No abstract

Individual identification was assessed for 30 brown bears (Ursus arctos) from the endangered Apennine population in central Italy, mostly through non-invasive sampling. Shed hairs were used as a source of DNA to obtain single genotype profiling at 12 microsatellite loci. Average expected heterozygosity (0.438) and mean number of alleles per locus (2.2) showed that the level of genetic diversity was one of the lowest recorded for brown bear populations across their European and North American ranges. A large portion of the original genetic variation may have been lost through random genetic drift during the recent period of isolation. The level of genetic variability proved sufficient to identify the bears individually by using nine microsatellite loci. The probability that two animals shared by chance the same multilocus genotype was estimated to be 1 in 100. Despite the recent history of small population size, the average relatedness indicated that the majority of individuals are not first-order relatives. Simulated paternity tests showed that a 12-loci genotype may be necessary to assign paternity with an 80-95% confidence level. Lack of genetic diversity, as well as the maintenance of an adequately effective number, may seriously jeopardise the long-term survival of this population. Furthermore, high mortality rates, poaching and encroachment by human activities represent immediate, urgent concerns. A population increase through enforced protection and habitat restoration is recommended. Presently, restocking with bears from other source populations should be discouraged to avoid genetic extinction. Non-invasive sampling provided reliable population and individual genetic data. Microsatellite genotyping proved a valuable genetic tagging method and a feasible alternative to conventional field counts for the brown bear in central Italy.

No abstract

Specialization is typically inferred at population and species level but in the last decade many authors highlighted this trait at the individual level, finding that generalist populations can be composed by both generalist and specialist individual. Despite hundreds of reported cases of individual specialization there is a complete lack of information on inter-individual diet variation in specialist species. We studied the diet of the Italian endemic Spectacled Salamander (Salamandrina perspicillata), in a temperate forest ecosystem, to disclose the realised trophic niche, prey selection strategy in function of phenotypic variation and inter-individual diet variation. Our results showed that Salamandrina is highly specialized on Collembola and the more specialized individuals are the better performing ones. Analyses of inter-individual diet variation showed that a subset of animals exhibited a broader trophic niche, adopting different foraging strategies. Our findings reflects the optimal foraging theory both at population and individual level, since animals in better physiological conditions are able to exploit the most profitable prey, suggesting that the two coexisting strategies are not equivalent. At last this species, feeding on decomposers of litter detritus, could play a key role determining litter retention rate, nutrient cycle and carbon sequestration.

Ranging behaviour and habitat selection of 23 male and 6 female adult (5-10 years old) Alpine chamois Rupicapra rupicapra (Linnaeus 1758) were monitored from February 2000 to December 2002, in an area of the Western Alps. The chamois were radio-located for a minimum of 4 and a maximum of 35 months, until failure of radio transmitters. A mean number of 13 locations/individual/month was recorded for a total of 7902 fixes. Adult males were divided in 19 residents (territorial males, with overlapping or adjacent warm and cold month ranges) and four migrants (with non-overlapping warm and cold month ranges, as well as attending higher altitude areas in the warm months). Home range and core area (kernel 95 and 50%, respectively) sizes of each individual were significantly greater in the warm (June-November) than in the cold (December-May) periods. During the warm period, home range and core area sizes significantly differed between resident (median home range: 49 ha; Q 1 -Q 3 : 31-110 ha) and migrant males (median home range: 749 ha; Q 1 -Q 3 : 539-850 ha), as well as between females (median home range: 711 ha; Q 1 -Q 3 : 388-1842 ha) and resident males. No significant difference was observed in the cold period. Home range size was not correlated to the presence of snow cover (≥ 70%). Throughout the year, nearly all chamois used south-to southeast-facing slopes. Resident males strongly preferred pastures and meadows, but four of them used alder shrublands on the north-east slope more than expected, in the warm months. Females kept nearly always at altitudes greater than those used by resident males and inhabited higher-quality areas.