Démographie comparée d’une population de perdrix bartavelle (Alectoris graeca saxatilis) et d’une population d’hybrides (A. g. saxatilis x A. rufa rufa) dans les Alpes-Maritimes

Abstract

The demography of two partridge populations was compared during 4 years in southern French Alps : a population of Rock partridge Alectoris graeca saxatilis living at high elevations and a population of hybrids between Rock partridge and Red-legged Partrige A. rufa rufa inhabiting middle elevations. Spring densities and reproductive success were higher in the hybrid population. Survival rates were estimated for chicks and older birds from telemetry data collected in the hybrid population. Raptor predation was the major cause of death throughout the year, but during winter mammalian predation and starvation also occured. Starvation, provoked by deep snow, contributed to the low survival rate recorded from November to April (34 %). Radio-telemetry was useful in studying the recruitment of young males to the breeding segment of the population, the double nesting of certain hybrid females, and the incubation by the hybrid male of one of the two clutches. Counts in May and August and radio-tracking must be continued at least for two additional years to confirm these preliminary results. Moreover rock partridges should also be radio-tracked at high elevation to study their behavior, reproductive success and survival, and to compare the dynamics of hybrid and non-hybrid populations.