Detectability of the European red squirrel (Sciurus vulgaris) in a Mediterranean area.

Detectability of the European red squirrel (Sciurus vulgaris) has rarely been investigated in Mediterranean forests. In this study we used occupancy models to investigate detectability in relation to habitat types by squirrels, in a mosaic of different forests types, in a hilly area of Central Italy. The distribution of the target species was investigated by using hair tubes. Overall, there was a prevalence of hair tubes used by squirrels in mixed conifers and deciduous forests and in young deciduous forests than in coniferous forests. Our preliminary study shows that habitat type may influence the probability of red squirrel detection rather than the species presence; therefore, future studies should take this differential detectability into account either by applying occupancy models or by adjusting sampling effort accordingly.