London, Dec 2 (IANS): Austrian scientists have found the first evidence that birds may choose their mate through odour.

“When birds groom themselves, they spread chemical compounds from their preen glands throughout their plumage. These chemicals produce odours that appear to be unique to each individual, providing an olfactory fingerprint,” explained Richard H. Wagner from the Konrad Lorenz Institute of Ethology, a part of the Veterinary Medicine University Vienna.

The researchers also compared the preen gland chemicals of black-legged kittiwakes with genes that play a role in immunity.

Kittiwakes that smell similar to each other also have similar genes for immunity.
The team suspected that just as in mammals, these odours may be used by kittiwakes to assess their relatedness to other individuals.

They collected both DNA samples and preen gland odour samples from nesting kittiwakes.

The findings showed that individual kittiwakes that smell similar to each other also have similar “major histocompatiabilty complex (MHC) genes that help individuals resist diseases.

Closer relatives, therefore, have more similar odours than distantly related individuals.

“This suggests that birds may be able to compare their own odour with those of potential mates and to choose unrelated individuals as breeding partners,” ornithologist Wagner suggested.

The new findings open the door for further work linking mate choice and disease-resistance in birds.

The scientists published their findings in Nature’s Scientific Reports.