Yesterday a lone mourning dove came to my urban (NYC) rooftop garden to sunbathe, and, it wasn't an attempt to work on her suntan!
Sunbathing is an option mourning doves use to maintain their feather quality to keep them in top shape for flying. According to WBU in Michigan, "In late summer doves are growing new outer feathers... the heat of the sun might help make it easier for doves to shape their new feathers. And along with easing discomfort associated with molting, the sun may also help dislodge parasites so the bird can preen them off more easily."
ADENMENDUM: As of March 2, 2018, Words In Our Beak Volume One, is no longer available in the digital options listed here. A new digital option should be available sometime in the near future. Updates will be made when this happens, please stay tuned.