Auditory sensitivity of northern fur seals (Callorhinus ursinus) and a California sea lion (Zalophus californianus) to airborne sound

1980 ◽  
Vol 68 (S1) ◽  
pp. S6-S6 ◽  
Author(s):  
R. J. Schusterman ◽  
P. W. B. Moore
Keyword(s):  
Auditory Sensitivity ◽  
Zalophus Californianus ◽  
Callorhinus Ursinus ◽  
Sea Lion ◽  
California Sea Lion ◽  
Airborne Sound ◽  
Fur Seals ◽  
Northern Fur Seals

Foraging characteristics of female northern fur seals (Callorhinus ursinus) and California sea lions (Zalophus californianus)

1990 ◽  
Vol 68 (1) ◽  
pp. 150-158 ◽  
Author(s):  
George A. Antonelis ◽  
Brent S. Stewart ◽  
Wayne F. Perryman
Keyword(s):  
Water Depth ◽  
Zalophus Californianus ◽  
Callorhinus Ursinus ◽  
California Sea Lions ◽  
Merluccius Productus ◽  
Sea Lions ◽  
Fur Seals ◽  
Northern Fur Seals ◽  
San Miguel Island ◽  
Northern Anchovy

The foraging characteristics of northern fur seals (Callorhinus ursinus) and California sea lions (Zalophus californianus) from San Miguel Island, California, were studied during the 1985 summer breeding season. A radio transmitter was attached to 25 postpartum females of each species and used to determine their locations at sea and the frequency and duration of their feeding trips. Northern fur seals usually foraged in the oceanic zone where the mean water depth was 933 m (n = 12). California sea lions principally were found in the neritic zone, where water depth averaged 323 m (n = 9). Most fur seals (92%) were found northwest of San Miguel Island, whereas the sea lions were commonly found to the northwest (55%) or in areas south (22%) of the island. Although both species evidently foraged at similar distances from the island, foraging trips of fur seals [Formula: see text] were over twice as long as those of sea lions [Formula: see text]. Fur seals were ashore less time [Formula: see text] than were sea lions [Formula: see text] between foraging trips. Analysis of scats revealed that fur seals and sea lions ate similar prey (northern anchovy, Engraulis mordax; Pacific whiting, Merluccius productus; juvenile rockfish, Sebastes spp.; market squid, Loligo opalescens; and nail squid, Onychoteuthis borealijaponicas), although the relative proportions of these prey differed. Factors influencing the observed foraging characteristics probably were availability of prey and phylogenetic constraints associated with life-history traits of northern fur seals and California sea lions.

Estimation of Sexual Maturity Based on Morphometrics of Genital Organs in Male Northern Fur Seals, Callorhinus ursinus

Mammal Study ◽  
2020 ◽  
Vol 46 (1) ◽  
Author(s):  
Yukino Hirakawa ◽  
Takanori Horimoto ◽  
Ippei Suzuki ◽  
Yoko Mitani
Keyword(s):  
Sexual Maturity ◽  
Callorhinus Ursinus ◽  
Fur Seals ◽  
Northern Fur Seals
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