Evidence for deleterious effects of harness-mounted satellite transmitters on Saker Falcons Falco cherrug

Abstract

This study identifies lethal and sub-lethal effects associated with the deployment of harness-mounted satellite transmitters on a large falcon species.Aims We examined the effect of harness-mounted satellite transmitters and patagial tags on survival, behaviour and physical health of adult Saker Falcons.Methods We compared breeding turnover of Saker Falcons deployed with harness-mounted satellite transmitters or patagial tags with unmarked birds identified by using genetic markers. In addition, observational data were recorded on the breeding behaviour and physical condition of birds with satellite transmitters.Results This study found evidence of decreased survival, together with sub-lethal behavioural and physical effects, associated with the deployment of harness-mounted satellite transmitters on Saker Falcons. We found no effect of fitting patagial tags on breeding turnover, although the removal of patagial tags by several birds may have indicated they caused some degree of discomfort.Conclusion Researchers using harness-mounted transmitters on this, and similar, falcon species need to assess how these deleterious effects may impact on species conservation, the welfare of individual birds and the interpretation of their studies.