EFFECTS OF AGRICULTURAL LAND-USE ON THE BREEDING OF COLLARED PRATINCOLE GLAREOLA-PRATINCOLA IN SOUTH-WEST SPAIN

The collared pratincole Glareola pratincola is an insectivorous wader with a small and declining breeding population in southern Europe. Asp ects of its breeding performance were studied in a marshland and a far mland colony in south-western Spain. Clutch size was similar in both h abitats but eggs were bigger in the marshland colony. Hatching success was much lower in the farmland colony due to agricultural activities. Food availability was analysed with pit fall traps and sticky traps. Capture rate (number of individuals captured per day) was slightly hig her in marshland than in farmland for pitfalls, but there were no diff erences in insect capture rates by sticky traps. It was not possible t o record fledging success but chicks were fed at the same rate and adu lt attendance and chick growth were very similar in marshland and farm land. Food does not seem to be a constraint to chick rearing in either habitat. Altogether, bleeding performance of birds nesting in marshes was good, while for those breeding in crops egg losses due to agricul tural activities during the incubation period severely reduced chick p roduction. Simple changes to far ming practice might alleviate this pr oblem.