Fat indices of arctic foxes Alopex lagopus in Svalbard

© WILDLIFE BIOLOGY · 9:3 (2003) Fecundity in and survival of wild animals are strongly related to their fat content, which reflects availability and quality of food. In many temperate and arctic homeotherms, fat deposition in summer and autumn is crucial for their winter survival. Hence, techniques of estimating fat content of animals have been widely used in management of and research on wildlife populations. To obtain absolute figures of fat content by chemical extraction of lipid from a homogenate of the animal or by dissecting all visible adipose tissue is time consuming and expensive, and often not practicable. Indexing of fat content has therefore been widely used. On live specimens, the estimation of water content by dilution methods (e.g. Torbit, Carpenter, Alldredge & Swift 1985) which assumes a linear relationship with lipid content, and indices made by using body weight and one or more linear measurements (e.g. Cattet 1990, Ryg, Lydersen, Markussen, Smith & Øritsland 1990) are the most Fat indices of arctic foxes Alopex lagopus in Svalbard