Nest spacing and breeding performance in Short-toed EagleCircaetus gallicusin northeast Greece

Capsule There is some evidence of susceptibility to stochastic or human factors.Aims To describe the phenology and breeding success of one of the densest populations of Short-toed Eagle in Europe.Methods All nests in the Dadia-Lefkimi-Soufli forest in northeast Greece were located and visited regularly throughout the 1996-98 breeding seasons.Data on every stage of the breeding cycle were collected and related to among-year variation in the weather conditions during March to June.Results A total of 58 pairs were located during the three-year study spread across 22 territories (the same territories are usually occupied each year).The nests were evenly spaced (mean of 2.7 km between nests).Adults arrived between mid-March and mid-April.Only one egg per nest was laid.Nestlings fledged on average after 68.9 days.Eagles departed between 8 September and 2 October.Conclusions Arrival date determines laying date.The population size appears to be stable but the species has a relatively low reproductive rate and takes three to four years to mature, consequently it may be susceptible to stochastic or human-mediated factors.