A multidisciplinary approach to estimating wolf population size for long-term conservation

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Non-invasive integrated sampling design to monitor the wolf population in Piemonte, Italian Alps

The natural return of the wolf (Canis lupus) in the western Alps of Italy and France at the beginning of the 1990's, after 70 years of absence, is an important ecological and social event. The Regione Piemonte, in the course of the Progetto Lupo Piemonte, intensively monitored the wolf population over the Piemonte territory from 1999 to 2010. We estimated four main population parameters over time (wolf population size, number of packs, distribution, and effective population size) in order to follow the natural recolonization process over the Alps. An integrated sampling approach was designed to collect data to estimate simultaneously and cost-effectively these four parameters. This combined monitoring program allowed the development of specific management strategies for the mitigation of wolf-human conflicts, given the protected status of the alpine wolf population. This transboundary wolf population, which dispersed over the Alps of Italy, France, Switzerland, and now is reaching the Eastern Alps, has been considered a unique and distinct entity by the European Commission after the "Guidelines for Population Level Management Plans for large Carnivores". Therefore, it should be monitored and managed as such over the boundaries, and this cost-effective sampling approach should be considered in this framework

Temporal changes of howling in south European wolf packs

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

Predation by wolves (<i>Canis lupus</i>) on roe deer (<i>Capreolus capreolus</i>) in north-eastern Apennine, Italy

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 &lt;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

Wolf Dispersal Patterns in the Italian Alps and Implications for Wildlife Diseases Spreading

Wildlife dispersal directly influences population expansion patterns, and may have indirect effects on the spread of wildlife diseases. Despite its importance to conservation, little is known about dispersal for several species. Dispersal processes in expanding wolf (Canis lupus) populations in Europe is not well documented. Documenting the natural dispersal pattern of the expanding wolf population in the Alps might help understanding the overall population dynamics and identifying diseases that might be connected with the process. We documented 55 natural dispersal events of the expanding Italian wolf alpine population over a 20-year period through the use of non-invasive genetic sampling. We examined a 16-locus microsatellite DNA dataset of 2857 wolf samples mainly collected in the Western Alps. From this, we identified 915 individuals, recaptured 387 (42.3%) of individuals, documenting 55 dispersal events. On average, the minimum straight dispersal distance was 65.8 km (±67.7 km), from 7.7 km to 517.2 km. We discussed the potential implications for maintaining genetic diversity of the population and for wildlife diseases spreading

Predation by wolves (<i>Canis lupus</i>) on wild and domestic ungulates of the western Alps, Italy

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

Selection of rendezvous sites and reuse of pup raising areas among wolves <i>Canis lupus</i> of north-eastern Apennines, Italy

A coarse scale analysis was carried out of factors affecting rendezvous site selection and fidelity to pup raising areas in wolf Canis lupus Linnaeus, 1758 packs inhabiting the north eastern Apennines, Italy. From 1993 to 2004, 44 rendezvous sites were identified, and compared with random sites for variables related to topography, habitat, and human presence. Rendezvous sites were significantly more frequent inside protected areas and at a significantly greater distance from paved roads and villages than random sites. Moreover, they were located on a significantly steeper slope and at a higher absolute elevation than random sites, whereas we did not observe selection of a particular aspect. Deciduous forests were selected, whereas open areas were not used. Canopy cover above 70% was positively selected. Distance from protected areas border and paved roads, and presence of deciduous forest proved the main factors affecting rendezvous site distribution. In four cases we observed the reuse of the same rendezvous sites for two consecutive years. Some packs tended to locate their rendezvous sites in small portions of their territory, thus implying that some areas are more suitable for pup raising

Transboundary Monitoring of the Wolf Alpine Population over 21 Years and Seven Countries

Wolves have large spatial requirements and their expansion in Europe is occurring over national boundaries, hence the need to develop monitoring programs at the population level. Wolves in the Alps are defined as a functional population and management unit. The range of this wolf Alpine population now covers seven countries: Italy, France, Austria, Switzerland, Slovenia, Liechtenstein and Germany, making the development of a joint and coordinated monitoring program particularly challenging. In the framework of the Wolf Alpine Group (WAG), researchers developed uniform criteria for the assessment and interpretation of field data collected in the frame of different national monitoring programs. This standardization allowed for data comparability across borders and the joint evaluation of distribution and consistency at the population level. We documented the increase in the number of wolf reproductive units (packs and pairs) over 21 years, from 1 in 1993–1994 up to 243 units in 2020–2021, and examined the pattern of expansion over the Alps. This long-term and large-scale approach is a successful example of transboundary monitoring of a large carnivore population that, despite administrative fragmentation, provides robust indexes of population size and distribution that are of relevance for wolf conservation and management at the transnational Alpine scale