Relationships between predator control and community composition of mammalian carnivores in central Spain: preliminary results

Abstract

The conservation of predator populations may have additional problems when their prey are of economic value, such as game species. Among Spanish hunters, Iberian mammalian carnivores have traditionally been considered as a limiting factor for game populations, being systematically killed to protect these populations. In spite of this, many aspects regarding mammalian carnivores control are still unknown. We aimed to evaluate the effect of hunting management, especially predator control, on the composition of the communities of mammalian carnivores, their abundance and inter-specific relationships in central Spain. Between 2010 and 2011, we surveyed three pairs of small game hunting estates (1475-4992 ha), each pair with similar land use composition but with differences in the use of predator control. Predator culling was a component of small game management in one estate of each pair, whereas no predator control was undertaken in the other estate. Information about predator control was gathered through interviews with game managers. Because mammalian carnivore species are usually scarce, elusive and nocturnal, traditional census methods, such as direct counts, are not useful to survey most of the species. Therefore, it is necessary to use alternative methods to accurately assess the composition of mammalian carnivore communities. We used a combination of three different methods: sign surveys based on faeces detection, camera-trapping and spotlight counts. Valerian-extract solution and Iberian lynx (Lynx pardinus) urine were employed for attracting carnivores to camera-traps. We recorded a total of eight carnivore mammal species during the study by at least one of the three methods employed. Red fox (Vulpes vulpes) was recorded in all hunting areas and common weasel (Mustela nivalis) in three of them. The other species were relatively rare in our study areas. European wildcat (Felis silvestris), Egyptian mongoose (Herpestes ichneumon) and Eurasian otter (Lutra lutra) were identified in only one hunting estate, and stone marten (Martes foina), Eurasian badger (Meles meles) and genet (Genetta genetta) in two areas. According to the camera-trapping methods, foxes were more abundant in areas with no predator control than in predator control areas in two of the three pairs of hunting estates. On the other hand, the number of species detected differed among the three methods considered. In this sense, the highest richness values were found for camera-trapping. The results confirmed the value of using these three complementary methodologies, especially camera-trapping, for studying elusive mammalian carnivores and obtaining useful information on the presence and abundance of these species. So far, the number of studied areas is still low to draw firm conclusions and we will increase the sampling size in the following years to determine the effects of hunting management, especially predator control measures, on Iberian carnivore communities.