What can the mating behavior of birds tell us about evolution, climate change and species survival? For Peter Dunn, UWM distinguished professor of biological sciences, bird-watching offers clues to overarching ecological questions. He wants to know the purpose behind bird preferences such as feather brightness and why some birds follow the same mating playbook, while others deviate. He and Professor Linda Whittingham are now in their 21st year of studying tree swallows at the UWM Field Station, a 320-acre wetland near Saukville. This has given the ornithologists a long-term perspective on the birds they study, which include common yellowthroats and tree swallows.