title: Thermoregulatory adaptations of the overwintering captive raccoon dog (Nyctereutes procyonoides) in boreal climate.
abstract: The raccoon dog (Nyctereutes procyonoides) is a nocturnal canid thought to utilise passive wintering strategy in the boreal climate. To record the deep body temperature (T(b)), 12 farmed raccoon dogs were implanted with intra-abdominal T(b) loggers on November 26, 2003. Between December 3, 2003 and January 27, 2004 half of the animals were fasted for 8 weeks. The amplitude of the diurnal T(b) oscillations increased due to fasting. However, the mean diurnal T(b) was lower in the fasted animals only during two occasions. Unlike observed previously in other species, not only did the raccoon dogs experience hypothermia between 0600 and 1000 hr but also hyperthermia between noon and 1800 hr. The fasted animals were as active as the fed animals measured after 42-43 days of fasting and there was a significant cross-correlation between physical activity and T(b). The nocturnal period of hypothermia is probably an adaptation to save energy during food deprivation. The diurnal hyperthermia could be explained by the opportunistic foraging behaviour of the species. Opposite to the established assumptions, the raccoon dog does not seem to enter winter sleep on fur farms. In the future it is important to determine if true winter sleep occurs in nature in the species.
authors.affiliation: Department of Biology, University of Joensuu, FIN-80101 Joensuu, Finland. pniemine@cc.joensuu.fi
authors.forename: Petteri
authors.initials: P
authors.lastname: Nieminen
authors.forename: Esa
authors.initials: E
authors.lastname: Hohtola
authors.forename: Teija
authors.initials: T
authors.lastname: Pyykönen
authors.forename: Tommi
authors.initials: T
authors.lastname: Paakkonen
authors.forename: Jari
authors.initials: J
authors.lastname: Aho
authors.forename: Martina
authors.initials: M
authors.lastname: Cittová-Kontu
authors.forename: Juha
authors.initials: J
authors.lastname: Asikainen
authors.forename: Jaakko
authors.initials: J
authors.lastname: Mononen
authors.forename: Anne-Mari
authors.initials: AM
authors.lastname: Mustonen
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D001833:Body Temperature Regulation / Q000502:physiology*; D001835:Body Weight; D002980:Climate; D003080:Cold Temperature; D005260:Female; D005508:Food Deprivation; D046031:Raccoon Dogs / Q000502:physiology*; D012621:Seasons