Migration may be a high-risk period. In a study involving three species of raptor migrating from Europe to Sub-Saharan Africa, Klaassen et al. (2014) satellite-tracked 51 out of 69 birds to their deaths and showed that rate of mortality during migration was 6x that during stationary phases when birds were on their winter and summer grounds. Travel across the Sahara was particularly risky. Satellite tracking has also been used to infer mortality in other taxa (e.g. sea turtles) and may allow high-risk hotspots to be identified for wide-ranging species.
© 2013 The Author. Journal of Animal Ecology © 2013 British Ecological Society.