Chemical and carbon isotopic composition of fatty acids in adipose tissue as indicators of dietary history in wild arctic foxes (A lopex lagopus) on Svalbard

Abstract

With 1 figure in the text)The chemical and carbon isotope compositions of triacylglycerol fatty acids were analysed in samples from two or more adipose depots dissected from adult and subadult arctic foxes collected between November 1991 and March 1992 in four different areas of Spitsbergen in the Svalbard archipelago (latitude 78 5' to 79' 5O'N). Site-specific differences were minor but there were large and consistent differences in the fatty acid composition of the storage lipids of foxes caught in the same areas, suggesting that residents of contiguous territories may have had quite different diets. The adipose tissue of adult foxes caught in Austfjordneset, an area where reindeer are rare, contained a much greater proportion of unsaturated fatty acids, suggesting that these animals were feeding mainly in the marine ecosystem, probably on seabirds and/or fish in summer and the remains of polar bear kills in winter. Measurements of the relative abundance of the carbon isotopes I2C and 13C in individual fatty acids show that palmitoleic acid (C16: 1) in storage triacylglycerols originates from the marine food chain, probably together with most other unsaturated lipids, but that the foxes obtain oleic acid (C18: l), and probably most saturated fatty acids, from either terrestrial or marine sources.

Understanding the Nutritional Sources of Gastropods and Anomura from the Mangrove Forest of Weno Island, Micronesia

“…그러나 최근에 와서 이러한 지방산 먹이 추적자 중 일부는 기존에 알려진 바와 달리 때때로 상위 포식자로 전달/축적되는 과정에서 변형되거나, 특정 생물기원이 아닌 것으로 밝혀지고 있다 (Graeve et al 1994;Dalsgaard et al 2003;Ju and Harvey 2004). 더욱 이 지방산은 생체 내에서의 짧은 순환주기(일~주)로 장기 간의 먹이원을 대변하기에는 어려움이 있다 (Cook 1991;Pond et al 1995;Alfaro et al 2006 (Gu et al 1996;Vizzini et al 2002). 이뿐만 아니라, 맹그로브를 포함한 식물의 질소 안정동위원소 비 는 퇴적물에서의 식물과 미생물간 상호작용 및 질소 기원 등의 다양한 과정을 반영한다 (Dawson et al 2002) (Stoner and Zimmerman 1986;Newell et al 1995;Primavera 1996 (Bunn et al 1995).…”

Charles Elton’s Accounts of Expeditions from Oxford to the Arctic in the 1920s

“…The mountaineers in particular maintained impressive standards of physical fitness. Elton (1923) described searching for sanderling nests on Reindeer Peninsula, Liefdefjorden on 28 July 1923 by citing Longstaff's (1950) autobiography thus: "I had many walks over this tundra: the surface of the ground melts in high summer and the foot sinks into the mud at every depression. One day, with Charles Elton I walked for twelve hours, and doubt if we covered twenty-five miles…."…”

“…None was seen by us" (Summerhayes and Elton, 1923:221). Vulpes (formerly Alopex) lagopus is now widespread throughout the archipelago as general scavenger and predator, especially of nesting birds (Pond et al, 1995;Eide et al, 2005).…”

“…Contemporary enthusiasm for aviation and exploration prompted a popular book (Binney, 1925b) about the logistics, sledging, and seaplane of the 1924 expedition. Tom Longstaff (1950) briefly described his Arctic experiences in 1921 and 1923 in his memoirs, and they feature in various secondary accounts (e.g., Thompson, 1953).…”

Use of blubber fatty acid profiles to distinguish dietary differences between grey seals Halichoerus grypus from two UK breeding colonies

“…The technique has been used to distinguish between populdtions and/or dietary differences of several seal species (Ackman et al 1971, West et al 1979a, Grahl-Nielsen et al 1993, Kakela et al 1993, Smith et al 1996, Iverson e l al. 1997b, lobsters (Castell et al 1995), fish (Iverson et al 199713) and foxes (Pond et al 1995).…”