Measuring the eye size of mist-netted birds: a comparison of two non-invasive methods

摘要

Relating eye size differences in birds to aspects of ecology and life history features offers interesting views on selective forces shaping eye size. However, data on eye size is hardly available. We compare two non-invasive methods for measuring theeye sizes of live birds: measures obtained using photos with a scale of the heads of mist-netted birds and published data based on measurements using a caliper. Both methods produced nearly identical data. Hence, we recommend using photos for measuring eye size instead of using a caliper, thereby—amongst other advantages—minimizing the risk of damaging the bird's eye.