Birds may use smell to select mates

TOULOUSE, France, July 7 (UPI) -- Male and female gulls smell different from each other, and the birds may use body odor to single out genetically compatible mates, French researchers say.

The study published in the journal Naturwissenschaften -- The Science of Nature, looked at how the gulls, known as kittiwakes, protect their feathers by preening them with the secretions of the preen gland, secretions that also carry odors.

Scents tend to vary widely depending on the species, season and/or sex of the bird, the researchers said.

Samples of preen oil from 21 females and 20 males were tested to see if the birds' body odor carried individual and/or sexual signatures that could signal individual genetic makeup.

Kittiwakes tend to choose to mate with genetically dissimilar partners to maintain genetic diversity in the species, but the cues used to assess genetic characteristics are unknown.

The researchers confirmed evidence of individual-specific secretions.

"Our study suggests the existence of two odor signatures in kittiwakes: a sex and an individual signature," Sarah Leclaire from the Universite Paul Sabatier in France said. "These results point to body odor as a signal associated with individual recognition and mate choice. Kittiwakes may be using body odor to assess the genetic compatibility of potential mates."