Population Response to Habitat Management from an Endangered Galliform: The Pyrenean Grey Partridge Recovery Project in Lago de Sanabria (2000–2023)

Abstract

The Pyrenean grey partridge (Perdix perdix hispaniensis) is an endangered and insufficiently studied galliform occurring in upland habitats dominated by shrublands in Spain, France, and Andorra. Aiming to develop tailored management to favour the species, we studied the effect of habitat management on a partridge population located in Zamora province within the Galician–Duero mountains as part of a long-term project promoted by the regional government (Junta Castilla y León). Management was based on carrying out conservation and recovery of optimal habitats through clearing shrublands (either plots or linear) distributed in a “core area” of 45 km2, conducting tracks with beaters and pointing dogs during autumn in three areas, and comparing the partridge abundance before (2000–2006) and after (2007–2023) management. Habitat management increased partridge abundance values in two areas (1.46 and 1.68 times higher) and had no effect on the remaining one. The pattern of grey partridge abundance during the study was irregular and not influenced by the weather, and the highest abundance values were reached 8–10 years after habitat measures were implemented for the first time. Habitat management allowed high autumn abundance to be reached (mean kilometre abundance values of 2.94 and 3.74 birds/km in two areas), while the mean number of birds per family group was not affected by management (nine birds/group). When aiming to recover Pyrenean grey partridge populations, habitat management should be based on the conservation and management of shrublands to provide mixed habitats in the medium and long term, ensuring regular partridge monitoring.