Conservation measures for a population of Hermann's tortoise Testudo hermanni in southern France bisected by a major highway

Abstract

Between May 1989 and October 1990 a highway was constructed through the core area of one of the largest French populations of Testudo hermanni, a species seriously threatened by habitat loss and habitat fragmentation. Two general strategies were used to alleviate negative impacts of the highway on the tortoise population: first, 300 tortoises, that were directly affected by the highway construction, were temporarily maintained in outdoor enclosures and relocated after construction was completed; secondly, attempts were made to reduce traffic impacts on the tortoise population, including the use of fences to keep tortoises off the road and the construction of culverts and a tunnel under the road to provide for movements of animals between the separated habitat areas. The short-term outcome of this conservation exercise was a success: the annual survival rate of 78% observed in reintroduced tortoises was comparable to published results of translocation of other tortoise species into unfamiliar habitat; traffic mortality of tortoises in the 4 years following highway construction was low and mark-recapture results indicate a stable adult population and the use of the culverts and the tunnel by tortoises to cross the road.