title: Cooling rates and body temperature regulation of hibernating echidnas (Tachyglossus aculeatus).
abstract: Echidnas (Tachyglossus aculeatus) are amongst the largest deep hibernators, but it is difficult to get them to hibernate normally under laboratory conditions. We measured body temperature (Tb) in 14 free-ranging echidnas using implanted data-loggers. Cooling during entry into hibernation bouts followed a Newtonian cooling curve, and conductances calculated from cooling curves were identical to those observed in cold exposed euthermic echidnas. Comparison with a reference soil temperature demonstrated that echidnas showed behavioural thermoregulation during hibernation; early in the hibernation season echidnas preferred to hibernate in cool areas, while during the coldest months they moved to warmer hibernacula, giving a preferred Tb in the range 8-10 degrees C. Thermal buffering against excessive variation in Tb may be as important as maintaining a low Tb.
authors.affiliation: School of Zoology, University of Tasmania, Private Bag 5, Hobart, Tasmania, 7001, Australia. s.c.nicol@utas.edu.au
authors.forename: Stewart C
authors.initials: SC
authors.lastname: Nicol
authors.forename: Niels A
authors.initials: NA
authors.lastname: Andersen
mesh_terms: D000818:Animals; D001833:Body Temperature Regulation / Q000502:physiology*; D005260:Female; D006605:Hibernation / Q000502:physiology*; D008297:Male; D004442:Tachyglossidae / Q000502:physiology*; D013648:Tasmania; D013696:Temperature