Tough Toucans; anything but clowns!

A quick search of the internet will reveal plenty of anthropomorphic throw-away lines like "it's impossible to take toucans seriously". That could only be written by someone who's never watched wild toucans, stunningly beautiful and clearly intimidating to many of their neighbours. I suspect the authors of such lines are much more familiar with the clownish caricatures of toucans from cartoons and advertising logos.

Yellow-throated (also called Black-mandibled) Toucan Ramphastos ambiguus, Wild Sumaco Lodge, Ecuador. At 60cm long and up to 750 grams, this is one of the largest toucans,
and is found from southern Peru to Central America. This one was about to tuck into the
cluster of long Cecropia fruits behind it - toucans are great fruit eaters.
The colourful plumage, bill and bare facial skin are typical of toucans.

Chestnut-eared Aracari Pteroglossus castanotis, Iguaçu Falls, Brazil.
The aracaris, all in the same genus, are a group of 14 smaller toucans found throughout the Neotropics.
This one is less than half the weight of the previous species and is usually found near water.

There are some 45 species recognised, all in the Family Ramphastidae, found throughout tropical South and Central America, except for the Pacific desert coast. All are solely or mostly rainforest birds, except for the largest and probably most-recognised of them all.

The Toco Toucan Ramphastos toco, here in the northern Pantanal of Brazil, is found in
drier woodlands and savannahs of eastern and central South America. Most toucan
caricatures are based on this magnificent bird, which is also the largest toucan, more
than 60cm long and weighing nearly 900 grams. The remarkable bill is the largest in area,
for body size, of any living bird. It can have an area up to half that of its body surface.
It was this bill (ie the Toco's) that was studied to reveal the surprising role of toucan bills in heat loss - see below.

While we're on Tocos, the Pantanal is probably the best place to see them. This is part of a group
of a dozen or so which gathers outside the kitchen door in the early mornings at Pousada Aguapé
in the southern Pantanal.

All toucans rely on hollows for nesting. While some of the big ones can do some enlarging of soft rotted wood, for the most part those bills aren't useful for such heavy work, though some of the green toucanets, small toucans in the genus Aulacorhynchus, can manage it. Accordingly most need to find a large tree cavity which is either natural or been excavated by someone else.

Plate-billed Mountain Toucan Andigena laminirostris, north-western Ecuadorian Andes, at nesting hollow.
(And this one wouldn't let me get a better angle!)

However, so much of toucan lore is about the bill, unsurprisingly. Obviously one major function is food-gathering. As mentioned, toucans are fundamentally fruit-eaters, targetting a wide range of fruiting trees; as such they are very important vectors of seeds of rainforest trees and climbers.

Yellow-throated Toucan eating Cecropia fruits, Wild Sumaco, Ecuador. This is the bird featured in the first photo above.
(And Wild Sumaco really has one of the best balconies for wildlife viewing that I've ever seen!)

This fondness for fruit also makes toucans regular visitors to feeders throughout much of their range, enabling closer views of wild toucans than we would ever be likely to get otherwise.

Pale-mandibled (or Pale-billed) Aracari Pteroglossus erythropygius, Mirador Rio Blanco,
north-west of Quito, Ecuador. This is a restaurant with huge views over the river valley
and great feeders on the edge of the forest just the other side of the windows.
We can watch the birds at the buffet while we're eating our own lunch!

However most toucans are also fond of some meat in their diet. Many rob nests, both by probing into tree hollows and ripping apart hanging nests such as those of caciques; birds regularly mob them to try to move them on. They will also hunt almost anything they can catch on occasions, from insects to small birds, lizards, frogs, snakes and small mammals. 

As can be seen in some of the photos, including the previous one, many toucans have forward-pointing 'teeth' in the upper mandible. While it is often asserted that the purpose is to rip fruit apart, there appears to be no evidence to support this. Others suggest that they might be to assist in intimidatory postures, such as defending a fruiting tree, or warding off mobbing birds trying to prevent nest robbing, but while these activities certainly occur, there again seems to be no evidence of the bill 'teeth' playing a role in this. The aracaris seem to have the most-developed bill teeth; here are a couple more examples.

Chestnut-eared Aracari, Pousada Arara, northern Pantanal; these are common visitors to feeders.

Collared Aracaris Pteroglossus torquatus (very wet!), Costa Rica. This aracari is found throughout
Central America and adjacent far northern South America. Here the 'teeth' are evident
on the lower mandible too. These birds too were attracted by free bananas at a private feeder.

The bright colours of the bill - evident in some of the photos in this posting - also suggest a role in courtship displays.

 

However, recent work has shown that another purpose of the bill, and possibly the major one, is to disperse heat, a key problem for any tropical bird, especially a larger one, given that birds don't sweat and have limited bare skin. Toucans have complex blood networks in the bill, which can be opened or closed to control blood flow near the surface, restricting it to conserve heat, increasing it to shed heat. Infrared thermal imaging showed rapid heat transfer from the body to the bill - such as when the bird was about to sleep - and equally rapid 'dumping' of this heat from the bill to the atmosphere. (More recently, acting on this tip-off, other workers have confirmed that hornbills, an unrelated Old World group of big-bills, do exactly the same thing.)

I'm going to end this introduction to the wonderful toucans by featuring more examples of the three groups (representing genera) that we've already met, plus the two that we haven't yet encountered here. I've included a couple of fairly ordinary photos in order to share as many toucan species as possible.

The big 'typical' toucans, such as the Yellow-billed and Toco above, are all in the genus Ramphastos (from which the family is also named). Here are three (or maybe four?) more of them, of the eight generally recognised.

Choco (not to be confused with Toco!) Toucan Ramphastos brevis, Rio Silanch, north-west of Quito, Ecuador.
The Choco is a hugely biodiverse region of western Colombia and Ecuador.

Green-billed (or Red-breasted) Toucan Ramphastos dicolorus, Trilha dos Tucanos Lodge, near Sao Paulo, Brazil.
This lovely toucan is limited to south-eastern Brazil and adjacent Argentina and Paraguay.

Channel-billed Toucan Ramphastos vitellinus, Chapada dos Guimarães NP, south-western Brazil.
This blue-faced beauty (which was being very coy) is limited to north-eastern South America.

The Chestnut-mandibled Toucan, here at Milpe Reserve, north-west of Quito in Ecuador,
is usually regarded as a sub-species of the Yellow-Billed Toucan (see the black-billed form in the
first photo), but some would raise it to full species R. swainsonii.

The aracaris (genus Pteroglossus) form the largest toucan group, with 14 species; as well as the three above, here are four more.

Ivory-billed Aracaris Pteroglossus azara, from the rainforest canopy tower at Sacha Lodge, Ecuadorian Amazonia.
(Distant preening birds with my first digital camera, a bit primitive by today's standards.)
A toucan primarily of the lowland Amazon rainforests.

Lettered Aracari Pteroglossus inscriptus, Chapada dos Guimarães NP, south-western Brazil.
The name refers to the bill markings, not very obvious in this, another distant, photo.
The bird is found from Bolivia to the north Atlantic coast of Brazil.
It is the smallest toucan, less than 30cm long and weighing only 130 grams.

Many-banded Aracari Pteroglossus pluricinctus, another great sighting from the Wild Sumaco balcony in Ecuador
(see above)!  Here at its south-western limits, it extends east across much of northern South America.

I think this Saffron Toucanet Pteroglossus bailloni is one of the loveliest and most striking of all toucans -
it is so different from all the rest. This one also came for the bananas at Trilha dos Tucanos, near Sao Paulo (see
Green-billed Toucan above). It used to be put in its own genus to reflect its 'differentness', but it is
now regarded as an aracari. It is almost endemic to south-eastern Brazil, just sneaking into Argentina and Paraguay.

The mountain toucans are a small genus of four species from the Andean cloud forests. We met Plate-billed earlier from Ecuador; here's another.

Grey-breasted Mountain Toucan Andigena hypoglauca, El Cajas NP, southern Ecuador.
Its range is a narrow strip of the Andes from Colombia to Peru.

There are 11 of the  little green toucanets, genus Aulacorhynchus.

Crimson-rumped Toucanet Aulacorhynchus haematopygus, Mirador Rio Blanco, Ecuador.
(See the Pale-mandibled Aracari above for a little more on this excellent feeder of birds and people!)
Lovely, like all this genus of little treasures; sadly we can't admire its rump here...

Finally there are six of the 'dichromatic toucanets', genus Selenidera. The name refers to the fact that almost alone of the toucans, they have differently coloured sexes (in most of the rest the females have smaller bills, but are otherwise pretty much indistinguishable from their mates).

This handsome pair were among the amazing throngs in front of the Wild Sumaco balcony in the eastern Andean slopes of Ecuador.

Golden-collared (or Red-billed) Toucanets Selenidera reinwardtii, female above and male below;
without prior knowledge, they could easily be mistaken for separate species.

They are found in mostly lower-slope forests around the junction of Colombia, Ecuador and Peru.
In fact members of this genus are strongly forest-oriented, so are a good indicator of the health of the forests.

Well that's it for today. I hope this small offering has helped to lift the toucans off the cereal box, stout bottle label and cartoon strip, and back to their special place in the world. They really are much more than just a caricature!

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