Habitat use and selection of 14 Alpine ibex males were studied in the Gran Paradiso National Park. Alpine meadows were always overused and positively selected, because this habitat constituted an important food resource for the ibex. Even if rocks (30%) and stone ravines (22%) were the most frequented habitats in the study area, their use was lower than their availability because they offered few trophic resources. Pastures were used only in spring when the ibexes were looking for those sites just free from snow and with fresh vegetation. Stone ravines, where the ibexes rested in the hottest days, were most used in summer. Rocks were most used in winter: rock-faces are the only sites where the risk of avalanches is low and where it is still possible to find snow-free patches. Larch woods were especially used in winter and spring when it was still possible to find snow-free patches. The home range sizes proved to be influenced by the amount of Alpine meadows and rocks.
The leg bone marrow fat of 11 roe deer (Capreolus capreolus) killed by wolves (Canis lupus) was examined and compared with that of 15 roe deer killed in traffic accidents. Moreover, a sample of 14 red deer (Cervus elaphus) kills was examined. High levels of femur marrow fat (75–100 %) were detected in 45% of the roe deer killed by wolves. The amount of leg bone marrow fat showed a decrease through the winter season, roe deer killed by wolves did not show a significantly lower marrow fat level than those killed in traffic accidents. According to our analyses red deer were in generally poor conditions, and yet such a result cannot be regarded as representative of the average condition of the population.
The aim of this study is to evaluate how wolves affected the prey community in a newly recolonization area of the Western Alps, the Gran Paradiso National Park (GPNP). Since 1960’s, this portion of the Alps hosts a multi-specific wild ungulate community. It lived in absence of large predators for more than a century. In 2006 a couple of wolves re-established in GPNP and in summer 2007 the first reproduction was documented. The present study was conducted during the following two years. In term of biomass
consumed (Bio%), Alpine chamois was the main prey of wolves in all seasons (Bio% Summer 2007 = 70.13; Bio% Winter 2007/2008 = 56.99; Bio%Summer 2008 = 67.52; Bio% Winter 2008/2009 = 36.35), while roe deer were intensely consumed during the adverse season (Bio% W2007/2008
= 23.05 %; Bio% W2008/2009 = 42.47 %). Although cervids were much less abundant than bovids in the area, they represented one of the main
food items of wolves, possibly because of the strong habitat overlap and altitude use between predator and preys. Moreover, the minor adaptation of cervids to the Alpine environment compared to bovids could affect their vulnerability and thus the respective consumption of the different species during the adverse season.