摘要:

AbstractQuantitative 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 ursin

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1990.tb00221.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractGroups ofEubalaena australisin the Gulf of San Jose, Argentina were characterized and classified. A one‐zero sampling method was used for collecting data. A distance matrix was calculated with the 124 groups recorded and 10 characters including composition, size, activities, belly‐up and tail‐up positions, flipper and tail slaps, and breaching. Cluster analysis separated groups into 12 types. Six low‐interaction group types were differentiated primarily by their composition, and extent of swimming and resting behaviors. Six interaction group types were characterized by the presence of whales in the belly‐up position, by group size, by the absence of females with calves, and by sexual activity. Some interpretations of the possible functional meaning of the observed group types are

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1990.tb00222.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractSize of canine teeth from California sea lion (Zalophus californianus californianus) carcasses is shown to be useful in determining the sex of animals which have missing genitalia or which are otherwise of unknown sex. A total of 267 canine teeth from carcasses of 68 males and 43 females were measured along five axes. Of root and crown measurements of upper and lower canines, males and females overlapped only in root thickness of upper canines. A multivariate ANOVA showed a significant difference in the size of canines between upper and lower canines, and between males and females. Stepwise discriminant analysis produced discriminant functions for upper and lower canines for determining sex of unknown‐sexed California sea lions. A separate set of canine teeth from 39 male and 49 female California sea lions was correctly classified without prior knowledge of sex by visual inspection and by the two discriminant function

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1990.tb00223.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractTooth weight and body length of juvenile male northern fur seals,Callorhinus ursinus, collected on St. Paul Island, Alaska, from 1948 to 1984 were compared. The relationship between these variables was investigated for individual and combined age classes. A density‐dependent increase in mean tooth weight occurred during a decline in fur seal abundance. Consistent, though poorly understood, differences in tooth weight were found among males associated with different rookeries (breeding grounds). Storing the teeth for long periods may affect the weights, but such effects, if any, are too small to account for the changes observe

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1990.tb00224.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe composition and properties of commercial oil collected from Uruguayan fur seals (Arctocephalus australisZimmermann) during 1985, 1986 and 1987 are reported. Oil recovered from some organs (kidney, heart, liver) and blubber were also analyzed. All have compositions similar to oils from other marine animals in commercial use, containing high percentages of long chain and polyunsaturated fatty acids.

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1990.tb00225.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

abstractThe close relationships of pinnipeds to other carnivorans were studied based on morphological characteristics of the bony tentorium (BT) and bony falx (BF) of carnivorans. It appears to be an important characteristic of the Carnivora that the clear BT is present in almost all species including pinnipeds. The BF is present in all species of pinnipeds, and only in the genusUrsusamong fissipeds observed.The parietal bone of all otariids and odobenids observed shows an extremely characteristic form as compared with other carnivorans. The sagittal and squa‐mous borders of the parietal bone of these groups are bridged by a thin bony plate which forms large portions of the BT and BF. In phocids, the aspects of the BT and BF vary among species, but are apparently distinct from those of otariids and odobenids.The BT of carnivorans can be divided into four types which appear to be useful for classification of the Carnivora. On the basis of the BT and BF form, the Otariidae and Odobenidae appear to have a specific sister relationship to the Ursidae, while the Phocidae appears to have dose affinities to the Mustelidae. Morphological differences of the BT and BF among pinnipeds strongly support the diphyletic origin of pinniped

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1990.tb00226.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1990.tb00227.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1990.tb00228.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1990.tb00229.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1990.tb00230.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY