Predation by wolves Canis lupus on roe deer Capreolus capreolus was studied by scat analysis in five areas of the Province of Arezzo, north-eastern Tuscany, Italy. In the intensive study area (ISA) roe deer represented 19.1% of mean per cent volume (MPV) while in the other areas its use ranged between 10.9% and 53.4% of MPV. A low degree of variation was found in both annual and seasonal use of roe deer, although seasonal differences were more marked in those areas where roe deer use was lower. In ISA, roe deer was negatively selected among species: the Ivlev's electivity index ranged between − 0.41 and − 0.89. Analysing intra-specific selection, in ISA < 1-year-old individuals were preferred by wolves, mainly during the fawns' first months of life. This trend was confirmed in the other areas, where fawns represented more than 50% of the relative number of roe deer prey. In ISA, the use of roe deer (as MPV) was not correlated with its density or with that of the main prey, wild boar, and in almost all the other areas no relation between use and density of roe deer was founded. However, in the one area where both roe deer density and use were the highest, these two variables seemed to exhibit a comparable trend. The use of roe deer was negatively correlated with the percentage of forest cover among all the study areas.

No abstract

Studies on predation by the wolf (Canis lupus) have often reported contradictory results about the role of prey density and vulnerability on wolf prey use. We investigated dietary response and prey selection by wolves in a high-density and multi-species ungulate community, analysing scats collected over a period of 11 years in the Casentinesi Forests, Italy. The second most abundant species, wild boar (Sus scrofa), was found to be the main wolf prey, and we did not observe any dietary response of wolves to variations in the density of either primary or secondary prey species. Selection patterns were uniform throughout the study period. Wolves strongly selected for wild boar piglets, while roe deer (Capreolus capreolus) fawns and adults, red deer (Cervus elaphus) adults and fallow deer (Dama dama) adults were avoided. Wolf preference for wild boar was inversely density dependent. Within each species, juveniles were preferred to adults. Medium-sized, young individuals of both wild boar and roe deer were optimal prey, although with different selection patterns related to the different anti-predator strategies adopted by each prey species. The results of this study suggest that in productive ecosystems with high density and high renewal rates of prey, selection patterns by wolves are determined by prey vulnerability, which is connected to prey age and body size. The different patterns of wild boar versus cervids use by wolf across Europe seems to be related to their relative abundances, while the strong selection of wild boar in Italian Apennines with respect to the more frequent avoidance in central-eastern Europe is better explained by higher piglet productivity and smaller body size of adults boar in Mediterranean temperate forests.

Howling was elicited in three wolf packs, monitored on the Italian Apennines, between 1996 and 2000. To test their attitude to reply to extraneous individuals, wolves were stimulated by playback of tape-recorded howls emitted from prominent sites.Responses were recorded and processed by sonographic analysis, discriminating between choral and single replies, and evaluating the presence/absence of cubs. The overall reply rate was 12.6%. Responsiveness was high during late summer-early fall, a period coinciding with abandonment of the den and translocation of the litter to rendezvous sites. At this time, chorus howling represented the majority of total replies, and the quickness of responses suggests a higher bent to vocalize. Throughout the year, late evening and dawn were the parts of the day at which wolves showed the maximum tendency to respond.

The ability to estimate quantity, which is crucially important in several aspects of animal behaviour (e.g. foraging), has been extensively investigated in most taxa, with the exception of reptiles. The few studies available, in lizards, report lack of spontaneous discrimination of quantity, which may suggest that reptiles could represent an exception in numerical abilities among vertebrates. We investigated the spontaneous ability of Hermann's tortoises ( Testudo hermanni ) to select the larger quantity of food items. Tortoises were able to choose the larger food item when exposed to two options differing in size, but equal in numerousness (0.25, 0.50, 0.67 and 0.75 ratio) and when presented with two groups differing in numerousness, but equal in size (1 versus 4, 2 versus 4, 2 versus 3 and 3 versus 4 items). The tortoises succeeded in both size and numerousness discrimination, and their performance appeared to depend on the ratio of items to be discriminated (thus following Weber's Law). These findings in chelonians provide evidence of an ancient system for the extrapolation of numerical magnitudes from given sets of elements, shared among vertebrates.

No abstract

Wolf-ungulate interactions were studied in a mountainous region of the western Alps (Italy) from December 1999 to November 2002. Analysis of 848 scats of wolves Canis lupus showed that their most important prey was wild ungulates (87.2%). Cervids were the preferred prey (74.2%) and constituted predominant food items both in winter (84.2%) and summer (54.3%). Wolves preyed most intensively upon young ungulates. Presence of domestic ungulates on high-altitude pastures during summer (May-October) influenced wolf diet (summer 19.0%, winter 0.3%), but, despite the major density of domestic livestock, wolves still preferred wild ungulates. A strong trophic relationship between wolves and red deer Cervus elaphus emerged from the present study. During three winters, 177 ungulate carcasses were recorded. Excluding hunting, the most important cause of death in red deer was predation by wolves (51.5%), followed by disease and starvation (36.4%) and traffic accidents (12.1%). The majority of red deer killed were hinds (58.8%) and calves (29.4%); stag kills represented only 11.8%. For roe deer Capreolus capreolus, starvation and diseases were the lowest factor (11.5%), slightly higher than wolf predation (10.8%), while traffic accidents were the main cause of mortality (77.7%). Chamois Rupicapra rupicapra seemed to be less important than red deer and roe deer in the diet of wolves. The high susceptibility of red deer to wolf predation could be a result of the strong overlap of habitat and altitude use with the wolf, and to their more conspicuous herding.

Depredation on livestock and wolf pack Canis lupus distribution was investigated in the province of Arezzo, Tuscany, from 1998 to 2001. Although livestock was uniformly distributed, damage level and distribution were focused in the mountainous area inhabited by wolf packs hence there were huge differences between areas with and without wolves. In the whole province a few farms were persistently affected by predation (6%), and they reported 38% of the total attacks and 37% of the total losses. Surplus killing phenomena involved only sheep and goat farms, affecting 18% of the total. Thirty-five attacks (14% of the total attacks) reported 536 kills (44% of the total livestock killed in the whole province of Arezzo). During the period 1998-2001, compensation costs in the province averaged 86 863 Euros (range: 68 805-99 318 Euros). In the same period, no farmer requested prevention funding from the Tuscan region. During the study period wolf population was stable: wolf packs were distributed on 47% of the whole province (1504 km 2 ), with a density estimated at 2.9 AE 0.7 wolves 100 km À2 .