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|Autori: ||Bisi, Francesco|
|Tutor interno: ||MARTINOLI, ADRIANO|
|Titolo: ||Conservation of Biodiversity in Alps: mountain hare (Lepus timidus) as model system.|
|Abstract: ||Knowledge about mountain hare (Lepus timidus) is still scarce, especially in alpine ecosystem. We collected information about mountain hare behaviour and distribution to asses if this species can be a useful indicator of environmental changes across the Alps.
First, we tested two di_erent live capture methods for mountain hare in Scotland and we verified if sex or age composition and body condition of hares di_ered between methods.
Individuals in poor condition were more frequently taken with traps, a tendency which may reflect increased risk taking of individuals in poorer body condition and less aversion to entering traps to bene_t from eating bait. We then used data of body mass of recaptured hares in two study areas in Italy. Here we did not _nd di_erence in body mass between _rst capture and recaptured hares, supporting the hypothesis that di_erences in capture methods, at least partly, depend on the habitat type where they have been applied.
The main part of the _eldwork aimed to investigate space and habitat use of mountain hare in relation to habitat structure and composition. We analysed the space-use patterns of two mountain hare populations from the Central Alps using radiotracking.
We monitored 34 hares, estimating home range size, overlap and site _delity, and compared our data with space use in Scottish and North-European populations. Home ranges of mountain hares did not di_er between two study sites with di_erent habitat types.
Subadult animals used larger ranges than adults and both age groups reduced home range size in autumn, a period that might be critical for hares due to changes in diet and/or high energy expenditure during the previous breeding season. Younger hares probably made exploratory movements to gather information about surrounding habitats. Home ranges in alpine 'edge' populations were smaller than in Scandinavian populations, but within the range of populations in di_erent habitat types in Scotland. Seasonal home ranges overlapped considerably, but di_ered among the sexes: intersexual overlap in males (thus with females) was larger than spatial overlap among other sexes. Seasonal shifts of home ranges were small and site _delity remained constant over the di_erent seasons, suggesting that resource distribution remained constant throughout the year and that the knowledge of an intensively frequented area is an important element of habitat quality.
From data collected with radiotracking we also analysed habitat selection of mountain hares. Hares selected closed habitat and avoided open habitat with poor productivity.
We found the same patterns at di_erent temporal scales: day and night ranges, seasonal ranges and annual ranges. The most preferred habitat type was dwarf mountain-pine, important for hares during winter, being the only available food resource, and still fundamental during the rest of year because it o_ers resting places. Dwarf mountain-pine present the highest High Heating Value (HHV) among the available food resources. For conservation reasons, we also analysed mountain hare interaction with cattle on alpine pastures. Presence of cattle on pastures did not result in a shift in habitat selection by hares.
Based on culled animals, we also analysed reproductive parameters of mountain and brown hare (Lepus europaes): litter size, number of litters per year and number of leverets per litter. Reproductive parameters of mountain hare were similar to those reported for other subspecies across its distribution range. In contrast, those registered in this study for brown hare suggested adaptation of brown hares to colder environments.
Finally, we explored population-genetic parameters, using mtDNA and nuclear microsatellites analysis. Two animals trapped in one of our study areas were hybrids between mountain and brown hare, supporting the fact that hybridisation processes are present also on the Alps as already reported for other populations living in the Northern parts of mountain hare distribution range.
Data collected support the hypothesis that alpine mountain hare populations undergo pressure related to environmental changes. This tendency becomes evident only taking into account di_erent aspects of its ecology, genetics and distribution.|
|MIUR : ||BIO/03 BOTANICA AMBIENTALE E APPLICATA|
|Corso di dottorato: ||Analisi, Protezione e Gestione delle Biodiversità|
|Ciclo di dottorato: ||22|
|Università di conseguimento titolo: ||Università degli Studi dell'Insubria|
|Citazione: ||Bisi, F.Conservation of Biodiversity in Alps: mountain hare (Lepus timidus) as model system. (Doctoral Thesis, Università degli Studi dell'Insubria, 2010).|
|PhD thesis bisi completa.pdf||testo completo tesi||11,33 MB||Adobe PDF||non consultabile
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