You don’t usually want to get too close to a colony of seabirds, unless you really enjoy the smell of bird excrement. But perhaps smelling a crested auklet colony wouldn’t be so bad — the highly social Alaskan seabirds (right) give off the citrusy scent of tangerines during their breeding season. And that odor may be more than just a pleasant-smelling anomaly. Julie Hagelin of Swarthmore College and her team reported in the Proceedings of the Royal Society last month that the auklets may use that scent as a communication device. Though odors are a common form of communication in other vertebrate animals, this is the first study to show that birds might use it, too.
When they meet, auklets press their bills against each other’s neck feathers, where the smell is strongest. The researchers speculate that auklets use the smell to help pick out mates: well-fed birds may produce more scent. Experiments showed that the auklets are reliably attracted to that smell, preferring it to animal musk, banana essence, or an odorless control. Hagelin stated in a press release: “Our results provide support for an entirely new mode of signaling in birds, that of chemical communication. It is a means of interpreting bird behavior that is just beginning to be realized.”