Ecological correlates of Golden eagle (Aquila chrysaetos) breeding occurrence in Sardinia (Italy).

Capsule Golden Eagles Aquila chrysaetos in Sardinia are clustered across the main mountain ranges of the island, with a preference for undisturbed and homogeneous inland habitats. Aims To analyse habitat preferences of the Golden Eagle in Sardinia, Italy, at the landscape and home range spatial scales. Methods Landscape scale habitat preferences were analysed using the 10 × 10 km Universal Transverse Mercator grid and the home range scale was based on the spatial distribution of breeding territories. Generalized linear models were fitted with three different sets of environmental predictors (topographic, bioclimatic and land use variables) to analyse the spatial distribution of Golden Eagles with a case-control design. Results Eagles showed a preference for rugged and elevated areas, characterized by a certain degree of humidity and surrounded by areas of forest. The distribution of Golden Eagles on this Mediterranean island was negatively affected by the occurrence of arable farmland and coastal areas, as well as by the effects of habitat fragmentation. Conclusions The results of this study could contribute to future management strategies and conservation projects aimed to protect this species, and may be used to identify the most suitable conservation areas for this and other competing species, such as the Bonelli's Eagle Aquila fasciata, which is currently the subject of a reintroduction project in Sardinia

Ecological correlates of roe deer fawn survival in a sub-Mediterranean population

We investigated the effect of body mass, spring and summer total rainfall, birth period, and local population density on the survival of 130 roe deer (Capreolus capreolus (L., 1758)) fawns captured over seven fawning seasons (1997-2003) and radio-monitored daily. We modelled survival using the program MARK, incorporating biological questions into different models, following a priori hypotheses. The best model was selected using Akaike's information criterion. The population was surveyed by counts and estimates were obtained using mark-resight methods. Weekly survival of roe deer fawns exhibits a pseudo-threshold time trend. Probability of survival is low (0.33 +/- 0.0046) in summer, increases (0.79 +/- 0.0021) in fall, and approaches the highest value typical of adult survival (0.90 +/- 0.00091 and 0.96 +/- 0.00021 by the end of March and May, respectively) during early spring following birth. The final model predicts that survival of roe deer fawns is positively affected by total precipitation in spring and body mass under a pseudo-threshold time variation pattern. In contrast with other studies, we did not detect any effect of population density on survival of fawns. This study contributes to the scarce knowledge about the performance of roe deer populations in Mediterranean ecosystems, providing evidence that climate variables and individual characteristics shape the vital rates of roe deer populations

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

Episodi di mortalità determinati da E. coli nel capriolo nell'Appennino settentrionale

0:74 Escherichia coli epidemic in a Roe deer metapopulation of the Northern Apennines, Italy. An epidemic of enteropathogenic (EPEC) E. coli in a in a free living metapopulation of Roe deer Capreolus capreolus of the Northern Apennines (Italy) is described. 40 out of the 132 censued animals were radiocollared. In the radiocollared animals the infection resulted in a morbility of 12.5% (SD 5.2%), with a lethality of 80% (SD 18%) and the whole mortality reached 10%.(SD 4.7%). The E. coli responsible of the infection was classified as 0:74. The pathological lesions and some clinical features of the infection are described.[...

Episodi di mortalit\ue0 determinati da E. coli nel Capriolo nell\u2019Appennino Settentrionale

- 0:74 Escherichia coli epidemic in a Roe deer metapopulation of the Northern Apennines, Italy. An epidemic of enteropathogenic (EPEC) E. coli in a in a free living metapopulation of Roe deer Capreolus capreolus of the Northern Apennines (Italy) is described. 40 out of the 132 censued animals were radiocollared. In the radiocollared animals the infection resulted in a morbility of 12.5% (SD 5.2%), with a lethality of 80% (SD 18%) and the whole mortality reached 10%.(SD 4.7%). The E. coli responsible of the infection was classified as 0:74. The pathological lesions and some clinical features of the infection are described

The need for a flyway approach in defining the onset of prenuptial migration of huntable bird species across Europe

The identification of the onset of prenuptial migration is fundamental in defining the closing date of the hunting season in compliance with the EU Birds Directive. Here, we describe the process and country-by-country approach currently followed by the European Commission to define the onset of prenuptial migration for each huntable bird species and Member State, highlighting the resulting discrepancies and inconsistencies in the starting dates of prenuptial migration between neighbouring countries. To overcome these issues, we propose the adoption of a flyway approach with a shared, analytically and biologically sound method for defining the onset of migration