The toucan's colorful bill gives new meaning to the phrase cool dude.
Indeed, that gigantic schnoz turns out to be a radiator the rain forest dweller uses to lose body heat.
The bill of the Toco Toucan makes up about one-third of its body length and ornithologists have long wondered about the purpose for the appendage.
Could it be a sexual signal, some snicker.
Maybe a special adaptation to peel fruit, suggest the gourmand set.
Perhaps, the defense minded say, a weapon.
Or, at least, a visual warning to other toucans.
Researchers led by Glenn J. Tattersall of Brock University in St. Catharines, Ontario, Canada, wondered if the big beak might have yet another use — cooling.
After all, elephants use their ears for cooling. So do bunnies. So why not toucan beaks?
The researchers found that the beaks contain lots of blood vessels.
So they photographed the birds — which don't sweat — with heat-sensing cameras.
They found that "the toucan's bill is capable of acting as a thermal radiator of body heat," Tattersall explained.
"By altering blood flow to the bill's surface, toucans can conserve body heat when it is cold, or cope with heat stress by increasing blood flow," he explained via e-mail.
Now, that doesn't mean heat control is the only reason the bill developed, Tattersall cautioned. But it adds to the potential uses.
In demonstrating that a structure like the bill can radiate heat the finding also adds weight to the idea that some dinosaurs used large bony structures to regulate their temperatures.
The Toco Toucan lives in central and eastern South America.