Preening and Cleaning
A Whooping crane spends a lot of time caring for its feathers to keep them in top shape for flight. The feathers must last for thousands of miles of flying before new feathers take their place. A crane nibbles at the base of each feather and then zips the entire length of the feather through its bill to repair any gaps in the feather vanes. Growing feathers are itchy. Preening helps open the new feathers and relieves the itch. Preening also helps cranes keep mites, lice, and other parasites and biting insects under control. Also, while they're preening, their skin gets a little exposure to the ultraviolet (UV) light from the sun, and that UV light helps their bodies to manufacture Vitamin D. Finally, cranes spend a lot of time near water—salty water in winter. Their feathers would dry out and get brittle without conditioning oils from their preen gland, located just above the tail. The conditioning oils keep feathers supple and beautiful, the way hand lotion protects skin for people who keep their hands in water a lot. A crane's neck can turn and reach all the way back to the tail to wipe their bill on this important oil.

Brooke Pennypacker, Operation Migration