Food transit times in captive leopard seals (Hydrurga leptonyx)
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The passage rate of food through the alimentary tract of three captive, female leopard seals (Hydrurga leptonyx) was assessed. Seals were housed during winter in holding pools with access to water to reduce factors affecting digestion. Three different marker types were used; large and small beads and TiO2. Animals were checked hourly, and sample collections continued for 270 h after dosing. Individual differences in transit and mean retention times were observed, possibly reflecting inter-digestive emptying times of the stomach and small intestine. Age differences and activity levels may also have been a factor. Leopard seals displayed extended food transit times similar to terrestrial carnivores instead of other pinnipeds. This result suggests an adaptation of digestive system to cope with the opportunistic diet and range of prey types consumed.
KeywordsBeads Complex diet Extended Passage rate Poisson distribution TiO2
This project was approved by the Animal Care and Ethics Committee of the Zoological Parks Board of NSW. The authors would like to thank the following; the members of the Marine Mammal Department, Zoological Parks Board of NSW, especially A. Barnes who assisted with the sample collection, S. Pickering, Pet Porpoise Pool, Coffs Harbour for organising the trials and collecting the data, K. Collins for assistance with the sample preparation and I. van Ekris and A. Trube from the Veterinary Faculty, University of Sydney who provided advice and assistance with the spectrometry. J. Forcada and R. Casaux provided comments which greatly improved the manuscript. A Hall provided statistical advice, and funding was provided by the Winifred Scot Foundation.
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