Monday, November 12, 2007

Prenuptial Perfumery - A Mating Ritual

A small and charismatically billed bird meanders over to another, emits a soft call, and then vigorously rubs its bill over the other bird's back. They exchange full body bill massages and end by entwining their necks. A citrus-like scent fills the air.


These birds are crested auklets, and until recently the purpose of their strange behavior was a bit of a mystery.

Hector Douglas, an assistant professor of biology at the University of Alaska, had been observing the birds while conducting experiments on St. Lawrence Island in the northern Bering Sea. Through a series of ingenious experiments he found out the birds are strongly attracted to an orange-like scent that they secrete in wick-like feathers on their backs.

"They honed in on the scent, rotating their heads to place their nostrils directly over the dispenser. Then they rubbed their bills over the dispensers just as they would on the wick feathers of their partner. Next, the birds rubbed themselves on the lifelike models right in the area where the wick feathers are located,'' he said. "They would engage in prolonged loving on the models."

The birds rub the citrus-like scent on each other during courtship. Each adopts a characteristic posture, a signal to the other that some rubbing is desired.

According to Douglas, this is the first time alloanointing, or the transfer of chemicals, has been documented in birds. A few species of primates have been observed to anoint themselves, but not each other, with various organic compounds they get from breaking open centipedes. They spread the bug juice over their fur, thereby repelling pesky, biting insects.

The crested aukets' alloanointing also serves a practical purpose. Douglas showed the substance they secrete harms ticks. "The ticks exposed to average amounts of citrus scent moved much slower than the controls. They were sluggish, they staggered, and some appeared to be paralyzed,'' he said.

So just how does this help in mating?

Just like people with great hair and skin are more attractive, birds with good quality plumage are more attractive. Just as pimples and frayed hair are turn-offs to people, parasites turn glossy plumage into dull and ragged feathers that are a turn-off to birds.

Because birds can't preen their own heads and necks, those spots are vulnerable to ticks. By roping a partner into feather care, auklets can look better. It's very similar to going to get your hair cut before an important occasion. The birds pay for the service by returning the favor. Such reciprocal exchanges of support reinforce pair bonds.

Crested auklets are not the only ones who can benefit from a little prenuptial perfumery to get rid of the creepy crawlies and keep a budding romantic relationship alive. Viewers of the TV show Desperate Housewives may recall a comical scene aired recently in which Gabby successfully hid her affair with her ex-husband and the fact that she caught crabs from him by allo-anointing her husband. In order to keep her new husband from discovering her infidelity, she had to invent a way to treat his condition without letting him know that she caught crabs and gave it to him too. She turned the application of medicated lotion into a playfully erotic occasion, thus successfully keeping their pairbond alive.

Watch this human version of crested auklet allo-anointing:


The article, Prenuptial perfume: Alloanointing in the social rituals of the crested auklet (Aethia cristatella ) and the transfer of arthropod deterrents, will be published in the German journal Naturwissenschaften.

1 comment:

Wayfarer Scientista said...

huh...strange to come here and then find a report on someone I not only know but whose work I am very familiar with. huh.