Ángela Martínez-García et al.
Microbial ecology, 70(4), 1024-1033 (2015-06-17)
Oily secretions produced in the uropygial gland of incubating female hoopoes contain antimicrobial-producing bacteria that prevent feathers from degradation and eggs from pathogenic infection. Using the beak, females collect the uropygial gland secretion and smear it directly on the eggshells