SUMMER FOOD NICHE COMPARISON BETWEEN THE RED FOX AND GENUS MARTES IN MOUNTAIN HABITATS
PETAR PETROV*, ELITSA POPOVA, DIANA ZLATANOVA
Department of Zoology and Anthropology, Faculty of Biology, Sofia University
“St. Kliment Ohridski”, Sofia, Bulgaria
*Corresponding author: zlite2@mail.bg
Keywords: food niche, red fox, martens Martes
Abstract: The red fox Vulpes vulpes and the two species from genus Martes (the Stone marten Martes foina and the Beech marten Martes martes) inhabit common habitats in Bulgaria, but their food preferences and competition are poorly studied.
In our study, we tried to evaluate their summer food preferences based on scat analyses of 139 martens’ scats and 151 fox scats from Rhodopi (West and East), Osogovo and Pirin mountains where species overlap their distribution. As the scats of the two martens are indistinguishable between each other, in our analyses, we considered the comparison of martens scats with the fox only on the genus’s level. This is a preliminary study of a larger research.
In the scats, we identified both plant and animal (invertebrate and vertebrate) components. The food niches in both genera are unexpectedly narrow, due to significant preferences to a limited number of food items. The biggest overlap of the food niche in summer in the three mountains is observed in rodents, insects, wild plums, blackberries, dog rose and juniper fruits. The fox in Western Rhodopi uses twice as many types of food (and has lesser overlapping in the food niche) than martens and almost equal number in Osogovo and Pirin. 14 scats of fox from East Rhodopi, Osogovo and Pirin and 1 of Martes from Osogovo contained garbage (plastic, nylon and even glass). Other anthropogenic foods (tomato, cucumber and pepper) were also found.