Most analyses of the relationship between group size and food intake of social carnivores have shown a discrepancy between the group size that maximizes energy intake and that which is most frequently observed. Around southern Vancouver Island, British Columbia, killer whales of the so-called transient form forage in small groups, and appear to prey exclusively on marine mammals. Between 1986 a...

The Pinnipedia includes marine carnivores that share a single common evolutionary origin within arctoid carnivores 25–27 Ma in the North Pacific (Berta & Adam, 2001). Three major groups of pinnipeds are recognized: the Phocidae (true seals), the Otariidae (fur seals and sea lions) and the Odobenidae (walruses). Phocid seals, the focus of this study, are typically divided into two subfamilies th...

KOOYMAN, G. L., J. P. SCHROEDER, D. M. DENISON, D. D. HAMMOND, J. J. WRIGHT, and W. P. BERGMAN. Blood nitrogen tensions of seals during simulated deep dives. Am. J. Physiol. 223(5) : 1016-1020. 1972.-Three species of seal were subjected to a total of 65 simulated deep dives equivalent to depths ranging from 30 to 272 m (4-28.2 atm absolute (ATA)) in a hydraulic pressure chamber. Lung volume and...

Weddell seals are polar predators that must partition their time between many behaviours, including hunting prey at depth and breathing at the surface. Although they have been well studied, little is known about how foraging behaviour changes when access to breathing holes is restricted, such as in the isolated-hole paradigm. The current study took advantage of previously gathered data for seal...

Northern Elephant Seal Skin Disease (NESSD) is a severe, ulcerative, skin condition of unknown cause affecting primarily yearling northern elephant seals (Mirounga angustirostris); it has been associated with decreased levels of circulating thyroxine (T4) and triiodothyronine (T3). Abnormalities of the thyroid gland that result in decreased hormone levels (hypothyroidism) can result in hair los...

Concentrations of alternative flame retardants and polybrominated diphenyl ethers (PBDEs) were analyzed in ringed seal (Phoca hispida) blubber collected across the Canadian Arctic during subsistence hunts between 1998 and 2013. More than 80% of sampled animals were females and juvenile males. The highest mean ΣPBDE concentrations (sum of 13 congeners) were found in seals from Nain (Nunatsiavut)...

Synopsis Foraging by large (425 kg), mammalian carnivores often entails cryptic tactics to surreptitiously locate and overcome highly mobile prey. Many forms of intermittent locomotion from stroke-and-glide maneuvers by marine mammals to sneak-and-pounce behaviors by terrestrial canids, ursids, and felids are involved. While affording proximity to vigilant prey, these tactics are also associate...