The autumn diet of the rock partridge Alectoris graeca saxatilis in the southern sector of the French Alps

Abstract

The autumn diet of the Rock partridge Alectoris graeca saxatilis in the southern sector of the French Alps (Alpes-Maritimes) is described, based on 114 crop contents collected between 1981 and 1983. Seventy five per cent, dry weight, of the crop contents were made up of vegetable food, including green plant parts, dry fruits and seeds. Animal prey, mostly Orthoptera (Caelifera and Ensifera) , made up ca 25 per cent of the diet. Juvenile partridges, however, ate more animal food than adults. The rock partridge's diet varied from one year to the next, apparently depending on the amount of rainfall in autumn which influences the availability of food. Altitude also plays a role ; the diet was more varied at middle elevations (1 000-1 900 m) than higher up (1 900-2600 m), reflecting the higher plant species richness at middle altitudes. The possibility that rock partridges deliberately select in autumn dry fruits, seeds and (at higher elevation) animal prey, rather than fresh plants parts, is discusse