Picture the most over-engineered tool you own. Now imagine wearing it on your face for life. That's more or less what a toucan (Metazooa animal #1058) does. Its banana-bright bill is so oversized it almost looks fake, but it's one of the most useful pieces of equipment in the rainforest.

First, there's lunch. Many rainforest fruits grow at the tips of thin branches that can't support a bird's weight. A toucan doesn't have to land. It simply stretches out its bill, plucks the fruit, and flicks its head back to swallow it whole. Lizards, eggs, and the occasional unlucky insect are all fair game too.

The bill even doubles as an air conditioner. It's threaded with blood vessels that the bird can open to shed heat or constrict to conserve it. On a hot afternoon, the bill acts like a radiator. On a cool night, it helps keep warmth in.

It's also a social tool. The bright colors help toucans spot one another through the dense canopy and may play a role in choosing mates. They'll fence with their bills, clacking them together in playful contests, and sometimes even toss fruit back and forth like friends passing a ball.

For something so enormous, it's surprisingly light. Inside, the bill is mostly hollow, reinforced by a lattice of keratin that gives it strength without much weight.

So that oversized beak isn't an evolutionary mistake or an extravagant decoration. It's a fruit picker, a cooling system, a signaling device, and a surprisingly elegant piece of engineering—all carried on the front of a bird's face.

Learn more: National Geographic

Monday, June 22 to Sunday, June 28.

The following are the shortest paths from last week:

Play Forgeous for June 29