Some aspects of the metabolism of hibernating and recently aroused common dormouse Muscardinus avellanarius L. (Rodentia, Gliridae)

Abstract

A dormouse found in hibernation in its winter nest on January 26 was studied continously from February 5 until May 11 by recording ambient temperature, temperatures inside the nest ball and 5 cm from it, and by recording any possible motor activity. The first emergence from hibernaculum occurred on April 3 after which the animal was active each day with the exception of April 11, 13 and 14. Activity mainly occurred during evening and night hours and lasted on average 4 hrs (2-8 hrs) per day. Outside periods of activity the winter nest was consistently used as a place of shelter and for sleep.The ambient temperature ranged from-0.5° to 21.0°C being chiefly 1°C less the nestbox temperature. The difference between the nest-box and nest temperature was also about 1°C when the animal was inactive, thus clearly indicating torpidity. Steep increases in nest temperature, amounting to 14-18°C and raising nest temperature up to 30°C, were recorded on four occasions. This is interpreted as shallow torpor, since no activity occurred on these days.The spontaneous warming up from deep hypothermia to shallow torpor lasted on average 40 min (30-70 min), while the duration of passive cooling when returning to the hypothermic condition amounted to 5 hrs. In the weeks following continuous hibernation the dormouse alternated between activity, shallow torpor, and relatively deep torpor each day. The species should be considered as a true aestivator.

Etude d'une population de Muscardins (Muscardinus avellanarius) lors du repos journalier (Mammalia, Gliridae)

“…La torpeur journalière durant l'été est très mal connue chez Muscardinus: Wachtendorf (1951) a trouvé un animal (parmi 59 observations durant un été) en torpeur le 18 septembre et Löhrl (1960) signale sans autres précisions qu'il a vu régulièrement au printemps et en automne des animaux en torpeur, lesquels avaient disparu du nichoir au prochain contrôle. Walhovd & Jensen (1976) ont suivi par enregistrement continu de la température du nid un Muscardin entre le 5 février et le 11 mai et ont observé que pendant trois jours (de 8 à 14 h. par jour à mi-avril) la température du nid équivalait la température externe; ils en ont déduit que leur animal effectuait trois torpeurs journalières consécutives.…”

The elusive winter engineers: structure and materials of hazel dormouse hibernation nests

“…Despite the limited amount of information on materials used for the construction of hibernation nests, previous studies have suggested that dormice use similar materials for the construction of both summer and hibernation nests (Juškaitis, 2014; Morris, 2004; Vogel & Frey, 1995; Walhovd & Jensen, 1976). Verbeylen et al.…”

“…petraea ), whilst Vogel and Frey (1995) reported wide use of beech leaves and occasionally grass blades in 10 hibernation nests. Other previous studies have focussed on their size, shape and thickness (Morris, 2004; Vogel, 1997; Walhovd & Jensen, 1976) but lacked detail of what materials are used. The scarcity of information on hibernation nests can be attributed to the fact that they are difficult to find and in most cases are only found incidentally.…”

Daily torpor in free-ranging common dormice (Muscardinus avellanarius) in Lithuania

“…Through torpor mammals maximise energy conservation during periods of cold stress or shortage of food and water (Perrin and Ridgard 1999). Many experimental studies of dormancy patterns in dormice (Gliridae) have been carried out in captivity, involving several species, e.g., common dormouse (Muscardinus avellanarius) (Tomilin 1958;Walhovd 1974;Walhovd and Jensen 1976), edible dormouse (Glis glis) (Ko¨nig 1960;Wilz and Heldmaier 2000), garden dormouse (Eliomys quercinus) (Pajunen 1970(Pajunen , 1984, African woodland dormouse (Graphiurus murinus) (Webb and Skinner 1996), spectacled dormouse (Graphiurus ocularis) (Perrin and Ridgard 1999). Additionally Vogel (1997) presented a comparative study of hibernation in three dormouse species.…”