Whether it's the sudden, plunging dives of Brown Pelicans, the singing and aerial displays of Northern Mockingbirds, or the communal nesting of Purple Martins, innate and learned behaviors are some of the most fascinating things to observe in Texas birds. Even casual birdwatchers eventually ask, "why do they do that?" while serious birders and ornithologists seek to understand all the behaviors involved in feeding, flying, mating, and rearing young...