Liebsch, NS et al. (2007): Dive track profile, intermandibular angel sensor profile and immobilisation data of adult female Weddell seals at Drescher Inlet from expedition DRE2003. doi:10.1594/PANGAEA.603115, Supplement to:Liebsch, Nikolai S; Wilson, Rory P; Bornemann, Horst; Adelung, Dieter; Plötz, Joachim (2007): Mouthing off about fish capture: Jaw movement in pinnipeds reveal the real secrets of ingestion. Deep Sea Research Part II: Topical Studies in Oceanography, 54(3-4), 256-269, doi:10.1016/j.dsr2.2006.11.014
Determination of when and where animals feed and how much they consume is fundamental to understand their ecology and role in ecosystems. However, the lack of reliable data on feeding habits of wild animals, and particularly in marine endotherms, attests to the difficulty in doing this. A promising recent development proposes using a Hall sensor-magnet System - the inter-mandibular angle sensor (IMASEN) attached to animals' jaws to elucidate feeding events. We conducted trials on captive pinnipeds by feeding IMASEN-equipped animals with prey to examine the utility of this system. Most feeding events were clearly distinguishable from other jaw movements; only small prey items might not be resolved adequately. Based on the results of this study we examined feeding events from free-ranging Weddell seals fitted with IMASENs and dead-reckoners during December 2003 at Drescher Inlet (Riiser Larsen Ice Shelf, eastern Weddell Sea coast), and present data on prey capture and ingestion in relation to the three-dimensionalmovement patterns of the seals. A total of 19 Weddell seals were immobilised by using a combination of ketamine, xylazine, and diazepam. Eight seals were drugged once, six two times, and two and three were drugged three and four times each, coming to a total of 38 immobilisation procedures. Narcoses were terminated with yohimbine (doi:10.1594/PANGAEA.438931).
Liebsch, Nikolai S (2006): Hankering back to ancestral pasts: constraints on two pinnipeds, Phoca vitulina & Leptonychotes weddellii foraging from a central place. PhD Thesis, Mathematisch-Naturwissenschaftliche Fakultät der Christian-Albrechts-Universität zu Kiel, 161 pp, urn:nbn:de:gbv:8-diss-18606
Plötz, Joachim; Bornemann, Horst; Liebsch, Nikolai S; Watanabe, Yuuki (2005): Foraging ecology of Weddell seals. In: Arntz, WE & Brey, T (2005): The Expedition ANTARKTIS XXI/2 (Bendex) of RV Polarstern in 2003/2004, Reports on Polar and Marine Research, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, 503, 63-67, hdl:10013/epic.22773.d001