Odor Transmission and Olfaction: the Tuft of the Uropygial Gland and Olfactory Ability in Birds

[摘要] Abstract. The role of olfaction in birds is poorly understood, in part because of our limited knowledge of signal-transmission mechanisms. Here we evaluate the hypothesis that the secretions of the uropygial gland serve as olfactory signals in birds by testing the prediction that size of the olfactory bulb, a proxy for olfactory ability, covaries positively with the size of the uropygial gland's tuft, a circlet of feathers whose size varies extraordinarily from species to species. The function of this tuft has remained a mystery, but mechanical or protective roles are unlikely on the basis that these feathers are downy and always saturated with gland secretion. These observations instead suggest that the tuft may be involved in trapping the compounds produced by the gland's secretions to facilitate conspecifics' perception of odor. We therefore predicted that the uropygial gland's tuft should be more developed in birds with better capacity to smell. Using a dataset of 29 species of birds of 20 families of...

[学科分类] 动物科学

[关键词] birds;coloniality;olfaction;olfactory bulb