The feeding habits of the stone marten (Martes foina) were studied by scat analysis in a village (n = 423 samples) and its surrounding agricultural environment (n= 572), during a six-year study (three periods), in southwest Hungary. Birds (relative frequency 20%, mainly small perching birds) and plants (35%, mainly orchard fruit) were the most important foods for the martens living in the village. Small mammals (29%, mainly voles) and plants (34%, mainly fruit) were the main food resources for the stone martens living in the agricultural environment. With respect to diet composition environment-dependent difference proved significant, but intra-environment difference did not. In comparison with those living in the agricultural environment the stone martens studied living in the village consumed more frequently: 1) heavier prey (greater consumption of domestic animals), 2) arboreal prey (e.g. birds) and 3) prey associated with human settlements (e.g. house mouse, house sparrow, domestic animals).
Low detectability of small nocturnal carnivores and biases associated to different census methods hamper the interpretation and reliability of the results of censuses and habitat studies of many cryptic and elusive species, especially because of false-negatives and/or lack of negatives. In order to overcome this problem, methodologies based on the use of presence-only data have been used to predict distribution of species. In this paper, we used presence data of two abundant nocturnal carnivores to test for segregation in their habitat. We compared niche overlap between the common genet and the stone marten at two different spatial scales, home range scale and landscape scale, through logistic regression analyses using presence-only data from Biscay, an area in which both species are common and widespread. We found great niche overlap at both spatial scales, but in spite of it logistic regression analyses found statistically significant differences in the predictor values of some variables. Habitat of genets and stone marten was differentiated by areas with dense vegetation that were of importance for genets, and open areas that were characteristic of stone marten habitat. We suggest that competition between the two species causes the observed segregation.