Winter habitat selection of invasive Eastern Cottontail (Sylvilagus floridanus) in Tuscany (Central Italy)

Eastern Cottontail (Sylvilagus floridanus) is an invasive species in Italy and it occurs in many Central and Northern regions. The species is increasing its distribution and some works highlight its potential role as a vector of infective diseases and parasites that can be dangerous for native European Brown Hare (Lepus europaeus). Despite this no studies have assessed the habitat use of Eastern Cottontail into its area of introduction in Tuscany. From December 2013 to February 2015 habitat use of Easter Cottontail was assessed during nine spotlight surveys from a vehicle that were performed in 4 protected areas and in a hunting estate in the provinces of Pistoia and Firenze (Italy). Surveys were performed by gamekeepers and wildlife technicians and started two hours after dark. The off-road vehicle moved approx. at 5 mph on available roads in a way to ensure a representative sampling of different habitats. At least two replicates were performed in each estate but two areas were sampled only once, at the beginning of March 2014, because of inaccessible roads and weather conditions. Spotlight area, habitat categories and individuals were recorded and mapped with QuantumGIS. The distance of each individual from the transect was measured with a laser rangefinder and this allowed us to improve the accuracy of spotlight area. Habitat categories were: tree plantations, maize fields, ploughed fields, wheat crops, woodlands, fallows, riparian vegetation, houses and gardens, olive trees, meadows, vineyards and hedgerows. Habitat selection was measured on mapped surfaces within the spotlight area. Selection was assessed with a selection index (w) and significance was tested with chi-square goodness of fit test and Bonferroni’s simultaneous confidence interval. A total of 278 individuals were recorded. The chi-square test revealed significant differences between the distribution of observed individuals and habitat proportions (chisq=20.41, df=11, p < 0.05). Tree plantations, fallows, maize stubbles, woodlands and riparian vegetation were positively selected, while wheat crops, hedgerows, meadows and ploughed fields seemed to be avoided by Eastern Cottontail. The graphical examination of Bonferroni’s confidence interval revealed that a significant selection only occurred for fallows (w=1.48), wheat (w=0.23) and meadows (w=0.6). Our results partially agree with others obtained by previous works in Northern Italy. Eastern Cottontails seem to avoid open areas, such as meadows. Our sampling time encompassed the emergence and tillering phase of wheat therefore this crop provided little or no cover and was avoided. Habitat that can provide a higher degree of permanent cover, notably fallows, are instead positively selected. However some typologies that should have given shelter were avoided, notably hedgerows. These results could have been influenced by a low detectability of Eastern Cottontail in some field conditions, due to vegetation growth. Therefore other techniques, as radiotracking of tagged individuals or random spotlight transects, should integrate traditional spotlight surveys, providing further insights about the habitat selection made by the specie