Relationships between Stone Martens, Genets and Cork Oak Woodlands in Portugal

Abstract

Although the stone marten (Martes foina) is widely distributed in Europe, little is known about its ecological and spatial requirements. Using radiotelemetry and food habits, we investigated the use of cork oak (Quercus suber) woodlands by an unharvested population of stone martens in SW Portugal. We also evaluated spatial ecology and food habits of the common genet, (Genetta genetta), and its niche overlap with stone martens. Home range size (minimum convex polygon) of martens (n=5) and genets (n=7) averaged 2.6 and 3.3 km 2 , respectively. Variation in home range area during the year was associated with breeding activities. Tolerance among stone martens and genets was greater than between conspecifics of the same sex. Both stone martens and genets were nocturnal and used riparian vegetation and cultivated fields more than expected. However, genets also used oak woodland more than expected for foraging and resting. Stone martens and genets used similar rest sites. The seasonal variation in resource exploitation by stone martens (58 scats) and genets (75 scats) followed the same pattern. However, in summer and autumn, genets ate more crayfish (Procambarus clarkii) and mammals, while stone martens ate more fruits. Despite similarities in habitat utilization and food habits, core areas of both species were mutually exclusive, thus suggesting the existence of some present or past interspecific interaction. This study suggests that, except for resting, stone martens do not depend on cork oak trees and its products for existence. However, intensive destruction of understory cover and riparian corridors might alter use of cork oak trees by stone martens and their interspecific interactions with genets.