Activity patterns of the stone marten <em>Martes foina</em> Erxleben, 1777, in relation to some environmental factors

Abstract

Three stone martens (2 males, 1 female) Martes foina Erxlebcn, 1777, were radio-tracked for 4, 2.5 and 12 months respectively, in a rural hilly area in Siena County, Central Italy. Food habits were assessed by faecal analysis, as pcrccnlagc of occurrence and estimated volume. Diel, nocturnal, diurnal and crepuscular activity were mcasured as the proportion of active fixes on a 48 houdfortnight basis. Scasonal variation of all activities was assessed and correlated to mean T'C, daylcngth, food and trophic niche breadth. Daily time budgets were also measured and compared between months and seasons. Fruits were the staple food in summer/autumn, followed by vcrtcbratcs and invertebrates. Vertebrates and invertebrates were the main food source in winter and spring. No significant difference of activity could be found between the three animals. Diel activity reached its maximum in summer, and decreased significantly throughout the rest of the ycar. Die1 activity did not differ significantly between subsequent seasons, whereas a statistically significant difference was found between every other season. Nocturnal activity peaked in winter and dropped in summer. It significantly differed between seasons but for spring vs. summer and autumn vs. winter. Diurnal activity differed significantly between seasons, but for spring vs. summer, when it reached its maximum, and for autumn vs. winter when it was at its minimum. Crepuscular activity remained constant throughout the year. The 24-hour distribution of active fixes showed a bimodal pattern in spring and summer, while in autumn and winter thc activity pattern was unimodal, with a nocturnal peak. Time budget differed between seasons, but (or autumn and winter vs. spring. Significant correlations between activities and abiotical variables (except rainfall) were direct, but for nocturnal activity. No significant correlation was found with precipitation. Activity was not significantly correlated to any food category, except reptiles, a spring and summer prey. Coleoptera and Orthoptera, the main invertebrate food, and fruits, correlated poorly to activity. Surprisingly, food does not seem to be the primary factor responsible for variation in activity patterns.