Density and biology of the rock-partridge (Alectoris graeca whitakeri) in sicily (Italy)

Abstract

Relative indices (MOT = the average number of birds counted during the trips in the breeding season; ITA = the average number of birds encountered per hour duringthe trips in the breeding season) were used to monitor the rock-partridge breeding population in four areasof Sicily. Statistical analysis of variance demonstrated that the indices are unbiased estimators of the populations under study. The Anova Model II results showed that sampling means were obtained by studying populations of different densities in the chosen areas. The reason for thisdifference is due to the different habitat structure and mainly to the presence-absence of hunting protection. Post-breeding relative indices (MOTpb = the average number of birds encountered during the trips in thepost-breeding season; MIB = the average number of birds gathered in coveys) were also useful in population monitoring. Data on breeding biology show a medium productivity rate (ratio juveniles/adults) of the population. Pair-forming starts in February, egg-laying occurs from March to June, while chicks are present from June to September; average clutch size is 12 eggs. The seasonal development of calling activity through different time bands is also reported. © 1989 Taylor & Francis Group, LLC.