Fur seal populations facilitate establishment of exotic vascular plants
نویسندگان
چکیده
منابع مشابه
Fur Seal Investigations, 1995
Counts of adult male northern fur seals (Callorhinus ursinus) are obtained each year on St. Paul Island and semi-annually on St. George Island as a factor of population monitoring. In 1995, counts were obtained from 11 to 16 July. A total of 5,154 harem and 8,459 idle adult male seals were counted on St. Paul Island. On St. George Island a total of 1,242 harem and 1,054 idle adult males were co...
متن کاملThe oldest known fur seal.
The poorly known fossil record of fur seals and sea lions (Otariidae) does not reflect their current diversity and widespread abundance. This limited fossil record contrasts with the more complete fossil records of other pinnipeds such as walruses (Odobenidae). The oldest known otariids appear 5-6 Ma after the earliest odobenids, and the remarkably derived craniodental morphology of otariids of...
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Resul ts of tests in 1946 showed the apparent vi tamin A potency of oil from livers of Alaskan bachelor seals to vary from 13,105 to 394,145 spec. units per gram of oil with an average value of 112,000. The oil content of livers varied from 0.20 to 2.17 percent by weight. The oil from carcass and blubber contained from 490 to 2,040 spec. uni ts of vi tamiri A per gram of oil.
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Previously unresolved problems in the populations studies of the Pribilof fur seal are reviewed. The tagging estimates of fur seal pups may have been biased by tag mortality and hence the apparent year class fluctuations after 1952 may be unreal. A set of cumulative estimates are given for the number of pups born in each year since 1950. These cumulative estimates depend on the estimate of the ...
متن کاملBrightness discrimination in the South African fur seal (Arctocephalus pusillus)
Underwater, the contrast between object and background is much larger reduced with increasing distance between object and observer than in air. For marine predators, such as pinnipeds, it would therefore be advantageous to possess a high sensitivity for brightness differences, since this would increase the distance at which prey can be detected visually. Few studies have examined the brightness...
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ژورنال
عنوان ژورنال: Biological Conservation
سال: 2013
ISSN: 0006-3207
DOI: 10.1016/j.biocon.2013.03.024