Evaluating relocation as a vulture management tool in north Florida

Abstract

As distributional patterns of black vultures (Coragyps atratus) and turkey vultures (Cathartes aura) change, and as woodland habitat declines, vultures increasingly come in contact with human activity. Relocation of problem birds is one potential management approach for resolving conflicts. Relocation involves trapping and moving the vultures some distance away where their subsequent behavior is not expected to conflict with human activity. To evaluate vulture responses to relocation, we trapped and patagial-tagged 114 vultures at two roosting areas over a period of ten months and equipped ten of them with satellite transmitters. Of 9,101 locations, 18.6% had a measure of accuracy of 1000 m to <150 m. The remainder had an accuracy of >1000 m of accuracy (n=3149), no estimate of location accuracy (n=2024), or invalid location (n= 1117). Two transmitters were recovered due to removal or illness of the bird, were reset, and deployed on different vultures. Sixteen tagged birds were sighted after their release. Half of the sighted birds were observed at their unmodified trap site, and four of eight birds with transmitters were tracked to within 16 km of their trap site. No birds have been tracked to or seen at the modified trap site. One bird was tracked to within 32 km of its modified trap site. Birds took an average of eight months to return to the trap site. Relocation appears to be effective in the short term, but habitat modification and harassment to render the location unattractive is necessary for successful long-term removal of problem vultures.