This is Bird Note.

Crested oclates are small sea birds that nest on remote cliffs in the northern Pacific

and the Bering Sea.

But it's their smell that really sets these birds apart.

They smell like tangerines.

Native peoples of the Bering Sea Islands have known about this for a long time, but for

some reason early European and American naturalists who carefully describe the region's wildlife

in every other way never commented on the bird's distinctive odor.

Now that whiff of citrus on the salt air has become big news in the study of birds.

That's because the scent, which is only produced during the breeding season, is a rare example

of a bird producing an odor to entice mates.

A female inspects a potential mate by pushing her beak into a male's neck feathers,

where his special scent is concentrated.

It appears to be a crucial sniff test.

Field experiments show that females go for males who emit the strongest scents.

Scientists think this scent could have other purposes too.

The birds give off the odor more strongly when they're stressed.

And this smell seems to also help keep parasites away.

For a long time, scientists thought that most birds didn't rely much on their sense

of smell at all, but over the last few decades, that's changing.

For Bruno, I'm Mary McCann.