Birds
Toco Toucan
Ramphastos toco · also called common toucan, giant toucan
The toco toucan is the toucan everyone pictures — glossy black with a white throat and a vast orange bill. That bill is the largest, relative to body size, of any bird, and far from being a burden it is one of the most versatile pieces of equipment in the bird world.
Overview
Unlike most toucans, which are birds of deep rainforest, the toco toucan is a species of semi-open country — the Brazilian Cerrado savanna, gallery forest along rivers, the seasonally flooded Pantanal, woodland edges, palm groves, and plantations across central and eastern South America. This preference for edges and open habitat makes it the most commonly seen toucan and one of the least affected by forest clearance.
The bill
The toco toucan’s bill is about 19 centimetres long, roughly a third of the whole bird, and it does a remarkable amount of work:
- Reach. Perched securely on a thick branch, the toucan can still stretch out to pluck fruit dangling from thin twigs, and probe deep into tree cavities.
- A radiator. The bill’s surface is bare and richly supplied with blood vessels, and the bird can increase or decrease blood flow to it at will — offloading heat on a hot day, conserving it at night. Proportionally, it is one of the largest adjustable “thermal windows” of any animal.
- A tool for nest-raiding. The length lets a toucan reach eggs and chicks inside holes it could not otherwise access.
- Display and play. Toucans fence with their bills, toss food to one another, and preen mates.
Despite its size, the bill is very light — a rigid keratin shell over an air-filled bony lattice — so it barely slows the bird down.
Behaviour
Toco toucans are social, usually seen in pairs or small groups, and noisy, with a repertoire of croaks, rattles, and barks. They fly poorly, moving through the landscape in short flap-and-glide hops. At night they roost communally, contorting into a ball with the bill tucked under a wing and the long tail flipped forward over the back.
Reproduction
Pairs nest in natural tree hollows (they cannot excavate their own) or occasionally in earth banks or termite mounds. The female lays two to four eggs, both parents incubate, and the chicks hatch naked and helpless with the lower bill longer than the upper at first. They stay in the nest for six to eight weeks, fed on a protein-rich mix of insects and small vertebrates as well as fruit.
Status
The toco toucan is Least Concern, widespread, and adaptable, tolerating farmland and disturbed habitat better than forest-restricted toucans. Its main pressures are capture for the pet trade — it is popular and valuable as a cage bird — and hunting for meat and for its bill and feathers, plus localised habitat loss. It remains one of the emblematic and readily encountered birds of the South American savanna.
Toco Toucan: common questions
Why do toucans have such enormous bills?
For a long time this puzzled biologists, including Darwin. Modern work suggests the bill does several jobs at once. It lets the bird sit on a sturdy perch and still reach fruit on thin outer twigs, and reach into tree holes to raid other birds' nests. It probably intimidates rivals and nest predators. And crucially, it works as a large, bare, blood-rich radiator — a toco toucan can route warm blood into the bill to dump excess heat, or restrict it to stay warm, adjusting its "thermal window" more than almost any other animal. It is also used in social play, with birds fencing and tossing fruit to each other.
Is a toucan's bill heavy?
Surprisingly light. Although it looks solid, the bill is a thin shell of keratin over a strut-braced core of bony foam full of air pockets, so the whole structure is only about 5% of the bird's weight. This lightweight, rigid, energy-absorbing design has been studied by engineers interested in strong, low-mass materials.
Can toucans fly well?
Not far or gracefully. The big bill and short, rounded wings make sustained flight hard work, so toco toucans travel mostly by a series of short, laboured flap-and-glide hops between trees, and they hop rather than walk along branches. Within a patch of woodland they get around fine; they just do not undertake long journeys.
What do toucans eat besides fruit?
Fruit is the bulk of the diet, and toucans are important seed dispersers, swallowing fruit whole and passing the seeds. But they are opportunistic omnivores that also take insects, spiders, lizards, frogs, and — regularly — the eggs and nestlings of other birds, using the long bill to probe into nest holes. Young toucans are fed a diet especially high in this animal protein.