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Prey capture and processing behaviors vary with prey size and shape in Australian and subantarctic fur seals
Author(s) -
Hocking David P.,
Fitzgerald Erich M. G.,
Salverson Marcia,
Evans Alistair R.
Publication year - 2016
Publication title -
marine mammal science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.723
H-Index - 78
eISSN - 1748-7692
pISSN - 0824-0469
DOI - 10.1111/mms.12285
Subject(s) - predation , fur seal , foraging , biology , range (aeronautics) , sea lion , biting , zoology , fish <actinopterygii> , ecology , fishery , materials science , composite material
When hunting at sea, pinnipeds should adapt their foraging behaviors to suit the prey they are targeting. We performed captive feeding trials with two species of otariid seal, Australian fur seals ( Arctocephalus pusillus doriferus ) and subantarctic fur seals ( Arctocephalus tropicalis ). This allowed us to record detailed observations of how their foraging behaviors vary when presented with prey items that cover the full range of body shapes and sizes encountered in the wild. Small prey were captured using suction alone, while larger prey items were caught in the teeth using raptorial biting. Small fish and long skinny prey items could then be swallowed whole or processed by shaking, while all prey items with body depths greater than 7.5 cm were processed by shaking at the water's surface. This matched opportunistic observations of feeding in wild Australian fur seals. Use of “shake feeding” as the main prey processing tactic also matches predictions that this method would be one of the only tactics available to aquatic tetrapods that are unable to secure prey using their forelimbs.