EN
We investigated the foraging behaviour of the Mediterranean horseshoe bat (Rhinolophus euryale) in an Atlantic mosaic-like landscape consisting predominantly of meadows and broadleaved tree structures, and containing the largest known breeding colony in northern Iberian Peninsula. We radio-tracked a total of 46 individuals during pre-breeding, lactation and post-lactation periods. Bats were divided into different classes based on season, sex, reproductive condition or age. Significant differences between classes were apparent in the distances travelled to foraging areas. During pre-breeding foraging occurred on average within 1.3 km, and at most 4.2 km from the roost. Contrary to our predictions, lactating females extended mean foraging distances to 4.3 km, and covered the widest range with a maximum individual distance from the roost of 9.2 km. Males in the same period foraged closer (mean 1.9 km), but with lower fidelity to the main roost. The foraging distances of adult bats during post-lactation did not differ from that of lactating females (mean 4.6 km). Newly volant juveniles flew on average 2.6 km, though showed a varied behaviour. No seasonal effect was found on the size of individual foraging home ranges, as great variation was recorded within all groups. We conclude that the increase in foraging distances is the consequence of higher density as colony size increased by 55% from pre-breeding into the lactation period on. Our results show another aspect of the scale of foraging movements of R. euryale and highlight the need to take these into account when formulating conservation policy, especially during such crucial periods as lactation and juvenile dispersal.