THE ANIMAL FILES

Toco toucan

Ramphastos toco

A toucan’s bill can shed heat as well as handle food.

Toco toucans feed mainly on fleshy fruit, but also take insects and other animal food. The large bill has a blood-vessel network that changes heat exchange. Tree-to-tree movements connect fruiting patches that shift through the year.[1]

Follow the evidence ↓
Toco toucan
Image: Giles Laurent · Commons · CC BY-SA 4.0
Main food
Fleshy fruit[1]
Bill function
Food handling and heat exchange[1]
Movement
Between feeding trees and habitats[1]

A controllable heat surface

Blood flow through vessels near the bill surface can be modified, changing heat released to the air. The keratin covering is thin over that vascular network. Tucking the bill beneath a wing may reduce heat loss during rest. This is a physiological function alongside feeding, not proof that every large bill evolved for one purpose alone.[1]

Fruit first, not fruit only

Figs and many other fleshy fruits are eaten. Insects, eggs and nestlings also supplement the diet. Fruit availability varies among habitats: birds can remain where supply is steady or move as particular trees finish fruiting. A generalist fruit-eater still needs a landscape with changing food patches.[1]

Travelling between treetops

Birds hop among branches and alternate flapping with gliding in flight. Feeding can occur alone or in small groups; larger gatherings also occur after breeding. When moving together, a group may proceed between treetops in single file.[1]

A COMMON MIX-UP

Is the large bill useful only for picking fruit?

No. Controlled blood flow also makes it a heat-exchange surface.[1]

TRY A LITTLE REASONING

Why could hiding the bill under a wing change heat loss?

Reveal the explanation

It reduces exposure of a vascular heat-exchange surface to surrounding air.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Ramphastos toco (adapted and translated; exact revision)
  2. NCBI Taxonomy — Ramphastos toco (identity and game lineage)

Last fact check:

One discovery leads to another

Pileated woodpeckerA tree can be a feeding site, a drum and a future home.Dryocopus pileatus ↗Common hoopoeA long bill can open while it is already inside the soil.Upupa epops ↗Andean condorA huge bird can travel on rising air.Vultur gryphus ↗