Meeting Abstract
Sleep loss is well known to impair cognitive function, immunological responses, and general well-being in humans. However, sleep requirements in mammals and birds may vary dramatically, especially with changes in environment. In circumpolar regions with continuous light, sleep requirements may be little, particularly in breeding birds. The effects of sleep loss on several fitness parameters were examined in two species of Arctic-breeding passerine birds: Lapland longspurs (Calcarius lapponicus) and snow buntings (Plectrophenax nivalis). Adult males were implanted during the nestling phase (4 days post-hatch) with osmotic pumps containing an anti-narcolepsy drug, modafinil, to induce sleep loss for 72 h. We measured nestling weights on day 2 and day 7 following hatching. In addition, we conducted 1 h observations of nestling feeding rates on day 6 post-hatch. Recent data show that adults undergo a 4-5 h quiescent period between 0000h and 0500h. We predicted that further inhibition of sleep may temporarily increase feeding rates, but eventually lead to decreased parental care and slower nestling development from birds needing to sleep after pharmacological inhibition. Alternatively, as high-arctic species are adapted to continuous light throughout their breeding season, mechanisms may exist that allow them to function normally despite loss of sleep.
