【英语时差8,16】大喙降温（在线收听）

Big Bill Chill When people get hot, we sweat. When dogs overheat, they pant. And birds? At least one type–the Toco toucan–uses its oversized bill to cool down. Even if you’re never seen a live toucan up close, you might be able to picture its huge, multi-colored beak. And you may have wondered…why such a long bill? One study has found that when toucans are too hot, they use their bill to dump heat and cool off. To test this hypothesis, researchers observed toucans in a chamber where the temperature gradually rose by eighteen degrees Fahrenheit. Using thermal imaging, they saw that the hotter the chamber got, the more the birds’ bills warmed up. And as the bills warmed, other parts of the toucans’ bodies either grew cooler or stayed the same. This suggests that toucans channel heat from their bodies to their beaks, which then dump the heat into the surrounding air. Now, a toucan’s bill also serves other purposes, such as picking tropical fruit. But this research shows that, whatever else it might be good for, a toucan’s beak helps it chill out. So is the same true for other birds? Maybe. That’s what scientists are now hoping to discover.