bluuebunny/crossref_metadata_2025 huggingface dataset:
THE NEGOTIATION OF SPACE AMONG SEX WORKERS IN CEBU CITY, THE PHILIPPINES
Authors: McIlwaine Cathy
Published: August 2006

The paper examines the experiences of space among sex workers in Cebu City, a major service and commercial centre in the Visayan region of the Philippines. It explores the issue of space from a number of perspectives and scales: first, at the national level in terms of migration patterns among sex workers; second, at the local level in relation to how sex workers experience and construct urban spaces through residence and working patterns; and finally, from a community perspective, the nature of domestic spaces among these women. The underlying theme of the paper centres around the contradictory ways in which social opprobrium is often reflected in spatial seclusion among sex workers. On the one hand, they are constrained in their experiences of space. On the other, the construction of their own particular spaces reflects a high degree of resourcefulness and resistance. This is corroborated further by the fact that involvement in the sex industry creates a different set of spatial aspirations and awareness among sex workers compared with those of the wider population.
NEGOTIATING DUALISMS: WOMEN, LOCALITY AND EMPLOYMENT OPPORTUNITIES IN OAXACA CITY, MEXICO
Authors: Willis Katie D.
Published: August 2006

This paper examines the validity of the public/private and reproductive/productive dichotomies commonly adopted in the analysis of gender and employment. It considers three aspects of the dualisms: spatial division, activity patterns and the construction of identities. The discussion is based on fieldwork undertaken in three districts of Oaxaca City, Mexico, between 1992 and 1995. While recognising the usefulness of spatial dualisms within Mexican cities, the paper seeks to identify the ways in which class and location within the urban space affect the construction of the boundary between “public” and “private”, women's “employment” experiences, and women's identities.
EVOLUTION, TAXONOMY AND ANTITROPICAL DISTRIBUTIONS OF THE PORPOISES (PHOCOENIDAE, MAMMALIA)
Authors: Barnes Lawrence G.
Published: August 2006

Abstract

True porpoises are a morphologically distinctive and evolutionarily old group of odontocete cetaceans classified as the family Phocoenidae. They are distinct from members of the family Delphinidae, with which they have sometimes been classified. Re‐examination of all living and fossil species of phocoenids yields new information on the evolution of the family and indicates the need for significant taxonomic changes. Two separate lines of descent within the group are classified as the subfamilies Phocoeninae and Phocoenoidinae. The living southern hemisphere spectacled porpoise, Phocoena dioptrica, is actually more closely related to the North Pacific Dali's porpoise, Phocoenoides dalli, than to other species of Phocoena. It therefore belongs in the subfamily Phocoenoidinae with Phocoenoides but represents a separate genus, Australophocaena (new genus). The earliest unquestioned fossil phocoenids have been found only in rocks around the Pacific basin. They include latest Miocene and Pliocene species of Piscolithax and the Late Miocene Salumiphocaena stocktoni (new genus) in the Phocoenoidinae, and an undescribed latest Miocene species in the Phocoeninae. World climate has influenced past and present distributions of phocoenids, and Australopbocaena dioptrica is possibly the antitropical counterpart of Phocoenoides dalli. All species of living phocoenids show similarities caused by convergent evolution, resulting in part from the phenomenon of paedomorphosis.
PHYSIOLOGY WITHOUT RESTRAINT IN DIVING MAMMALS
Authors: Kooyman Gerald L.
Published: August 2006

Abstract

Forced submersions and natural dives are compared with regard to heart rate, blood distribution and O2 consumption. Heart rate has been used as a primary indicator of blood distribution. However, often the dive heart rate has been compared to inappropriate surface conditions, and it is suggested that it should be compared to resting apneusis in the arrhythmic breathing animal. Furthermore, natural dives are frequently short relative to the breathhold capacity of a diver, and often during these dives there is little change in heart rate or apparent kidney function from the resting state. Calculations are made to determine the breathhold limit without O2 conservation measures. Further calculations are made to estimate the expected metabolism and metabolite production during an exceptionally long dive in a seal when O2 conservation must be invoked. These results are compared to known values obtained from a Weddell seal that made a 61 min dive. Based on the results of these observations and calculations, three possible models of blood distribution during natural dives are discussed. This discussion shows the limitation of present data and the type of data needed to resolve the question of how aquatic vertebrates manage O2 stores during dives of varying durations.
RADIOTAGGING STUDIES OF BELUKHA WHALES (DELPHINAPTERUS LEUCAS) IN BRISTOL BAY, ALASKA
Authors: Frost Kathryn J. , Lowry Lloyd F. , Nelson Robert R.
Published: August 2006

Abstract

Research was conducted in Bristol Bay, Alaska, to determine the applicability of radiotagging to studies of behavior, distribution and movements of belukha whales. Backpack‐style VHF transmitters were attached to two belukhas by pinning through the dorsal ridge. Both packages were shed after about 2 wk due to migration of the pin through the tissue. Movements of radio‐tagged whales were essentially local within Kvichak Bay. Three basic respiration patterns were identified: surfacings that were grouped into breathing periods separated by longer dives; surfacings that did not occur during restricted breathing periods; and long‐to‐very‐long surfacings separated by short‐to‐very‐short dives. These patterns were interpreted as representing traveling, feeding and feeding or resting in very shallow water. Surface and dive interval data were used to calculate a correction factor of 2.75, which could then be applied to aerial survey counts to estimate the total number of belukha whales in the study area. Modifications to radio packages are necessary in order to increase retention time.
FORCE AND BENDING MOMENT OF THE CAUDAL MUSCLES IN THE SHORTFIN PILOT WHALE
Authors: Arkowitz Robert , Rommel Sentiel
Published: August 2006

Abstract

Controversy has existed about the power stroke of cetacean locomotion. We therefore measured cross‐sectional areas of the appropriate muscles of the tail and computed possible forces and bending moments. The muscle areas are approximately equal in size and a similar relationship holds for the caudal tendons. It appears that the hypoaxial and epiaxial muscles are capable of generating forces that are approximately equal. Thrust delivered in the upstroke and downstroke may therefore be equal.
REPRODUCTIVE MATURITY AND SEASONALITY OF MALE SPOTTED DOLPHINS, STENELLA ATTENUATA, IN THE EASTERN TROPICAL PACIFIC
Authors: Hohn Aleta A. , Chivers Susan J. , Barlow Jay
Published: August 2006

Abstract

We estimated age at attainment of sexual maturity and examined reproductive seasonality for male spotted dolphins, Stenella attenuata, from the eastern tropical Pacific Ocean. Maturity was determined by histological examination of testes. Average age at sexual maturation was 14.7 yr (the mean of two readers' age estimates). Testis and epididymis weight and seminiferous tubule diameters were reliable indicators of maturity, whereas age, length and color phase were less reliable. Seasonality was determined by changes in testis and epididymis weight, relative quantity of spermatids and spermatozoa, and lumen diameter, as well as an index of testis development (weight of the right testis and epididymis divided by length of the right testis). Testis and epididymis weights and index values peaked in July and August, midway between two predicted mating seasons for the northern offshore stock, but spermatozoa levels were elevated during the predicted breeding seasons.
AXIAL MUSCULATURE IN THE DOLPHIN (TURSIOPS TRUNCATUS): SOME ARCHITECTURAL AND HISTOCHEMICAL CHARACTERISTICS
Authors: Bello M. A. , Roy R. R. , Martin T. P. , Goforth H. W. , Edgerton V. R.
Published: August 2006

Abstract

In view of the supposition that a dolphin can swim faster than would be predicted based on its physical features and presumed muscle power potential, studies were initiated to reevaluate the assumptions made in reaching these conclusions. Several previous studies have shown that the architectural and histochemical properties of a skeletal muscle dictate its force, velocity and displacement properties. This study examined the muscle fiber lengths and tendon arrangements of the dorsal and ventral axial muscles in dolphins (Tursiops truncatus). Fiber type and fiber size distributions were determined to reflect the general biochemical characteristics of the musculature. The dorsal muscles had a higher mean fiber length (167 Vs. 90 mm) and the range within and across different dorsal muscles was less (141–199 vs. 37–185 mm) than in the ventral muscles. Both the dorsal and ventral muscles consisted of an overall mean of 50 percent slow twitch and 50 percent fast twitch fiber types. The fast twitch fibers were 67 percent larger (2,200 vs. 1,317 μm2) than the slow twitch fibers in the ventral and 38 percent larger (1,213 Vs. 879 μm2) in the dorsal muscles. In addition, the mean cross sectional area of the fibers in the ventral muscles was approximately 65 percent greater (1,750 vs. 1,072 μm2) than those in the dorsal muscles. The shorter, larger‐diameter fibers of the ventral musculature give it a greater potential for force production for a given amount of muscle mass. In contrast, the dorsal muscles appear to be designed to optimize velocity and displacement, (i.e., longer fibers). These findings contribute to the information necessary for the determination of the power potential of the musculature of the dolphin.
A MASS STRANDING OF SPERM WHALES IN OREGON: SEX AND AGE COMPOSITION OF THE SCHOOL
Authors: Rice Dale W. , Wolman Allen A. , Mate Bruce R. , Harvey James T.
Published: August 2006

Abstract

A school of 41 sperm whales, Physeter macrocephalus, that stranded near the mouth of the Siuslaw River, Oregon (43°59′N, 124°08′W), on 16 June 1979 consisted of 13 males and 28 females. Their ages were estimated by assuming that each postnatal dentin layer represents one year. The males were all sub‐adults, 9.3–11.5 m long and 14–21 yr old. The females were 9.3–11.4 m long, and 11 to about 58 yr old. Ten females were dissected; nine were sexually mature and three were carrying fetuses 2.64–4.62 m long. None of the 28 females was visibly lactating.
GROWTH IN YOUNG GRAY WHALES (ESCHRICHTIUS ROBUSTUS)
Authors: Sumich James L.
Published: August 2006

Abstract

Mean body lengths of gray whale calves were found to increase linearly from 4.6 m at birth to 7 m by weaning at six mo. After weaning, rates of length increase diminish, with calves reaching 8 m by one yr of age and 9 m by two yr. Evaluations of the weights of nine gray whales as functions of their measured lengths and girths reduce the emphasis placed on fast‐induced seasonal variations in girth by Rice and Wolman (1971). From birth weights of just under one metric ton, calves double their weights by three mo of age and double again by weaning at six mo.
GEOGRAPHIC PATTERNS OF VARIATION IN OFFSHORE SPOTTED DOLPHINS (STENELLA ATTENUATA) OF THE EASTERN TROPICAL PACIFIC OCEAN
Authors: Schnell Gary D. , Douglas Michael E. , Hough DanielJ.
Published: August 2006

Abstract

The spotted dolphin (Stenella attenuata), a species commonly associated with the tuna fishery, is widely distributed in the eastern tropical Pacific Ocean (ETP). Geographic patterns in morphological characteristics of this dolphin were evaluated for 36 skull measurements of 574 museum specimens allocated to 5° latitude‐longitude blocks. A strong subdivision between northern and southern offshore populations was demonstrated using principal components, canonical variates and cluster (UPGMA and function‐point) analyses of block means derived from standardized, sex‐adjusted measurements. Classification functions derived from a stepwise multiple discriminant analysis correctly identified more than 87 percent of the specimens as being from either a northern or southern locality. These results support recognition of southern spotted dolphins as a separate management stock. Dolphins from a sample representing a far‐western locality show similarities with those from the south. Patterns of geographic variation in morphology were evaluated using Mantel tests and matrix correlations; 17 of the 36 characters showed regional patterning and 18 exhibited local patterning. Morphological trends were also assessed with respect to 14 oceanographic measures that characterize environmental variability in the ETP. In general, clinal variation in morphology mirrors a north‐south trend found in several environmental variables. Overall, the most striking associations between morphological and environmental variables involved Solar Insolation (Jan.). Sea surface temperatures also exhibited a strong association with morphological variables; the highest correspondence was found between width of the temporal fossa and sea surface temperature in July. In addition, the thickness of the oxygen minimum layer exhibited a pattern of variation that was statistically associated with 58 percent of the skull characters. The geographic patterns found for cranial morphology and environmental measures are strongly clinal and in general congruent, suggesting that oceanographic conditions in part determine trends in morphological characteristics of spotted dolphins.
THE DISTRIBUTION OF BOWHEAD WHALES, BALAENA MYSTICETUS, IN THE CHUKCHI SEA
Authors: Miller R. V. , Rugh D. J. , Ohnson J. H.
Published: August 2006

Abstract

Under a U.S.‐U.S.S.R. cooperative Marine Mammal Project, shipboard cruises were made in 1979, 1980 and 1982, primarily to determine whether there is a substock of western Arctic bowhead whales (Balaena mysticetus) that summers in the western Chukchi Sea instead of migrating to the Beaufort Sea. More than 100 bowheads were sighted along the north Chukotka coast of Siberia in October 1979, and more than 200 bowheads were sighted there in September 1980. None were seen anywhere in the Chukchi Sea in late July and August 1982. We conclude that the September and October sightings were of animals returning early from the Beaufort Sea and that, other than occurrences peripheral to the main migration, there are no large concentrations in the Chukchi in the summer and there is apparently no western Chukchi substock.
THE EARLIEST SIRENIAN (MAMMALIA: DUGONGIDAE) FROM THE EASTERN PACIFIC OCEAN
Authors: Domning Daryl P. , Ray Clayton E.
Published: August 2006

Abstract

The partial skull and mandible of an unidentified halitheriine dugongid, collected from the Early Miocene Nye Mudstone in Lincoln County, Oregon, USA, is the earliest record of the Sirenia in the eastern Pacific Ocean. It is probably earlier than Early or Middle Miocene sirenians recently found in Peru, and is definitely earlier than any known from California or Baja California. However, it appears to be slightly younger than fossil sirenian remains recently reported from Late Oligocene rocks in Japan. The Oregon specimen is also the most northern record of the Sirenia on the west coast of North America prior to the Pleistocene although other sirenians did evidently reach and surpass such latitudes by the Late Miocene when a dispersal took place from America to the North Pacific coasts of the Old World. The Oregon specimen probably represents sirenians that spread to the North Pacific from the Caribbean, quite possibly prior to the Miocene. The Nye Mudstone was deposited during the warmest period of the Neogene on the coast of Oregon, and it does not seem necessary to postulate a greater degree of cold‐tolerance for the Oregon sirenian than is exhibited by living sea cows.
THE FOSSIL WHALE, BALAENOPTERA DAVIDSONII (COPE 1872), WITH A REVIEW OF OTHER NEOGENE SPECIES OF BALAENOPTERA (CETACEA: MYSTICETI)
Authors: Demeré Thomas A.
Published: August 2006

Abstract

The Pliocene fossil whale, Eschrichtius davidsonii Cope 1872, is actually a balaenopterid mysticete referable to the modern genus Balaenoptera Lacépède 1804. Redescription of the holotype of B. davidsonii (a partial left dentary), together with the discovery and description of a nearly complete right dentary referrable to this taxon, demonstrates the taxonomic and systematic affinities of Balaenoptera davidsonii.

Although originally thought to be Miocene in age, newspaper accounts of 1872 indicate that the holotype of B. davidsonii was actually collected from fossiliferous sandstones here referred to the San Diego Formation of Late Pliocene age (equivalent to the Blancan North American Land Mammal Age).

Comparisons between the dentary of B. davidsonii and dentaries of other extant and fossil balaenopterids allow recognition of several taxonomically useful mandibular characters (i.e., degree of longitudinal curvature of horizontal ramus and form of transverse cross‐sectional outlines). A taxonomic review of other nominal Neogene species of Balaenoptera from Europe and eastern North America is an initial attempt at stabilizing the confusing nomenclatural history and taxonomy of this group. In this regard, the genus Burtinopsis Van Beneden 1872 is placed in synonymy with Balaenoptera.

Generic reassignment of the fossil rorqual Balaenoptera davidsonii (Cope 1872) creates a nomenclatural problem of homonymy with the extant minke whale Balaenoptera davidsoni Scammon 1872. As Cope's species is a senior homonym of Scammon's, suppression of Scammon's name is recommended. The new trinomen Balaenoptera acutorostrata scammoni n. ssp. is here proposed for the North Pacific minke whale.
SIZE‐CLASS SEGREGATION OF BOWHEAD WHALES DISCERNED THROUGH AERIAL STEREOPHOTOGRAMMETRY
Authors: Cubbage James C. , Calambokidis John
Published: August 2006

Abstract

Bowhead whales (Balaena mysticetus) summering in the eastern Beaufort Sea in 1983 were measured through aerial stereophotogrammetry. Photos were taken from a turbine Aerocommander 690 with wingtip‐mounted, calibrated 35‐mm cameras. Photos were measured on an analytical plotter with scale data provided by radar altimeter and focal length of the lenses. Coefficient of variation of known‐sized targets 12 m long was 1.7 percent (n= 25). Potential duplicate photographs of whales were removed from consideration through an algorithm based on whale swim speed and elapsed time between sightings. Significant segregation by bowhead whale length was found between four broad regions (P < 0.001, ANOVA, Chi square). Also an inverse correlation appeared between longitude and size of animals (P < 0.001), with the larger animals occurring farther east. This unequivocal size‐class segregation confounds an accurate assessment of overall size‐class composition of the population as well as recent attempts to determine calving rate from aerial survey data.
DIEL HAUL‐OUT PATTERNS AND SITE FIDELITY OF HARBOR SEALS (PHOCA VITULINA RICHARDSI) ON SAN MIGUEL ISLAND, CALIFORNIA, IN AUTUMN
Authors: Yochem Pamela K. , Stewart Brent S. , DeLong Robert L. , DeMaster Douglas P.
Published: August 2006

Abstract

We studied the haul‐out patterns and movements of harbor seals (Phoca vitulina richardsi) on San Miguel Island, California, from 23 October through 6 December 1982 by attaching a radio transmitter to each of 18 seals and monitoring their presence ashore with continuously scanning receivers. Seals hauled out at all hours although, on average, the largest proportion of tagged seals was ashore between 1300 and 1500 h. Median durations of haul‐out bouts of individual seals ranged from 4.7 to 21.8 h; 81% of all haul‐out bouts were less than 12 h and 3% were longer than 24 h. Eighty‐one percent of the seals that were resighted at least twice used only the sites where they were tagged; two seals used two sites and one seal used three. Most seals were hauled out on fewer than 51% of the days sampled. On average, about 41% of tagged seals hauled out each day whereas an average of about 19% was hauled out during peak afternoon hours. Using telemetry data to correct a count of 412 seals made during an aerial survey, we estimated absolute abundance at about 2,168 seals; a modified Peterson mark‐recapture model produced an estimate of about 1,445 seals.
IMPLICATIONS FROM PHYSIOLOGICAL STUDIES OF MARINE MAMMALS1
Authors: Elsner Robert , Wickham Lori L.
Published: August 2006

Some aspects of captive marine mammal research have become matters of controversy, largely due to a misunderstanding of the value of such studies and of their importance to effective management and conservation of these species. Understanding of the physiological mechanisms underlying the special adaptations for aquatic life that marine mammals demonstrate provides essential information relating to their health and survival. The need for such information is increasing as disturbance of the world's marine environments steadily escalates. While studies of these animals in their natural habitats contribute much to our comprehension of their biology, a more complete understanding of the physiological basis of their behavior depends upon experimental laboratory investigations. Some of the new knowledge thus gained has potentially important implications for human medicine.
BEHAVIORAL AND PHYSIOLOGICAL MEASUREMENTS OF MATERNAL INVESTMENT IN THE STELLER SEA LION, EUMETOPIAS JUBATUS
Authors: Higgins Lesley V. , Costa Daniel P. , Huntley Anthony C. , Le Boeuf Burney J.
Published: August 2006

The onshore and at‐sea cycles of females, suckling behavior of pups and their milk intake were studied in Steller sea lions (Eumetopias jubatus) during 1983 at Año Nuevo Island, California. Females averaged approximately 21 h ashore and 36 h at sea. The trips to sea lengthened as pups aged, resulting in an overall decline in female time ashore to 30% by the sixth week following parturition. Activity budgets of pups showed no significant differences among suckling time, age and sex. Milk intake, estimated using labeled water studies, revealed that heavier pups consumed more milk than lighter ones (milk ingestion in ml/d = 4.26 + 0.0687 [Pup Mass in kg]). Mean milk intake was 1.78 ± 0.33 liters/d. Mean pup growth rate was 0.38 ± 0.1 kg/d. The results suggest that female attendance patterns are shaped by the increasing nutritional demands of growing pups and their increasing efficiency at suckling.
A COPROLOGICAL SURVEY OF HELMINTH PARASITES OF THE HAWAIIAN MONK SEAL FROM THE NORTHWESTERN HAWAIIAN ISLANDS
Authors: Dailey Murray D. , Santangelo Richard V. , Gilmartin William G.
Published: August 2006

In conjunction with an Hawaiian monk seal, Monachus schauinslandi, breeding enhancement program, fecal samples were examined for the presence of helminth parasite products (eggs, larvae, and proglottids). Eighty‐two samples were examined from four island groups in the northwestern Hawaiian Islands: 38 from Kure Atoll, 32 from French Frigate Shoals, 11 from Laysan Island, and one from Lisianski Island. Identified helminth products include those of Diphyllobothrium sp., D. cameroni, Contracaecum turgidum, Anisakis sp., Corynosoma rauschi, and Trematoda. In addition, eggs from Halarachne laysanae (Atari) were found in 3 samples. Eggs of C. turgidum were present in the highest percentage (>64%) of samples from all locations. Eggs of Anisakis sp. and Trematoda are reported from this host for the first time.
GEOGRAPHIC VARIATION IN TOOTH MORPHOLOGY AND DENTINAL PATTERNS IN THE SPINNER DOLPHIN, STENELLA LONGIROSTRIS
Authors: Akin Priscilla A.
Published: August 2006

Sixteen tooth characters were analyzed in 277 specimens of spinner dolphins (Stenella longirostris) from the eastern tropical Pacific to determine whether the characters were associated with size of the animal, species‐stock membership or geographic location. The tooth characters included 5 continuous measurements and 11 qualitative variables. Statistical analyses of the characters included two‐way ANOVA tests which assessed continuous measurement variables for differences based on stock membership, latitude and longitude of collection or whether the animal was collected north or south of the equator. Principal component analyses combined factors of continuous variables with those of qualitative variables into components which were used as variables in further analyses. Discriminant analyses were performed using continuous variables alone and using principal components as potentially discriminating variables. Results showed that tooth differences were not associated with size but significant differences were found in some tooth variables with stock membership, incremental changes in latitude and whether the animal was collected north or south of the equator. A discriminant function, containing only tooth length, correctly classified 67% of northern and 78% of southern animals according to location of collection north or south of the equator.
THE DISTRIBUTION OF WHITE‐SIDED (LAGENORHYNCHUS ACUTUS) AND COMMON DOLPHINS (DELPHINUS DELPHIS) VS. ENVIRONMENTAL FEATURES OF THE CONTINENTAL SHELF OF THE NORTHEASTERN UNITED STATES
Authors: Selzer Lawrence A. , Payne P. Michael
Published: August 2006

Sightings of white‐sided (Lagenorhynchus acutus) and common dolphins (Delphinus delphis) from survey vessels operating on the continental shelf of the northeastern United States were recorded during spring and fall of six years. Distributions of these sightings were compared with sea surface temperature and salinity, and bottom topography. The apparent geographic distributions of the two species are complementary, although there is a broad overlap. White‐sided dolphins occurred primarily within the Gulf of Maine, but also on Georges Bank and in the mid‐Atlantic region. Common dolphins were abundant within a broad band paralleling the continental slope (100–200 m depth contour) from latitude 35°N to the northeast peak of Georges Bank. Sightings of this species were distributed primarily along the edge of the continental shelf south of 40°N in spring and north of this latitude in fall. Few sightings of common dolphins occurred in the Gulf of Maine.

Although both species of dolphins were sighted more frequently in areas of high sea floor relief, white‐sided dolphins occurred in areas where sea surface temperatures and salinities are low while common dolphins were sighted in warmer, more saline waters. However, these environmental conditions may be only secondarily influencing dolphin distribution. Seasonal variation in sea surface temperature and salinity, and local nutrient upwelling in areas of high sea floor relief may affect preferred prey abundances, which in turn may affect dolphin distribution.
DYNAMIC RESPONSE ANALYSIS. III. A CONSISTENCY FILTER AND APPLICATION TO FOUR NORTHERN ELEPHANT SEAL COLONIES
Authors: Boveng Peter , DeMaster Douglas P. , Stewart Brent S.
Published: August 2006

Dynamic response analysis, a technique for determining stock size relative to the maximum net productivity level (MNPL), was applied to northern elephant seal populations from the South Farallon Islands, Año Nuevo Island, San Nicolas Island and San Miguel Island. Pup counts were used as indices of population size. The application of dynamic response analysis presented here involved some methodological innovations. We present a moving interval method which involves calculating separate dynamic response analyses for intervals of various lengths ranging from four counts to the total number available for the colony. The sign of the second order polynomial regression coefficient computed from a particular interval was used to indicate the colony's apparent status (relative to its MNPL, += above MNPL, ‐ = below MNPL) on that interval. Consistency in the sign of the second order coefficient, as the interval was moved along the trajectory, was used to determine the minimum reliable interval size. Each colony exhibited growth similar to that of a population below its MNPL. These results are consistent with recent natural history observations at San Nicolas, San Miguel and the South Farallon islands. Natural history observations at Año Nuevo Island suggest that the colony there is now at equilibrium. Thus, if our results from dynamic response analysis of the Ano Nuevo colony are correct, it appears that the MNPL may be close to the carrying capacity for these animals.
LONG‐TERM TRENDS IN ABUNDANCE AND DISTRIBUTION OF MANATEES (TRICHECHUS MANATUS) IN THE NORTHERN BANANA RIVER, BREVARD COUNTY, FLORIDA
Authors: Provancha J. A. , Provancha M. J.
Published: August 2006

Abstract

Four aerial survey projects were conducted between 1977 and 1986 to determine the abundance, density and distribution of West Indian manatees (Trichechus manatus), in the northern Banana River, Kennedy Space Center, Florida. Manatee density and distribution within selected portions of the 78.5 km2 study area were determined. Peak numbers of manatees occurred in spring of each year. The maximum counts increased from 56 in 1978 to 297 in 1986. Manatee abundance was lowest in the winter of each year. Mean density per flight increased from 0.52 manatees/km2 in 1977–78 to 2.73/km2 in 1984–86. This increase may reflect increases in the east coast population or shifts in the population distribution. Distributional changes were observed in the study area through time, with a lower percentage of manatees occurring in industrial areas and a correspondingly higher percentage of manatees in nonindustrial areas by 1985.
GENETIC RELATEDNESS OF TWO POPULATIONS OF THE SOUTHERN ELEPHANT SEAL, MIROUNGA LEONINA
Authors: Gales Nicholas J. , Adams Mark , Burton Harry R.
Published: August 2006

Blood samples from southern elephant seals (Mirounga leonina) from Heard and Macquarie Islands were surveyed electrophoretically for protein variation. Thirty proteins encoded by a minimum of 35 loci were screened, four of which were found to be polymorphic. Statistically significant differences in allele frequencies were found between the two populations at three loci. Heterozygosity estimates for the Heard and Macquarie island populations were 0.034 ± 0.020 (mean ± standard error) and O.029 ± 0.017 respectively, with a Nei distance of 0.007. The findings suggest that the two populations may have diverged genetically and very limited gene flow exists between the islands, a finding consistent with limited information from mark‐recapture studies.
MOVEMENTS, HOME RANGE, AND TERRITORIES OF MALE SEA OTTERS OFF CENTRAL CALIFORNIA
Authors: Jameson Ronald J.
Published: August 2006

Abstract

Sixty male sea otters (Enhydra lutris) were tagged on the rear flippers with colored tags. Of these, 46 (77%) were resighted. Movements of 127 km were documented for adults and 187 km for subadults. Adults maintained breeding territories that averaged 40.3 ha (n= 10, SE = 4.0). They returned to the same territory seasonally for up to seven consecutive years. Territorial males moved from areas of high male abundance to areas of high female abundance on a seasonal basis. During the winter, 74% of adult males left breeding areas and joined concentrations of males located near the ends of the range. Thirty percent of the subadult males were observed in male groups near the extremities of the range. During the summer and fall, the density of adult males (15/1,000 ha) and adult male to independent otter (non‐pup) ratio (1:5) in female areas was highest. The number of adult males in areas of female abundance was inversely related to the number of dependent pups, perhaps because when pup numbers are low (late summer and fall) the number of estrous females is high. Subadult males may remain in female areas on a year round basis until their second or third year. However, they were not generally associated with adult females.
CHEMICAL RESTRAINT AND ANESTHESIA OF PINNIPEDS: A REVIEW
Authors: Gales Nicholas J.
Published: August 2006

Abstract

Drugs used to restrain and anesthetize pinnipeds have included neuromuscular blocking agents, narcotic analgesics, barbiturates, cyclohexamines, ataractics and inhalational agents. Problems associated with narrow margins of safety, thermoregulatory disturbances, cardiovascular changes and fatalities have excluded all but the cyclohexamines, ataractics and inhalational agents from presently accepted drugs for chemical restraint and anesthesia of pinnipeds. Combinations of tiletamine hydrochloride and zolazepam hydrochloride show great promise for immobilizing some species of pinnipeds in the field and inhalational agents are recommended for surgical anesthesia.
HAUL‐OUT PATTERNS, SITE FIDELITY AND ACTIVITY BUDGETS OF MALE HOOKER'S SEA LIONS (PHOCARCTOS HOOKERI) ON THE NEW ZEALAND MAINLAND
Authors: BEENTJES MICHAEL P.
Published: August 2006

Abstract

Diurnal and seasonal haul‐out patterns, site fidelity and activity budgets of individually identified Hooker's sea lions were studied for two years at Papanui Beach, Otago Peninsula, New Zealand.

Fourteen male sea lions were identified. Lengths ranged from 1.65 m–2.28 m and estimated ages from 2‐11 yr. The population consisted of four sexually and socially mature (potentially breeding), eight sexually mature but socially immature and two immature males. Most haul‐outs (95.6%) were by nine identifiable individuals (Residents) returning on a regular basis, suggesting a high degree of site specificity. Emigration and recruitment were low in relation to the length of the study. Daily arrivals (mean = 0844 h, SD = 1.49) and departures (mean = 1802 h, SD = 1.18) indicate nocturnal feeding. During March 1986 sea lions spent 43.8% of each day ashore (= 78% of daylight hours). Numbers of sea lions hauled out declined in both breeding seasons; in 1986/87 this was due to a decrease in haul‐out frequency of resident animals. All but one of these sea lions returned after the breeding season.

Sea lions preferentially selected the middle and the extreme ends of the beach as haul‐out sites. During winter use was made of the grass dunes as haul‐out areas.

There were significant differences in the frequencies of behavioral activities between summer and winter; more time was allocated to resting in summer.
HARBOR SEAL TRACKING AND TELEMETRY BY SATELLITE
Authors: Stewart Brent S. , Leatherwood Stephen , Yochem Pamela K. , Heide‐Jørgensen Mads‐Peter
Published: August 2006

Abstract

We tested a satellite Platform Transmitter Terminal (PTT) in the laboratory (on a float and on captive seals) and on a free‐ranging harbor seal in the Southern California Bight to investigate the utility of satellite telemetry in documenting seals’at‐sea behavior and movements. We used records from a microprocessor‐based time‐depth recorder (TDR) to interpret location and diving records from the PTT. For the free‐ranging harbor seal, we obtained at least one uplink during 70% (while the seal was at sea) to 82% (while she was ashore) of satellite passes and at least one location each day. Of 62 locations determined by Service Argos for the free‐ranging seal, 20 were verified from TDR records to have been at sea; these indicated that the seal may have ranged up to 48 km from the haul‐out site, although most locations were within 5 km. The accuracies of locations calculated when the seal was at sea (±15 km) were substantially less than when it was ashore (±1.5 km), thus limiting at‐sea tracking of seals by satellite to rather gross movements. Fewer transmissions were detected and locations calculated when the seal was actively diving than when it was swimming near the surface as it departed from or returned to the haul‐out site. Consequently, average dive durations indicated by the PTT were substantially shorter than those calculated from TDR records. Documentation of foraging areas and detailed at‐sea movements using satellite technology may not be possible for pinnipeds unless PTT‐transmission rates are increased substantially from the 1 per 45 set maximum rate now permitted by Service Argos.
QUANTITATIVE DETERMINATION OF OPTIMUM SUSTAINABLE POPULATION LEVEL
Authors: Gerrodette Tim , DeMaster Douglas P.
Published: August 2006

Abstract

Quantitative methods are reviewed and compared for determining whether a marine mammal population is at an optimum sustainable population (OSP) level, a management goal specified by the U.S. Marine Mammal Protection Act. Methods of OSP determination fall into two general types: those that require an estimate of a population's maximum net productivity level (e.g., the back‐calculation method) and those that do not (e.g., dynamic response analysis). The two types differ in the data they require and in whether they determine OSP with respect to present or historical carrying capacity. Back‐calculation and dynamic response analyses are compared using data on the California gray whale (Eschrichtius robustus.) Marine mammal monitoring programs should be designed to detect trends in both the abundance of a population and its condition relative to carrying capacity, because both quantities are involved in the definition of OSP. The value of using both abundance and condition indices in an assessment is illustrated with data on the northern fur seal (Callorhinus ursinus.)
DENSITY DEPENDENCE IN NORTHERN FUR SEALS (CALLORHINUS URSINUS)
Authors: Fowler Charles W.
Published: August 2006

Abstract

This paper summarizes, updates, and interprets information on density‐dependent dynamics of populations of the northern fur seal (Callorhinus ursinus). Density‐dependent changes observed in these populations have involved various aspects of growth (body length, body weight, tooth weight, and size of other skeletal parts, especially the skull), survival, age at maturation, incidence of disease, and time spent foraging. For the population of northern fur seals on St. Paul Island of the Pribilof Islands, which was observed during a major increase and during two significant declines, density‐dependent changes that occurred during the growth of the population were reversed during the declines. The Robben Island population in the western Pacific declined after 1965, and the decline was accompanied by changes similar to those observed during the declines on the Pribilof Islands. Although data are not available for all age and sex classes, it appears that most or all components of the populations exhibit similar changes. The overall implication of these changes is that current populations on Robben Island and the Pribilof Islands are reduced to levels below what could be supported by the resources available in their environments. Density dependence for this species is consistent with that of other large mammals, specifically in that vital rates for fur seals ate related to density in a nonlinear fashion.
THE MOST NORTHERLY HARBOR SEAL,PHOCA VITULINA, AT PRINS KARLS FORLAND, SVALBARD
Authors: Prestrud Pål , Gjertz Ian
Published: August 2006

Abstract

The harbor seal (Phoca vitulina) has its northernmost distribution at the Norwegian arctic archipelago of Svalbard. Little information exists on this particular harbor seal population. The present paper summarizes this information, and gives the result of surveys of harbor seals conducted in Svalbard in 1984, 1985 and 1987. These surveys show that harbor seals in Svalbard are limited to the area around Prins Karls Forland, the westernmost island in the archipelago. The harbor seal population at Prins Karls Forland numbers at least five to six hundred animals.
ENTANGLEMENT IN MAN‐MADE DEBRIS OF ANTARCTIC FUR SEALS AT BIRD ISLAND, SOUTH GEORGIA
Authors: Croxall J. P. , Rodwell S. , Boyd I. L.
Published: August 2006

Abstract

Neck collars of man‐made marine debris were seen on 208 Antarctic fur seals (and removed from 170) during the 142 days of the 1988–1989 pup‐rearing season at Bird Island, South Georgia. This represents at least 0.1% of the total Bird Island population and a minimum of 0.4% of animals in the best covered areas; a maximum value might approach 1%. Polypropylene straps (packaging bands) formed 59% of collars, nylon string (16%), fishing net (13%) and six other materials comprised the rest. Males accounted for 71% of entanglements, 88% of which were of young (1–4 yr old) animals; females accounted for 64% of animals older than this. Obvious physical injury was being caused to 30% of animals and only on 19% of animals was the collar loose enough potentially to come off. The magnitude of the problem at South Georgia is similar to that with northern fur seals at the Pribilof Islands, where a significant population decline has occurred concurrently. Antarctic fur seals are still increasing in numbers but stricter controls on the jettisoning of debris into the Southern Ocean ate needed if the entanglement problem is not to increase beyond the level of a potential threat.
Books
Authors: Shaughnessy Peter
Published: August 2006

Book review in this Article

THE PINNIPEDS: SEALS, SEA LIONS, AND WALRUSES. M. Riedman. University of California Press, Berkeley. ISBN O‐520‐06497‐6. 439 pp. 1990. Price $29.95 (U.S.) (hard‐bound).
DIVING PATTERNS OF NORTHERN ELEPHANT SEAL BULLS
Authors: DeLong Robert L. , Stewart Brent S.
Published: August 2006

Abstract

We used small microprocessor‐based, time‐depth recorders to document the diving patterns of six adult male northern elephant seals (Mirounga angustirostris) from San Miguel Island, California. The recorders stored measurements of hydrostatic pressure every 30 or 60 set while the seals were at sea for 107 to 145 d in spring and early summer; collectively, over 36,000 dives were recorded. Seals dove continually while at sea, most often to depths of 350–450 m although two seals had secondary modes at about 700–800 m; maximum depths for two seals of 1,333 m and 1,529 m are the deepest yet measured for air‐breathing vertebrates. Seals were submerged about 86% of the time they were at sea, rarely spending more than 5 min at the surface between dives; 99% of all post‐dive surface intervals were shorter than 10 min. Dives averaged 21–24 min, the longest was 77 min. The uninterrupted patterns of long dives punctuated by brief surface periods suggest that most if not all dives were well within these seals’aerobic limits. Dives of bulls were, on average, about 18% longer than those published earlier for cows, evidently because of the substantially greater body mass of bulls and allometric scaling of dive endurance. Dive depths and dive durations varied seasonally; depths were greatest in spring, durations greatest in early summer. During each season dives were deepest during the day and shallowest at night except for the sixth seal whose consistently shallow dives (50–150 m) in spring were independent of time of day. Prey remains recovered by lavage from seals’stomachs were primarily of vertically migrating, epi‐ and meso‐pelagic squid. The die1 patterns in dive depths suggest that five seals dove to and foraged in the offshore mesopelagic zone, pursuing those vertically migrating prey. The sixth seal behaved similarly in early spring and early summer but may have foraged in nearshore epibenthic habitats in spring.
SEA OTTER DIETS IN A DECLINING POPULATION IN ALASKA
Authors: Green Gregory A. , Brueggeman John J.
Published: August 2006

Abstract

Diet of sea otters (Enhydra lutris) using a haulout site on the north side of the Alaska Peninsula was determined from 50 scats. Dominant prey species were mussels (Mytilus edulis), followed by three species of clams (Siliqua spp., Spisula polynyma, and Tellina lutea), sand dollars (Echinarachnius parma), and helmet crabs (Telmessus cheiragonus). Our results support preliminary findings by Cim‐berg et al. (1984) that this sea otter population preys heavily on mussels and that the presence of low caloric value sand dollars in their diet is significant. Coupled with population estimates, our results also provide evidence that this population of sea otters may be declining due, in part, to overdepletion of food resources.
THE NARWHAL, MONODON MONOCEROS, IN THE NORWEGIAN HIGH ARCTIC
Authors: Gjertz Ian
Published: August 2006

Abstract

Narwhals (Monodon monoceros) are known to frequent the waters of the Norwegian arctic archipelago of Svalbard. An attempt is made to summarize narwhal observations from the Svalbard area, and from this to deduce their distribution. Observations have been gathered from the literature, sealing vessel log books and official statistics. Interviews have also been conducted with residents of Svalbard. I con&de that narwhals are most frequently observed in the area off the north‐west corner of Spitsbergen.
OCCURRENCE AND BEHAVIOR OF THE SOUTHERN RIGHT WHALE DOLPHIN LISSODELPHIS PERONII OFF NAMIBIA
Authors: Rose Barrie , Payne Andrew I. L.
Published: August 2006

Abstract

The southern right whale dolphin Lissodelphis peronii is a seldom seen cetacean of southern latitudes. Off southern Africa, observations have been made predominantly in the major upwelling area off Lüderitz, Namibia, but the species has now also been seen south of the Orange River in South African waters. Sightings for the years 1980–1990 are documented and they reveal that L. peronii occurs off southern Africa both inshore and offshore and throughout the year. An opportunity for extended observation in January 1989 afforded the opportunity to record some interesting behavior patterns.
A PATERNITY TEST CASE FOR THE KILLER WHALE (ORCINUS ORCA) BY DNA FINGERPRINTING
Authors: Hoelzel A. Rus , Ford John K. B. , Dover Gabriel A.
Published: August 2006

Abstract

The minisatellite DNA profiles from four captive killer whales (two adult males, a female and her calf) were compared to determine paternity between two potential fathers. One of the males was clearly excluded, while the other shared all paternal bands with the calf. The background of this technique, and its potential applications in captive breeding programs and field studies are discussed.
RATE OF INCREASE, 1978–1988, OF BOWHEAD WHALES, BALAENA MYSTICETUS, ESTIMATED FROM ICE‐BASED CENSUS DATA
Authors: Zeh Judith E. , George John C. , Raftery Adrian E. , Carroll Geoffry M.
Published: August 2006

Abstract

The number of bowhead whales, Balaena mysticetus, passing within viewing range of the ice‐based census at Point Barrow, Alaska, during spring migrations from 1978 to 1988 is estimated from the visual census data. The trend in the annual numbers yields an estimated rate of increase of 3.1% per year with a 95% confidence interval ranging from 0.1% to 6.2% for the Bering‐Chukchi‐Beaufort Seas bowhead stock during this period. Alternative treatments of the data suggest less precise or somewhat lower estimates, but all results indicate that the stock was increasing.
THE ROLE OF PREDATION IN THE ECOLOGY OF THE RINGED SEAL IN BARROW STRAIT, NORTHWEST TERRITORIES, CANADA
Authors: Hammill M. O. , Smith T. G.
Published: August 2006

Abstract

Predation on ringed seals (Phoca hispida) was examined in Barrow Strait between March and May 1984 to 1986. Polar bears were the most important predator. Evidence of bear predation was observed at 18–30% of the ringed seal subnivean structures we located. Ten to 24% of predation attempts were successful, with pups making up 75% to 100% of the seals killed. Bears killed an average of 0.08 to 0.51 seals/km2, which comprised 8 to 44% of the estimated annual pup production. Bears were successful on average in 11.3% of their attempts to kill pups hidden inside birth lairs. On southeast Baffin Island where snow was soft and pups were exposed, bears were successful in 33.5% of their attempts to kill a seal. Negative correlations were found between mean snow depth and predation by polar bears (r= ‐0.896, P= 0.04, n= 5) in 1985, and between snow depth and the number of predation attempts (r= ‐0.613, P= 0.02, n= 14) in 1986.