MOVEMENTS OF RADIO-TAGGED BUZZARDS BUTEO-BUTEO IN EARLY-LIFE

Radio-tags were used to track 146 Buzzards Buteo buteo during 1990-199 6. Each bird was tracked for up to 4 years; of 74 Buzzards tagged sinc e 1992, 72% were monitored for more than 3 years, Among the 87 Buzzard s tracked for more than 1 year, 46% settled after one dispersal moveme nt, 37% dispersed and then changed their ranges, 17% did not disperse and one Buzzard alternated between a summer and a winter range. Natal dispersal occurred in two waves, one in the first autumn and the secon d in the following spring, Initial dispersal distances in the autumn w ere significantly greater than those in the spring. For 73 Buzzards th at dispersed in their first autumn, 96% settled within 100 km of their natal nest, and their distances were similar to 76 records from ringi ng, After their second spring, Buzzards rarely changed ranges and were significantly more often to the east than the west, especially those that had dispersed more than 20 km, Buzzards that had dispersed farthe st were most likely to be detected returning towards their natal area each spring and returned earlier as they got older. However, none was detected returning once it had started to breed, Nine early breeders w ere significantly farther from their natal nests than 44 nonbreeders.