Estimating the population density of Iberan wild goat Capra pyrenaica and mouflon Ovis aries in a Mediterranean forest environment

Abstract

Aim of study: To manage and conserve wild populations effectively, a good understating of population density is critical. During 2010, the density of Iberian wild goat Capra pyrenaica and mouflon Ovis aries were estimated. Area of study: The area is situated in Muela de Cortes Game Reservation (Spain), a Mediterranean forest plateau, after a mange Sarcoptes scabiei outbreak that affected both species. Material and methods: To measure the abundance, sex ratio and productivity of the Iberian wild goat and mouflon. Field work was conducted during spring (after parturition) and autumn (during rut) by walking along itineraries, using a Distance Sampling approach. Main results: Based on DS, the best relative fit of model and adjustment term for Iberian wild goat was hazard-rate cosine, based on the lowest AIC score. The average density for Iberian wild goat was 4 km-2 (95% CI: 2,3-6,9) (after parturition) and 3,6 km-2 (95% CI: 2-6.6) (during rut). Average estimation was 1,422 goats (95% CI: 813-2,487) after parturition and 1,308 during rut (95% CI: 725- 2,362). Mouflon best relative fit of model and adjustment term was uniform cosine after parturition, based on the lowest AIC score. The best relative fit of model and adjustment term for mouflon was hazard-rate cosine, based on the lowest AIC score. The average density was 6.8 mouflon km-2 (95% CI: 4.7-9,9) after parturition and 7,4 mouflon km-2 (95% CI: 4,4 -12,5) during rut. Average estimation was 2,440 mouflon after parturition (95% CI: 1,673-3,558) and 2,678 during rut (95% CI: 1,589-4,515). Research highlights: The area represents one of the largest continental free-living populations of mouflon in Europe and a relevant area for Iberian wild goat, where it has survived for centuries and spread into the East Iberia. This study suggests that the survey methods used are suitable and sustainable with available field personnel for quantifying changes in wild goat and mouflon populations, particularly in rugged forest environments. Monitoring should be continued and be part of the development of a comprehensive management programme for Iberian wild goat and mouflon.