Red-legged Patridge (Alectoriss rufa) age and sex ratios in declining populations in Huesca (Spain) applied to management

Abstract

In two areas of the district of Huesca (Spain) the age and sex ratios of declining Red-legged Partridge (Alectoris rufa ) populations were studied between 1985 and 1987, and were compared with data found in previous studies. Declining Red-legged partridge populations in the Province of Huesca, in contrast to stable ones, are characterized by age ratios < 1 while sex ratio and adult sex ratio > 1 due to poor habitat quality (ecotone absence, low diversity, and great agricultural impact), overabundance of antropophilous predators and excessive hunting pressure, which reduces the survival of hens and chicks. Unfavourable yearly climate variations induce mortality of juvenile and adult hens. Bag limits must consider not only density, but also population structure and habitat quality. Habitat restoration, bag management, and antropophilous predator control are necessary as well as urgent measures to guarantee the viability of Red-legged Partridge populations.