Birds Sniff Each Other’s Bacteria to Help Choose a Mate

[dufus]

For decades, researchers thought birds lacked a sense of smell. The line of thinking was that scent gets dispersed in the wind, so it’s not the most accurate tool to locate prey or keep tabs on a predator. Instead, other senses, like sight or hearing, became more fine-tuned because smell just wasn’t as necessary. Recently, however, new research has overturned this idea.

 

Now, a new study suggests that not only can birds smell, they identify each other using the unique scent of the microbiome found in their preen glands located at the base of their tail feathers.
 

One way birds stay clean is by spreading around oil produced by the preen, or uropygial, gland. It’s thought that the oil is primarily used to preserve feathers, but previous studies of bird olfaction have also shown that some species communicate using the oil. Researchers have shown that some birds show a preference for certain oily smells, with some songbirds ditching the father of their chicks if a better smelling stud comes along.

 

For a new paper published in the Journal of Experimental Biology, researchers led by Danielle Whittaker, an ornithologist at Michigan State University, investigated how these scents are produced. Several years ago, after giving a talk on her research about birds and scent, a colleague who studies how bacteria help hyenas produce their musk asked if Whittaker had ever looked into birds’ microbiomes.

 

“I had never thought about bacteria at all,” Whittaker tells the New York Times’ Veronique Greenwood. “But all the compounds I was describing were known byproducts of bacterial metabolism.”

 

That's why she decided to see if bacteria were powering the odors in the songbirds she studies. For the study, the team injected antibiotics directly into the preen glands of dark-eyed juncos, a North American songbird, then analyzed how that changed the bacterial communities in the preen oil and subsequently, the odor. They also began culturing the bacteria found in the preen oil of other juncos.

 

They found that all of the bacteria in the birds’ microbiome produce certain scent notes. When combined, the bacteria produce the birds’ personal scent, which in turn has an impact on their mating success.

 

sauce