All routes are not created equal: an ungulate’s choice of migration route can influence its survival

1. Our knowledge of migration ecology has progressed quickly in concert with technological advances that collect fine-scale movement data through time. We now know that migration plays a critical role in the annual nutritional cycle of large herbivores and that sustaining functional migratory routes is key to long-term conservation. Yet, we lack basic information on whether one migratory route may function better than another, or more specifically, if choosing one route over another has fitness consequences – knowledge that could help inform conservation and restoration efforts.
2. Here, we examined how a suite of migratory parameters influenced the survival of mule deer (Odocoileus hemionus) that shared a common winter range in New Mexico, USA, but migrated to various summer ranges in Colorado, USA. We used a Cox proportional hazard model and GPS data collected over a 7-year period to investigate whether the mortality risk of 66 deer was affected by choice of migratory route, summer r...