Potential impacts of off highway vehicles on juvenile northern goshawks

From 2004-2006 we examined the effects of off highway vehicles (OHV) on juvenile northern goshawks (Accipiter gentilis) in the Plumas National Forest, northeastern California. OHV users represent an important demographic of this and other multiple-use forests. California is currently experiencing increased OHV use, yet little study has been devoted to impacts OHV use may have on wildlife and habitat. Additionally, management of goshawks on public lands has largely centered on effects of timber harvest and management activities in nest stands. As part of a multi-phase study attempting to address this dearth of information, we compared survival, space use, and frequency of movement of radio-tagged juvenile goshawks subjected to an OHV treatment and control goshawks that were not subjected to OHV treatment. We focused our examination on the period between fledging and dispersal, when juveniles on a territory remain relatively close to their nest. Preliminary results do not indicate a marked difference between juveniles in treatment and control territories. Conducting radio telemetry in geographically complex terrain combined with typical anthropogenic background sound levels at territories are factors that may have influenced our results. We hope our study promotes scientifically informed decision-making about OHV management relevant to goshawks in multiple-use forests and encourages further research into recreational-use impacts on this and other species.