California Sea Lions Use Dolphins to Locate Food
نویسنده
چکیده
Aggregations by 3 species of dolphins (the bottlenose dolphin [Tursiops truncatus], the short-beaked common dolphin [Delphinus delphis], and the long-beaked common dolphin [Delphinus capensis]) and California sea lions (Zalophus californianus) were investigated in Santa Monica Bay, California. Groups were followed and observed during 201 boat-based surveys conducted in 1997–2001 documenting that sea lions were aggregated in 18.6% of the sightings with bottlenose dolphins (150 bottlenose dolphin sightings) and in 45.9% of the sightings with 1 of the 2 species of common dolphins (98 common dolphin sightings). Aggregations of bottlenose dolphins and sea lions were observed in inshore (,500 m from shore) and offshore (.500 m) waters, whereas common dolphins and sea lions were observed only in offshore waters. These aggregations were often recorded feeding near escarpments and submarine canyons, showing a striking preference for these bathymetric features. The results show that sea lions spend a significant amount of time following dolphins, sea lions initiate aggregation and departure from dolphin schools, these aggregations occur more often than is expected by chance, and no aggressive behavior between sea lions and dolphins was ever observed at or near the surface. I argue that sea lions may take advantage of the superior food-locating abilities of dolphins. This paper provides the 1st detailed description of mixed-species aggregations and habitat usage by 3 dolphin species and sea lions.
منابع مشابه
Risk factors associated with development of poxvirus lesions in hospitalized California sea lions.
OBJECTIVE To identify risk factors that may predispose California sea lions (Zalophus californianus) to development of cutaneous poxvirus nodules during hospitalization in a rehabilitation center. DESIGN Retrospective case-control study. ANIMALS 90 California sea lions admitted to a rehabilitation center. PROCEDURE Hospital records of 275 stranded California sea lions admitted to the reha...
متن کاملCorrection to ‘Food limitation of sea lion pups and the decline of forage off central and southern California’
California sea lions increased from approximately 50 000 to 340 000 animals in the last 40 years, and their pups are starving and stranding on beaches in southern California, raising questions about the adequacy of their food supply. We investigated whether the declining sea lion pup weight at San Miguel rookery was associated with changes in abundance and quality of sardine, anchovy, rockfish ...
متن کاملSentinel California sea lions provide insight into legacy organochlorine exposure trends and their association with cancer and infectious disease
BACKGROUND Organochlorine contaminants (OCs), like polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethanes (DDTs), are widespread marine pollutants resulting from massive historical use and environmental persistence. Exposure to and health effects of these OCs in the marine environment may be examined by studying California sea lions (Zalophus californianus), which are long lived,...
متن کاملAssociation between Positive Canine Heartworm (dirofilaria Immitis) Antigen Results and Presence of Acanthocheilonema Odendhali Microfilaria in California Sea Lions (zalophus Californianus).
This study establishes a relationship between positive canine heartworm (Dirofilaria immitis) test results frequently observed in California sea lions (Zalophus californianus) and infection with the filarid nematode Acanthocheilonema odendhali. Four commercially available canine heartworm antigen tests were evaluated for cross-reaction with A. odendhali in California sea lions. Sera were tested...
متن کاملSensing Habitat Use by Ice-associated Seals; from Dog Noses to Satellite Observations
Extant marine mammals represent multiple recolonizations of the marine environment by terrestrial mammals. Freed from the constraints of terrestrial locomotion, cetaceans (whales, dolphins, and porpoises) and pinnipeds (seals, sea lions, and walruses) diversified and spread throughout the world’s oceans. For those animals, land masses represented barriers, and their evolutionary history has bee...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2006