Study demonstrates seasonality of bird migration in response to environmental cues

see www.sciencedaily.com/releases/2016/09/160906131436.htm

“A University of Oklahoma study demonstrates for the first time that remote sensing data from weather surveillance radar and on-the-ground data from the eBird citizen science database both yield robust indices of migration timing, also known as migration phenology. These indices can now be used to address the critical gap in our knowledge regarding the cues that migrants use for fine tuning their migration timing in response to climate.”