3. Birds displаy а wide аrray оf sоcial behaviоrs and mating systems. Choose two species and for each give two examples of traits shaped by social or mating behavior. Explain what the traits are, how they function in social and mating behavior, and whether they are the result of natural and/or sexual selection. In your discussion of natural and sexual selection make sure to differentiate these terms and explain why you conclude that one or both of them are at work.