Daily activity and body temperature of the southern woodchuck, Marmota monax monax, in northwestern Arkansas [Activité journalière et température corporelle de la marmotte du sud, Marmota m. monax, dans le nord de l'Arkansas].

Résumé

Observations faites en été et en automne l'activité en surface occupe 35,4% du temps, elle se déroule selon un cyle bimodal (mai-juin) octobre novembre) ou unimodal (juin-septembre). Dans le deuxième cas, l'activité souterraine atteint 51,6% contre 37,9% dans le premier cas. La température du corps évolue, elle aussi, cycliquement avec des variations journamlières et saisonnières. Les effets des conditions du milieu sur ces paramètres sont peu importants. Daily activity and body temperature cycles of Marmota monax monax were studied in northwestern Arkansas during the summer and autumn of 1973. Above ground activity was observed 35.4 percent of the time. A unimodal cycle was characteristic of activity from 1 May through 14 June and 1 October through 19 November, whereas a bimodal cycle described activity from 15 June through 30 September. During the unimodal activity pattern, below ground activity accounted for 51.6 percent of the total activity as compared to 37.9 percent in the bimodal condition. Early morning and afternoon activity was greatest during the midsummer period, with depressed activity between 1300 and 1600 hours. Although body temperature cycles were slight during all periods, the cycle amplitude was largest early and late in the year. Maximum daily body temperatures were recorded during the day, whereas minimum body temperature occurred at night. The mean body temperature was 37.8±0.57°C. Body temperatures averaged 0.5°C lower during early summer and autumn than during midsummer. Effects of environmental variables on animal activity, position, and body temperature were slight.