How Toucans Stay Cool

The Toco Toucan of South America has evolved to stay cool in the sweltering heat of the tropics. Relative to its body size, the Toco Toucan has the largest bill of any bird in the world, accounting for a third of the body’s entire surface area. It’s also laced with blood vessels and wholly without insulation — features that make it a superb structure for getting rid of excess body heat.

Listen to this show in Spanish here.

BirdNote^®

How Toucans Stay Cool

Written by Bob Sundstrom

This is BirdNote.

[Calls of the Toco Toucan]

When summer sizzles, we look for ways to keep cool. Sip a cold 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 Toco Toucan of South America, evolution has come up with at least one alternative.

[Calls of the Toco Toucan]

Relative to its body size, the Toco Toucan 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 toucan can release virtually all its excess body heat. That means the Toco Toucan can stay cool even in the sweltering heat of the tropics.

[Calls of the Toco Toucan]

###
Bird sounds provided by The Macaulay Library of Natural Sounds at the Cornell Lab of Ornithology, Ithaca, New York. Toco Toucan ML 132572 recorded by Peter A. Hosner.
BirdNote’s theme music was composed and played by Nancy Rumbel and John Kessler.
Producer: John Kessler
Executive Producer: Sallie Bodie
© 2016 Tune In to Nature.org August 2018/2019/2021 / July 2023

Narrator: Michael Stein

ID# toucan-02-2021-8-15 toucan-02

Reference: https://www.researchgate.net/publication/26692147_Heat_Exchange_from_th…