A management plan for the European pond turtle (Emys orbicularis) populations of the Louro river basin (Northwest Spain)

Emys orbicularis is the most endangered reptile in Galicia (Northwest Spain). Only two large population groups are known in the region, and the species is also rare in the north of Portugal, suggesting that Galician populations are currently isolated. Here we present an analysis of the Louro river populations (Pontevedra province), which consist of approximately 100 turtles. Fieldwork from 1996 to 2002 allowed us to estimate sex ratio, survivorship and recapture rates, reproduction, mobility between ponds, and size distribution. We were unable to find nesting sites and therefore have very limited information about clutch size. Based on these demographic parameters and literature data, we performed a population viability analysis for a local population with Vortex software. It helped to identify six major conservation problems in the study area: (i) introduction of exotic species (predators: black-bass; competitors: Trachemys scripta); (ii) capture of turtles for pet trade; (iii) direct disturbance; (iv) increased extinction risk due to small population size; (v) habitat destruction; (vi) water and soil pollution. A management plan is proposed to minimize the impact of these factors.