A comparison of scat-analysis methods to assess the diet of the wolf.

Six scat-analysis method were compared and tested for differential assessment of a wolf Canis lupus diet in the Northern Apennine Mountains, Italy. A sample of 217 wolf seats was analysed using standardised laboratory techniques, and the recovered undigested remains were quantified according to the following diet measurements; frefluency of occurrence, dry weight (estimated and measured), relative volume, and biomass ingested (two methods). With the exception of one of the biomass methods, there was no significant disagreement between the procedures examined. However, some discrepancies between rankings from different methods indicated the sources of bias that should be accounted for to avoid misleading conclusions. Frequency data can be corrected to reduce some of the associated forms of bias, whereas rankings by weight and volume appear affected by the structure of undigested remains. Although to different extents, all the methods which rank food items according to direct measures of the undigested remains, i.e. by frequency, weight, and volume, suffer from the surface to volume ratio bias of varying prey sizes. Linear-regression biomass models for the surface/volume bias, but there are some drawbacks when applying them, and they are limited to mammalian prey. Applicability of the biomass models should be evaluated on the basis of tiler composition and prey sizes, and results carefully interpreted in concert with oilier field- collected information. Interpretation of seat-analysis data in order to assess the diet of wolves, as well as of other carnivores, would be greatly enhanced by comparing results obtained with two or more methods

Distance Sampling and Thermal Immaging to assess a roe deer population in Northern Appennines: the pros and cons of a fashionable technique.

The recent development of Oistance Sampling techniques (OS) has provided a promising device to yield good population estimates with samples of small size (40-80 independent detections) with reasonable survey costs. On this subject, during the past Roe deer Meeting (Portugal) were presented interesting results suggesting that OS coupled with thermal imaging (IR) could be a suitable and costeffective monitoring methodology. We present the results of a 3-year project devoted to compare density estimates from OS & IR with more conventional Mark Recapture (MR) estimates of an Appennines roe deer population. We worked in an open hunting estate, where a long-term study on roe deer ecology includes radio-monitoring and densities assessment since 1995. We tested the possibility to survey roe deer using a portable thermo-camera, equipped with a laser rangefinder and an electronic compass, which allows the operator to record ani mais presence (group size and number of groups) also in completely dark night and to measure their distance and angle with respect to the observer. We walked 35 transects (total effort 20.5 km) in 3 nights, from 7:00 PM to 5:00 AM, to survey an area of 523 ha. We made 2 survey replicates each year (late winter/early spring) to compare the results with estimates of early spring survey calculated by MR methods. Night survey is thought to mitigate the problem of g(O) < 1 (which affect daylight ones when animals f1y away reacting to the presence of an observer) because the use of an IR camera is supposed to allow the detection of deer before being discovered. However, IR & OS survey design could be biased because observers are forced to use paths and so transect positioning may not be random with respect to ani mais distribution. We present an a posteriori evaluation of the survey design and we compare the 2 survey methods in order to assess the presence of biases in IR & OS

Inter-pack, seasonal and annual variation in prey consumed by wolves in Pollino National Park, southern Italy

Although understanding of food habits of wolves in human-modified landscapes is critical to inform conservation and conflict management, no such studies have ever been conducted in the southern Apennines, Italy, where wolves long coexisted with humans. By means of scat analysis (n = 1743) and log-linear modelling, we investigated diet composition in five wolf packs in the relatively simple prey system of the Pollino National Park (PNP), southern Italy (1999−2003). Overall, although wild boar was the most frequently consumed prey (mean frequency ± SD, 63.1 ± 23%), both wild boar and cattle predominated the diet in terms of biomass (45.3 ± 24 and 48.1 ± 21%, respectively). We revealed, however, a zonal (i.e. area, pack) followed by annual and seasonal effects on the wolf diet. Cattle consumption by wolf packs in the northern portion of PNP (Pollino subrange) was highest, especially during summer when cattle predominated the diet in terms of biomass (68.3 ± 20%). Instead, wild boar consumption was highest in the Orsomarso packs (biomass, 62.1 ± 13%), with increasing trends throughout the study period but no relevant seasonal variation. Wild boar piglets and cattle calves were the most frequently consumed age classes, revealing their availability year-round and higher profitability compared to other prey. Cattle consumption by wolves reflected prevailing husbandry techniques (free-ranging herds with unattended births) and determined a permanent state of conflict, often spurring retaliatory killing of wolves. Compatible cattle husbandry practices, along with the restoration of multi-prey communities, are needed to reduce wolf-livestock conflicts and possibly enhance the ecological role of wolves in human-altered ecosystems