摘要:

AbstractResearch 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

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1985.tb00008.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractControversy 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 equa

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1985.tb00009.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractDaily counts of Southern sea lions (Otaria byronia) made at Punta Norte, Argentina, during four consecutive breeding seasons (1980–1984) yielded similar results in the time of the reproductive events. Males and females began to arrive during the second week of December. Males reached peak numbers (100–110) between 15 and 21 January. Females reached maximum numbers (300–350) at the end of January. About 380–430 pups were born between December 20 and February 2, and 70–80 percent of births occurred between 10 and 25 January. Copulations peaked during the third week of January. The sex ratio of adult males to adult females at peak season fluctuated from 1:3.7 to 1:4.2. By the first week of February, coinciding with the maximum number of young males (25–50), 90 percent of the adult males had abandoned the area and the number of females fluctuated greatly. Since 1980 the number of females and pups has shown a slight increase, particularly during the 1983–1984 br

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1985.tb00010.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

AbstractThe underwater existence of marine mammals has encouraged a variety of special biophysical adaptations to their environment. Their sensory and communication systems reflect the transmission properties of sea water. For example, vision is keen in spectra that penetrate water best, vocalization is broadband and used at the frequencies that appear to fit their activities best—the differences in sensory use match the intriguing variety of behavior observed for each species. To date most of the observations of animal interactions with their marine environment have dealt with sound. There has been some work on vision and studies are underway to determine animal sensitivities to hydrodynamic pressure, chemical traces and magnetic fields. The species that have been recorded to date are listed and vocalizations are generally compared. Methods for observation of sensory mechanisms are noted along with a discussion of other aspects of marine mammal biophysics including vibrissal sensation and the biophysics of movement in a fluid environmen

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1985.tb00011.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1985.tb00012.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1985.tb00013.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Book reviews in this article:EcholocationInWhalesAndDolphins. P. E. Purves and G. E. Pilleri.Pathobiology ofMarineMammalDiseases. E. B. Howard (ed.).

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1985.tb00014.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0824-0469    

DOI:10.1111/j.1748-7692.1985.tb00015.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY