.

Interatoll Movement

Interatoll movement was documented for three seals that

made a total of three movements between Nihoa Island and the main

Hawaiian Islands and French Frigate Shoals (Tables 8.1a and b).

Interatoll movement was documented for eight seals that made a

total of 12 movements between Necker Island and French Frigate

Shoals (Tables 8.1c and d). In 1996, three of the adult females

sighted at Necker Island subsequently moved to French Frigate
95

Shoals where they pupped. Four seals made a total of six trips

between Gardner Pinnacles and French Frigate Shoals (Tables 8.1e

and f).

Factors Affecting Survival

One female on Nihoa Island received a potentially lifethreatening injury, probably caused by a cookie cutter shark, and

survived. Factors affecting survival were not observed on Necker

Island or Gardner Pinnacles in 1996.

ACKNOWLEDGMENTS

We acknowledge the support of the U.S. Fish and Wildlife

Service, Hawaiian Islands National Wildlife Refuge staff, and the

captain, officers, and crew of the NOAA ship Townsend Cromwell, R/V Machias, and the U.S. Coast Guard Vessel Washington for

logistical assistance.
TABLES
99

Table 8.1a.--Known movement of Hawaiian monk seals to Nihoa

Island from other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Original location Number, size, and sex class

Main Hawaiian Islands 1 adult male

Table 8.1b.--Known movement of Hawaiian monk seals from Nihoa

Island to other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Destination Number, size, and sex class

French Frigate Shoals 1 adult male,

1 adult female
100

Table 8.1c.--Known movement of Hawaiian monk seals to Necker

Island from other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Original location Number, size, and sex class

French Frigate Shoals 4 adult males,

3 adult females,

1 subadult female

Table 8.1d.--Known movement of Hawaiian monk seals from Necker

Island to other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Destination Number, size, and sex class

French Frigate Shoals 1 adult male,

3 adult females
101

Table 8.1e.--Known movement of Hawaiian monk seals to Gardner

Pinnacles from other locations in 1996, summarized

by movements between two locations. No seals made

more than one trip.

Original location Number, size, and sex class

French Frigate Shoals 4 adult males

Table 8.1f.--Known movement of Hawaiian monk seals from Necker

Island to other locations in 1996, summarized by

movements between two locations. No seals made more

than one trip.

Destination Number, size, and sex class

French Frigate Shoals 2 adult males
REFERENCES
105

Alcorn, D. J.

1984. The Hawaiian monk seal on Laysan Island: 1982. U.S.

Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFC-42, 37

p.

American Society of Mammalogists, Committee on Marine Mammals.

1967. Standard Measurements of Seals. J. Mammal. 48:459-

462.

Boness, D. J.

1990. Fostering behavior in Hawaiian monk seals: is there a

reproductive cost? Behav. Ecol. Sociobiol. 27:113-122.

Cleveland, W. S.

1979. Robust locally weighted regression and smoothing

scatterplots. J. Amer. Stat. Assoc. 74:829-836.

Gilmartin, W. G. and T. Gerrodette.

1986. Hawaiian monk seal status and recovery potential at

Kure Atoll. Honolulu Lab., Southwest Fish. Cent., Natl.

Mar. Fish. Serv., NOAA, Honolulu, HI 96822-2396, Southwest

Fish. Cent. Admin. Rep. H-86-16, 26 p.

Gilmartin, W. G., R. J. Morrow, and A. M. Houtman.

1986. Hawaiian monk seal observations and captive

maintenance project at Kure Atoll, 1981. U.S. Dep.

Commer., NOAA Tech. Memo., NOAA-TM-NMFS-SWFC-59, 9 p.

Hiruki, L. M., Gilmartin, W. G., Becker, B. L., and Stirling, I.

1993. Wounding in Hawaiian monk seals ( Monachus

schauinslandi). Can. J. Zool. 71:458-468.

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.

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.

Kenyon, K. W.

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.

Jague-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. Commer., NOAA Tech. Memo. NOAATM-NMFS-SWFC-47, 33 p.

Winchell, J.

1990. Field manual for phocid necropsies (specifically

Monachus schauinslandi). U.S. Dep. Commer., NOAA Tech.

Memo. NOAA-TM-NMFS-SWFSC-146, 55 p.
APPENDIXES
109

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 T. J. Ragen (Eds.).

1997. The Hawaiian monk seal in the Northwestern Hawaiian

Islands, 1995. U.S. Dep. Commer., NOAA Tech. Memo., NOAATM-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., NOAATM-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., NOAATM-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., NOAATM-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.

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-TMNMFS-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-TMNMFS-SWFSC-178, 83 p.

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. NOAATM-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. NOAATM-NMFS-SWFSC-177, 61 p.
Appendix A.--Continued.

110

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. NOAATM-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-TMNMFS-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.

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-TM-NMFS-SWFC-118, 38

p.
Appendix A.--Continued.

111

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-SWFSC151, 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-TMNMFS-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-NMFSSWFSC-179, 33 p.
Appendix A.--Continued.

112

Stone, H. S.

1984. Hawaiian monk seal population research, Lisianski

Island, 1982. U.S. Dep. Commer., NOAA Tech. Memo. NOAATM-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 Reef

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 1992. 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.
Appendix A.--Continued.

113

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.

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. NOAATM-NMFS-SWFC-55, 11 p.
115

Appendix B.--Hawaiian monk seal census form and 1996 census form

directions.

(See following pages.)


119

1996

CENSUS FORM DIRECTIONS

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).

A = Atoll-wide census (must be completed within 2 days)

B = Behavior patrol: A complete, untimed count where size, sex,

ID, and disturbance are recorded. Associations are coded if

they involve adult or subadult seals (Laysan and Lisianski

Islands only in 1996).

P = Patrol: A complete, untimed count where size, sex, ID, and

disturbance are recorded.

I = Incidental observ. (limit these, FWS data, etc).

T = Tag status entry for non-active tags (tags not currently on

a seal). Record tag status in notes columns.)

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 needed for

data retrieval.

PAGE Page number within a census or patrol. For example, if the census

(or patrol) requires three pages, then mark the first page as "page 1

of 3" and so on. If more than one person conducts 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.

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-hour clock, e.g., 6 p.m. = 1800, for the group

of pages.

DATE The date that data are collected (in YYMMDD format).

NUMBER Censuses, Atoll counts, Behavior patrols, and Patrols must be

numbered. Each data type will have its own three-digit number

series, starting with 001.

TEMP. Temperature in degrees Celsius at beginning of census or patrol.

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: 00 = no clouds

01-09 = 10 to 90% cover

10 = 100% cover

PREC. Precipitation: 0 = no precipitation or trace

1 = mist/drizzle

2 = rain

3 = intermittent rain

CONTINUE If the same seal sighting is recorded on several lines for any

reason (e.g., additional tag or association, behavior at a later
120

time, change of beach position), put the original line number you

are continuing from here. Lines may be continued only within the

same page. All fields from SECTOR through MOLT will be copied

from the original line if left blank on the continuation line.

Several lines can have the same continuation line number.

TIME The time should be recorded for each seal sighting, on a 24-hour

clock

SECTOR Location on island (e.g., 1-20 on Laysan)

Special codes as follows:

00 = unknown sector

77 = pen

88 = offshore spit

99 = island not present

SIZE Size is estimated using a classification scheme from Stone (1984), using

the following terminology:

Juvenile Sort, slight seals from the length of a weaned pup (about

138 cm) to 20-30 cm longer, including yearlings, and perhaps

younger seals, up to perhaps 3 years. Distinguished from

pups by thinness and pelage color.

Subadults Seals perceptibly longer than juveniles up to breeding size;

less robust than adults, generally with lighter pelage.

Immature seals likely from 3 or 4 to 5 or 6 years.

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 venter, and extensively

scarred.

Code size as follows

Nursing pups

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 <90 cm girth)

W = Weaned pup

Immatures

I = Immature

J = Juvenile

J1 = Juvenile I

J2 = Juvenile II

S = Subadult

S3 = Subadult III

S4 = Subadult IV

Adults

A = Adult

Unknowns

U = Seal of unknown size

Turtles
121

T = Turtle

T1 = Turtle, juvenile (<65 cm)

T2 = Turtle, subadult (65-80 cm)

T3 = Turtle, adult (>80 cm)

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 beach). When recording malemale interactions (at Laysan and Lisianski Islands in 1996), make

a continuation line previous to the original line to indicate that

the seal changed beach position before you come abreast of it.

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

9 = on an offshore rock (not included in census tally)

X = data not taken

CONDITION It is assumed that condition is recorded for all seals (except

nursing pups) on census or atoll count. Always record the

condition of the mom and pup on their first sighting post-partum

and post-weaning, regardless of data type. Always note condition

when recording a survival factor.

Condition codes:

M = medium

P = probably pregnant

F = fat

T = thin

X = data not taken

If the condition code is left blank, condition is assumed to be

medium.

ID DATA These fields can be used to record either a temporary or permanent

ID number. Use continuation lines to record both a temporary and

permanent number, or two temporary numbers.

T/P Indicate whether the number in the subsequent field is a temporary or

permanent ID number.

T = temporary ID number (or bleach number)

P = permanent ID number

TEMPORARY ID NO. Record the temporary ID number (or bleach number) of seal if

known; right justified. This 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-).
122

? column:

0 = seal is definitely unmarked; can coexist with a temporary

number, or with a bleach number if bleach hasn't taken yet

or the number has molted off

1 = bleach is present, but the number is questionable

4 = partially read bleach number completed 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, use for data

types C, A, B, or P (for unident. cruisers moving ahead of

you on census, etc.).

blank = number is certain and complete if present

PERMANENT ID NO. Record the four-digit permanent ID number of seal if known

(put both the island-specific prefix and next digit in the

first box provided).

? column:

0 = seal is definitely not an IDed animal

1 = ID number is questionable

blank = ID number is certain and complete if present

TAG NO. Tag number if known; right justified. If a number is

incompletely read, use dashes as place-holders 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). Record the last

five digits of a 10-digit PIT tag (put all 10 digits in the

notes).

L/R: Tag position

L = tag on left flipper

R = tag on right flipper

B = tags on both flippers (enter one tag number)

COL:

Color code -see the Tag Sample Kit if unsure of the colors

Temple tags Other tag types

Y = yellow (FFS) M = metal, Monel

T = tan/brown (Laysan) P = plastic, Riese

G = green (Lisianski) C = clear, PIT tag

B = blue (Pearl & Hermes)

K = silver/gray (Kure)

R = red (Midway, Necker, Nihoa, Main Islands)

? column:

0 = seal is definitely not tagged

1 = seal is tagged, but the number is questionable

4 = partially read tag completed from other data

5 = incompletely read tag, but partial data are certain (if seal

can't be identified by ID or Temporary #)

8 = Tag lost/unreadable. Fill out tag position (L/R) and the

tag condition event with codes L or U. Complete the tag

number and color from other data before entry.

blank = tag information is certain if present. Partial data

(either 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 computer

will only fill blank fields, so an incomplete Tag #
123

must be completed by hand (use a "4" in the tag ?

column).

MOLT Percentage of old pelage lost, optional for nursing pups

blank = no molting evident

0-9 = 1 to 99% molted:

0 = molting, but less than 10%; 1 = 10-19%; ... 9 =

90-99%. The first record of a >2 molt is considered

the first day of true molt.

10 = 100% molted, freshly molted, required for the first

month after molt. Put both digits of the 10 in the

single box provided.

? column:

0 = seal is definitely not molting

1 = seal is molting, but % molt estimate is questionable. May

or may not include an estimate in the molt column

DISTURB The degree to which the seal may have been disturbed by

observer

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 Use continuation lines to record more than one

association. Don't record associations involving

turtles. Record detailed association data at Laysan and

Lisianski Islands in 1996. At other locations, record

mother-pup pairs and unusual events. At all locations

except Laysan and Lisianski Islands, the X code will be

filled in by computer to indicate that standard

association data was not recorded on Census or Atoll

Count.

Active associations

1) noted for all except behaviors between mother and nursing pup

2) must take place within 30 m of observer

3) subjects may be any distance 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 in straight line of sight, can be on opposite

sides of a log.

LINE NO. Identity of the other seal in the association. Put its line

number here (note line number refers to within same census page

only).

DIST. Closest distance during behavior

0 = body contact
124

1 = <2 m

2 = 2-5 m

3 = >5 m (>5 m but <10 m in the case of L behavior code)

BEHAVIOR Up to four behaviors may be recorded for each association, but N,

X, and O should not appear together with other behaviors.

Behaviors B and M require distance = 0. With the exception of

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).

1) individual seal

a) active behavior

A = approach/investigate/sniff/nudge

B = bite

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

F1 = flee/move away, <2 body lengths

F2 = flee/move away, >2 body lengths move away

J = joust

J1 = joust <30 s*

J2 = joust >30 s* spar/fight*

M = mount/attempted

M1 = mount/attempted mount <30 s

M2 = mount/attempted mount >30 s

P = play*

R = submissive roll/present 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.

L = association by location only (distance <10 m apart, for

all except mother-pup pairs)

c) optional codes

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 before and after contest if

displacement occurs.

Q = loser*

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.

* 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
125

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 continuation lines.

A = artwork (scars drawn)

B = birth, 1st sighting post-partum (mom and pup)

G = seal is green with algae

H = handwritten notes

M = marked, bleach number 1st applied/reapplied post-molt

W = weaning, 1st sighting postweaning (pup)

X = pup exchange, 1st sighting after exchange (mom and pup)

Y = disturbance is to "bystander" seal during non-survey activity such

as tagging.

FOR DATA TYPE "T", STATUS OF NON-ACTIVE TAGS:

F = found

R = recovered from seal in hand

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 coding:

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.

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 than one applies.

D = death

W = wound

E = entanglement

V = very thin (emaciated)

I = illness/abnormal

M = mobbing/harassment

O = other

5 Participant type (for mobbings/
126

harassments 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.

1 Handling type

T = tagging (w/ restraint)

M = measuring (includes weighing)

A = all (both tagging and

measuring)

R = remote tagging

D = disentangle

I = instrument

B = bleeding

C = take into captivity

F = free from captivity

O = other

TYPE CODES CONTENT

COLUMN

P = photo RECORD IMPORTANT DESCRIPTIONS AND ANY

NON-SEAL PHOTOS IN HANDWRITTEN NOTES,

AND TRANSFER TO THE PHOTO COMMENT 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
127

H = head

A = anterior body (neck and

shoulders)

M = midbody (behind foreflippers

and before posterior)

P = posterior body (behind midbody

and before rear flippers)

F = foreflipper; write whether

dorsal/ventral in comments

R = rearflipper; write whether

dorsal/ventral in comments

O = overall view of a particular

side

X = other, describe in comments

8 Purpos

e

I =

iden

tifi

cati

on

F = survival factor (link with

survival factor EVENT using

continuation lines)

X = other, describe in comments

TYPE CODES CONTENT

COLUMN

T = tag condition RECORD HERE FOR ACTIVE TAGS (TAGS ON

SEALS) ONLY

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

Riese and 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
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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 but get no

reading. Combine the L or U codes with

the tag questionable code of 8. 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

Additional notes:

1. All original monk seal 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 running 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 computer 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.

2. A separate data sheet should 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 present, indicate this by using 99 for the sector

code, leaving the rest of the (first) line blank. To save paper, you

should use a census form with multiple headers if you only have a few

seals to record (i.e., at some islands within an atoll, or when

recording incidental sightings before or after census or patrol). In

essence, on a census form with multiple headers, each header and its

associated lines represents a separate data sheet.

3. 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. Patrol observers should

attempt to start at roughly the same time. The sum of all observers'

patrol activities for a day should result in one complete island count.

4. 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.

5. 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. If the

seal is identified, it will not be counted twice on census. To link two

sightings of 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.
129

6. Only code the sex as known if the ventral is seen or if the seal is the

mother in a mother/pup pair, even if you "know" the sex because of the

tag, bleach, scars, or behavior.

7. Record all tag sightings explicitly (i.e., both left and right tag

numbers) at least once during your stay. When a pup is tagged, record

the animal handling event on the census data sheet, and record detailed

information (such as all tag numbers) on a Tagging/Handling 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.

8. Be sure to code the original tag color, not the color that a tag has

faded to. See the Tag Sample Kit in the Bible.

Original tag color: Faded tag may appear:

Temple Tags:

Light Tan (A,T,K,L series @ Laysan)..........Gray, Lt. Yellow, White

Dark Tan/Brown (later series @ Laysan).......Red

Gray (A,T,K,L,N,F,U,G series @ Kure).........Light Tan

Silver Gray (600-900,0,Z and later @ Kure)...Metal

Red..........................................Orange

Yellow.......................................White, Lt. Yellow

Green (dark forest)..........................Dark Blue, Navy

Blue (light).................................--

Riese Tags (colors almost completely faded-just note presence if you can

ID by other means):

White........................................Yellow

Red..........................................Orange

Orange.......................................Red

Yellow.......................................White

Green........................................Blue

Blue.........................................Green

9. Always record disturbance. 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. At locations other

than Laysan and Lisianski Islands, it is not assumed that association

data will be taken on census or atoll count in 1996. Thus, on a census

or atoll count sheet from these other locations, no code in any of the

association columns means that data was not taken, and an X code will be

filled in by computer. If you wish to indicate that a seal was alone,

use the O behavior code. At Laysan and Lisianski Islands in 1996, it is

assumed that behavioral data will be taken on census (and during

behavior patrol). Thus, on a census or behavior patrol data sheet from

Laysan or Lisianski Island, no code in any of the association columns

means that the seal was alone, whereas on a regular patrol data sheet

from the same location, 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.

10. 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

record behaviors of an animal after it has been disturbed by the

observer.
130

11. All associations should be in pairs, i.e., between animals on two

different lines. If the behavior is active, you should fill in the line

numbers, distances, and behavior codes for both animals involved in the

association. If the behavior is N or L, however, you may record the

association on only one of the lines, and the entry/checking program

will fill in the other line. When recording an active behavior that

requires a corresponding code, 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).

12. 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 so that you will be aware, and

can record, if a specific tag breaks or is lost during the field season.

13. Do not make up additional codes. If the need for an additional code

arises, contact Honolulu.
131

CONTEST RULES

1. Size class collapse for contests: all subadults = adults (both sexes)

2. Definition of pair type (depends 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 contest (must conform to at least one 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 adult male:

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 with

Juvenile if has D

ii)

Original Male

Paired with Adult

Female otherwise

Has F No Ties

No Ties

Paired Male vs. Paired Male

where both 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