This is birdnode.

When summer sizzles, we look for ways to keep cool.

Cypacold one, turn up the air conditioning, or dress down to a pair of shorts and t-shirt.

Birds lack these particular options.

But in the case of the Toko 2 can of South America, evolution has come up with at least one

alternative.

Relative to its body size, the Toko 2 can has the largest bill of any bird in the world.

It's outsized, orange, and accounts for a full third of the body's entire surface area.

It's also laced with blood vessels, and has no insulation.

Features that make it a superb structure for getting rid of excess body heat.

So blood pumps into the bill all the time.

The hotter the weather, the farther out the blood goes, and the heat escapes through the bill's thin outer layer.

This thermal radiation works best when there's a nice breeze, and the 2 can can release virtually all its excess body heat.

That means the Toko 2 can can stay cool even in the sweltering heat of the tropics.

See photos of Toko 2 cans and more on our website, birdnote.org.

I'm Michael Stein.