FORAGING BEHAVIOR AND DIET OF THE ALPINE CHOUGH PYRRHOCORAX-GRACULUS IN THE ITALIAN ALPS IN SUMMER

The foraging behaviour of the Alpine Chough was studied around Cervini a (Aosta, Italy) in June and July 1989 and 1990. The birds foraging in loose flocks (of mean size 32.4) which flew to new foraging patches a t very frequent intervals (median stay time 74.5 s in 1989 and 75.0 s in 1990). The Choughs' peck rates declined significantly through the s ummer, from around 17 items per min in mid-june to around 9 per min in late july. Examination of faeces and regurgitated pellets showed that the most common food items were Orthoptera (grasshoppers) which occur red in 83 % of samples, Coleoptera Curculionidae (55 %) and Elateridae (27 %), invertebrate eggs (26 %), Lepidopteran larvae (24 %), Hymenop tera Formicidae (18 %) and vegetable matter (18 %). Grasshoppers remai ned very small until mid-July and varied greatly in size and density b etween different parts of the study area. The Choughs' very short stay time in any one patch of meadow is consistent with their high intake rates and apparently low costs of movement between feeding sites, but they may also be sampling in a highly variable environment.