The Keratin Killers: An Analysis of Feather Degrading Bacteria on Idaho Raptors

Feather-degrading bacteria (FDB) degrade the b-keratin matrix of bird feathers. This damages functions that rely on feather integrity including flight, thermoregulation, and mate attraction. Burtt and Ichida (1999) found more FDB in ground foraging birds when compared to aerial insectivores and bark-probers, which was likely related to the soil-dwelling nature of FDB. Burrowing owls (Athene cunicularia) nest underground in burrows dug by fossorial mammals and spend substantial time on the ground exposed to soil. Thus, we hypothesized they would be especially susceptible to FDB. We compared FDB in burrowing owls to other birds of prey species that nest in tree cavities or other above-ground situations. We used Q-swabs to sample feathers of each species and collected 4-5 feathers from each individual to evaluate FDB through swabbing and full feather hydrolysis. Samples were plated on feather meal agar, a media that selects for keratinase activity, from which we quantified colony-forming units. Individual colonies were sequenced and speciated. We also conducted qPCR using 16S and keratinase-specific primers to determine the ratio between FDB and total bacteria load for each species