Post‐release behaviour, home range establishment and settlement success of reintroduced red squirrels

The behaviour of eight radiotagged red squirrels (Sciurus vulgaris Linnaeus, 1758) reintroduced at Parco Groane, northern Italy, was monitored for two months following their release. Both male and female squirrels moved over considerable distances the first two weeks after introduction, exploring the new habitat. Two types of exploring behaviour were observed: (i) gradually expanding the home range, moving only short distances each day; and (ii) making regular excursions of more than 1 km followed by short periods of activity in a small area. The latter behaviour resulted in very large home ranges during the exploring phase. After the initial exploring, home range size decreased and one male and two female squirrels changed their space use by increasing the number of activity centres (core‐areas) within their home range. Post‐settlement home ranges were spaced out over the available habitat and all squirrels used almost completely exclusive core‐areas. Only four red squirrels (two males and two females) survived long enough to be the potential founders of the new population that established itself at Parco Groane. We discuss methods to decrease post‐release mortality in red squirrels and consider genetic and demographic consequences of squirrel reintroductions.