Home range dynamics of mountain hares (Lepus timidus) in the Swiss Alps.

Little is known on the ecology and behaviour of the alpine mountain hare (Lepus timidus). Between 1996 and 1997, we analysed by radiotracking the pattern of space use of 8 mountain hares from the Swiss Alps. We estimated home range size using both the kernel density estimator and the minimum convex polygon. We found smaller ranges (38 ha) compared to those reported for the species in boreal or arctic habitats, but similar to ranges in Scotland. Hares did not use a centre of major activity (core area) and showed high home range overlap, confirming their non-territorial behaviour. Smaller ranges were used during winter compared to the other seasons, whilst no difference in size was found between sexes

Open Source evaluation of kilometric indexes of abundance.

Kilometric Abundance Index (KAI) is a common measure used in wildlife studies because it allows a straightforward comparison of species abundance in different sites or at different times. KAI expresses the ratio of the total number of individuals (or of signs of presence) observed along a transect by the total transect length covered at each site. v.transect.kia is a new tool for GRASS GIS, developed for automating the evaluation of KAI, reducing the risk of manual errors especially when handling large datasets. It can also split the transects according to one environmental variable (typically habitat type) and evaluate true 3D transect length. It calculates KAI using a point map of sightings and saves the results in the attribute table, the output can be displayed in any GIS or used for further statistical analysis. The tool has been tested on field data from Northern Italy for mountain hare (Lepus timidus), allowing a first wide-area estimate

Does Nathusius' pipistrelle Pipistrellus nathusii (Keyserling & Blasius, 1839) breed in northern Italy?

This paper reports the capture of seven adult Pipistrellus nathusii including a lactating female mist-netted in July 1997 in Varese province (northern Italy). This record represents the first identification of a breeding female Nathusius' pipistrelle in the south part of the Alps. Other data on the reproduction of this species in Europe are discussed in order to reconsider its distribution and breeding sites

Radio-tracking squirrels: performance of home range density and linkage estimators with small range and sample size

Studies that use radio-tracking to reveal social structure and habitat use in populations of small and medium-sized mammals face a trade-off between number of location data (n) and monitoring of many individuals, to maximize efficiency.We simulated these conditions using location data from 30 radio-collared red squirrels, subsampled at different percentages of total number of locations and tested the performance of four home range estimators. Two linkage estimators, the minimum convex polygon (MCP), and the incremental clusteranalysis polygon (ICP) and two probability density estimators, the fixed kernel density estimation with reference smoothing factor (KDE with href), and with least squares crossvalidation to calculate smoothing factor (KDE LSCV with hlscv). KDE produced the largest home range estimates, MCP and KDE LSCV intermediate estimates, and ICP the smallest ones. Differences between estimators were larger at smaller n, but consistent throughout the entire range of locations (16\u201374) in our data set. Although KDE is widely used and LSCV is widely recommended to calculate bandwidth, our results confirmed that the value of h has a considerable influence on the home range estimate and varied more strongly when sample size (n) decreased. Our models showed that overestimation with KDE could be avoided by applying the average ratio of hlscv/href (in our case 0.75) as a multiplier of href and use this recalculated bandwidth to produce more reliable home range and core area estimates (KDEadj). MCP and KDE had lower variability than KDE LSCV and ICP. Stability improved with sample size and tended towards an asymptote at more than 60 locations for MCP and KDE. We conclude that high variation in ICP and KDE LSCV at small n limits their applicability to few situations (n > 70, landscapes with distinct habitat patches where ranges consists of several, separated cores). We recommend use of both MCP and KDEadj for home range size and KDEadj for core area size and propose to estimate a \u2018best core area\u2019 based on 85% MCP when a home range is mononuclear and 85% ICP when it is multinuclear

Behavioral Responses of Wintering Great Crested Grebes to Dissuasion Experiments: Implications for Management

Great Crested Grebes (Podiceps cristatus) wintering on prealpine lakes of north Italy are considered to cause economic damage to fish, reducing the stock of native Bleak (Alburnus alburnus). We experimentally investigated the effectiveness of three deterring actions (gas-cannon, crackers and shooting) in four study sites at Lake Como, by comparing the time-budget and space-use of wintering grebes in absence and presence of disturbance. All dissuasion methods affected grebe behavior and position on the lake, but some resulted more effective than others. The gas-cannon detonations had little effect, but, crackers and shooting caused significant changes in grebe behavior. Grebes spent less time feeding, resting and preening, but more time moving/swimming during dissuasion than in the control situation. Moreover, birds also moved away from the areas with bleak shoals, resulting in a significant decrease in grebe numbers with either dissuasion methods. Although dissuasion reduced feeding of grebes in areas with shoals of Bleak (Alburnus alburnus), and probably reduced grebe predation on immature fish at localized areas, it involves intensive effort, in terms of man-day