Ecological aspects and effects of forestry management on a population of Hermann’s tortoise (<em>Testudo hermanni hermanni</em>) in Catalonia (Spain)

Abstract

The aim of this research was to evaluate the effects of forestry works on Testudo hermanni hermanni, and to establish ecological parameters useful for habitat management. This study took place in the northeast of Spain, in the Albera Mountains, where one of the last natural populations of Hermann’s tortoises lives. Twenty-one tortoises were weekly monitored using radiotracking during six months, between July 2009 and January 2010. Between October 2009 and January 2010, forestry works took place at the study site. The impact of the forestry works and the associated damages were estimated using two approaches: the displacements of the monitored tortoises and the use of plaster models resembling tortoises, which were placed in similar locations and conditions to live tortoises. Radiotracking results showed that 30% of the tortoises were found on open areas (pastures and sparse cork oak forest), whereas 70% corresponded to dense forests and heath scrubland locations. The analysis of the effect of forestry works showed that tortoises were affected by the works in 45% of the cases, even during hibernation period. The simulation results of the impact of the forestry works based on plaster models showed that 4% of the models were seriously damaged when using manual works (brush cutters and clearing saws), whereas mechanized works (chain tractor) were responsible for an estimation of 22% mortality and 6% serious damages.