Do secretions from the uropygial gland of birds attract biting midges and black flies?

Bird susceptibility to attacks by blood-sucking flying insects could be influenced by urogypial gland secretions. To determine the effect of these secretions on biting midges and black flies, we set up a series of tests. First, we placed uropygial gland secretions from blue tit Cyanistes caeruleus broods inside empty nest boxes while empty nest boxes without gland secretions were treated as controls.

Carotenoid-based plumage colouration is associated with blood parasite richness and stress protein levels in blue tits (Cyanistes caeruleus).

Carotenoids are molecules that birds are not able to synthesize and therefore, must be acquired through their diet. These pigments, besides their function of giving birds red and yellow colouration when deposited in feathers, seem to act as immune-stimulators and antioxidants in the organism. Hence, only the healthiest individuals would be able to express carotenoid-based ornaments to a larger extent without compromising the physiological functions of carotenoids.

Testing the use of a citronella-based repellent as an effective method to reduce the prevalence and abundance of biting flies in avian nests.

Here, we validate the use of a citronella (natural oil) based repellent to reduce the abundance of flying blood-sucking insects in avian nests. These insects are important parasites of birds affecting them as blood feeders and as vectors of a diversity of pathogens. When nestling were 10 days old, we assigned wild great tit Parus major nests to one of two treatments, control and fumigated nests.