Research into Alloanointing in Crested Auklets
Crested auklets nest in large colonies on isolated island cliffs in Siberia and Alaska. These small black and grey seabirds have bright orange bills, with white facial feathers and a prominent feathered crest rising from their foreheads. Recent research carried out on crested auklets nesting on the St. Lawrence Island in the northern Bering Sea off the coast of Siberia, has revealed an interesting courting ritual which, until now, has not been observed in birds.
Hector Douglas, a researcher from the University of Alaska Fairbanks, has concluded from his research that crested auklets secrete a citrus-like scent in wick feathers on their backs. During courtship the birds intertwine their necks in an embrace that rubs this scent on each other. The male initiates the interaction by adopting a horizontal posture and making a soft choking sound. The female accepts the invitation by rubbing her upper body and her bill over the male’s wick feathers, after which she offers her wick feathers to the male. They repeat this action a number of times resulting in spreading the chemicals over their necks, heads and upper bodies. This behavior, known as alloanointing, has been observed in some mammals, but has not been previously documented in birds. Alloanointing seems to serve a two-fold purpose. Firstly it serves as mating signal and secondly, the tick-repelling scent helps protect the birds from parasites in areas that they cannot reach by themselves when preening.
The researcher reached his conclusions by conducting an experiment in which dispensers of the crested auklet’s chemicals were concealed in blocks of construction foam that had been painted to blend in with the rocks. He then placed life size decoys on top of the blocks and waited. Shortly thereafter, the birds approached the decoys with their heads down in a conspicuous sniffing behavior. Once the source of the scent had been identified by the birds, they rubbed their bills over the dispensers and then rubbed themselves on the lifelike decoys right in the area where the wick feathers are situated.
To determine what role alloanointing plays in breeding, the experiment was repeated with captive crested auklets at the Cincinnati Zoo. It was found that, in two successive years, the response to the scent was strongest during early courtship, supporting the idea that birds communicate using scent during courtship periods. Tests were also carried out using the secreted chemicals on ticks, with the conclusion being that alloanointing serves as a protection against parasites, as well acting as a mating signal for the crested auklet.
