Essential fatty acids: Their impact on free-living alpine marmots (Marmotamarmota)

Previous laboratory studies demonstrated profound effects of dietary linole ic acid, a polyunsaturated fatty;acid (PUFA), on hibernation patterns in ro dents. We investigated PUFA composition in white adipose tissue (WAT), and possible influences of PUFAs on hibernation in free-living alpine marmots ( Marmota marmota). Our results show considerable seasonal and regional varia tion in WAT fatty acid composition, as well as differences between adipose tissue sites. Further, hibernation body mass loss decreased as WAT linoleic acid content increased. Attenuated winter mass-loss in marmots with high d ietary linoleic acid uptake appeared to be partly due to lowered mean gradi ents of body to ambient temperatures during deep hibernation. We conclude t hat local variability in dietary PUFA availability may be high enough to re sult in significant energetic consequences for free-ranging hibernators.