Activity patterns of radio-tracked weasels Mustela nivalis in Białowieża National Park (E Poland)

• Published in: Annales zoologici fennici 2000-01, Vol.37 (3), p.161-168
• Main Authors: Jędrzejewski, Włodzimierz, Jędrzejewska, Bogumiła, Zub, Karol, Nowakowski, Wojciech K.
• Format: Article
• Language: English
• Subjects: Ambient temperature; Biology; Deciduous forests; Mustela nivalis; National parks; Poland; Predation; Rodents; Seasons; Voles; Weasels; Woodlands
• ISSN: 0003-455X; 1797-2450

Diel activity rhythms and factors affecting the duration of daily activity were studied in nine male common weasels Mustela nivalis vulgaris, radio-tracked in the pristine deciduous woodland in eastern Poland from April 1990 to August 1991. During the study, mean daily temperature varied from -5.3 °C to 25.5 °C, and densities of forest rodents (bank voles Clethrionomys glareolus and yellow-necked mice Apodemus flavicollis) ranged from 2 to 270 ind. ha-1. Weasels showed clearly diurnal activity, with a peak around 1000—1300 hrs. On average, weasels were active for 3.8 h day-1 (SE = 0.3, range 0—14 h day-1), with 0 to 7 bouts of activity (mean 2.1, SE = 0.1), each bout lasting, on average, 1.8 h (SE = 0.1). Spells of activity were separated by short inactivity bouts (on average 2 h, SE = 0.2). Long (nocturnal) inactivity lasted, on average 17.5 h day-1 (SE = 0.7). A remarkable seasonal variation in the duration of weasel daily activity and number of activity bouts per day was related to changes in ambient temperature. In winter, weasels were active in 1—2 bouts day-1 each bout lasting 1—2 h; whereas in summer they showed 3—4 (maximally 7) bouts of activity. The highest level of activity coincided with the mating season. Fluctuations of rodent numbers had little effect on weasel activity pattern.