Bac­te­ria and the Sin­gle Auk­let

by Elio

Crested Auk­lets are arc­tic seabirds that use smell for so­cial func­tions. This wouldn't ex­actly be news for any other group of an­i­mals, but it is a first for birds – those feath­ered crea­tures which can both smell and be smelly. These par­tic­u­lar monog­a­mous birds have a species-spe­­cific tan­ger­ine-like odor that at­tracts their mates. The ques­tion arises, where do the chem­i­cals re­spon­si­ble for this scent (mainly cis-4-de­ce­nal and oc­tanal) come from?

Crested Auk­lets. Source

A re­cent study pro­poses that the ori­gin of these at­trac­tants may well be the cleav­age of long-chain fatty acids by bac­te­ria. The mi­cro­bial as­sem­blages on the feath­ers of these an­i­mals are quite dis­tinctive, as judged by cul­ture-in­de­pen­dent mol­e­c­u­lar tech­niques. Two gen­era, Psy­chrobac­ter and Paeni­bacil­lus, were found on auk­let feath­ers but not on blue­birds, finches, or chick­ens. Psychro­bacter makes spe­cial sense, be­ing both cold and salt tol­er­ant. In­ter­est­ingly, Psy­chrobac­ter was not found on the closely-re­lated Least Auk­let which lacks the tan­ger­ine-like scent. Fur­ther work is needed to con­firm the pos­si­ble con­tri­bu­tion of bac­te­ria to the sex life of these at­trac­tive birds.