Rust-Colored Bearded (Erignathus barbatus) and Ringed (Phoca hispida) Seals from Svalbard, Norway

Lydersen, C.; Kovacs, K. M.; Lydersen, E.

doi:10.1093/jmammal/82.1.225

Cited by 1 publication

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“…However, during the past decade concerted efforts have greatly increased our knowledge of bearded seal natural history, and their importance to arctic ecosystems (e.g. Hammill et al, 1994; Lydersen Kovacs et al, 1996;Lydersen et al, 1996;Andersen et al, 1999;Lydersen and Kovacs, 1999;Gjertz et al, 2000;Krafft et al, 2000;Lydersen et al, 2001;Marshall et al, 2001;Van Parijs et al, 2001;Lydersen et al, 2002;Van Parijs et al, 2003;Van Parijs et al, 2004;Davies et al, 2006;Marshall et al, 2006;Van Parijs and Clark, 2006;Dehn et al, 2007;Risch et al, 2007). Analyses of stomach contents and recent stable isotope analyses demonstrate that bearded seals are generalist foragers (e.g.…”

Section: Introductionmentioning

confidence: 99%

Feeding kinematics, suction and hydraulic jetting capabilities in bearded seals (Erignathus barbatus)

Marshall

Kovacs

Lydersen

2008

Journal of Experimental Biology

147

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SUMMARYFeeding kinematics, suction and hydraulic jetting capabilities of bearded seals (Erignathus barbatus) were characterized during controlled feeding trials. Feeding trials were conducted both on land and in water, and allowed a choice between suction and biting, but food was also presented that could be ingested by suction alone. Four feeding phases, preparatory, jaw opening, hyoid depression and jaw closing were observed; the mean feeding cycle duration was 0.54±0.22·s, regardless of feeding mode (P>0.05). Subjects feeding on land used biting and suction 89.3% and 10.7% of the time, respectively. Subjects feeding in water used suction and hydraulic jetting 96.3% and 3.7% of the time, respectively. No biting behavior was observed underwater. Suction feeding was characterized by a small gape (2.7±0.85·cm), small gape angle (24.4±8.13°), pursing of the rostral lips to form a circular aperture, and pursing of the lateral lips to occlude lateral gape. Biting was characterized by large gape (7.3±2.2·cm), large gape angle (41.7±15.2°), and lip curling to expose the teeth. An excavation behavior in which suction and hydraulic jetting were alternated was used to extract food from recessed wells. The maximum subambient and suprambient pressures recorded were 91.2 and 53.4·kPa, respectively. The inclusion of suction data for phocids broadens the principle that suction feeding kinematics is conserved among aquatic vertebrates. Furthermore, bearded seals support predictions that mouth size, fluid flow speed, and elusiveness of prey consumed are among a suite of traits that determine the specific nature of suction feeding among species.

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