Toucans (/ˈtuːkæn/,UK:/-kən/) areNeotropical birds in the familyRamphastidae. They are most closely related to theToucan barbets. They are brightly marked and have large, often colorfulbills. The family includes fivegenera and over 40 differentspecies.
Toucans arearboreal and typically lay two to four whiteeggs in their nests. They make their nests intree hollows and holes excavated by other animals such aswoodpeckers—the toucan bill has very limited use as an excavation tool. When the eggs hatch, the young emerge completely naked, without anydown. Toucans are resident breeders and do notmigrate. Toucans are usually found in pairs or small flocks. They sometimes fence with their bills and wrestle, which scientists hypothesize they do to establish dominance hierarchies. InAfrica andAsia,hornbills occupy the toucans'ecological niche, an example ofconvergent evolution.[1]
The name of this bird group is derived from theTupi wordtukana or theGuaraní wordtukã,[2] viaPortuguese.[3] The family includes toucans,aracaris and toucanets; more distant relatives include various families of barbets andwoodpeckers in the suborderPici.
Toucans range in size from thelettered aracari (Pteroglossus inscriptus), at 130 g (4.6 oz) and 29 cm (11 in), to thetoco toucan (Ramphastos toco), at 680 g (1.50 lb) and 63 cm (25 in). Their bodies are short (of comparable size to acrow's) and compact. The tail is rounded and varies in length, from half the length to the whole length of the body. The neck is short and thick. The wings are small, as they are forest-dwelling birds who only need to travel short distances, and are often of about the same span as the bill-tip-to-tail-tip measurements of the bird.
The legs of the toucan are strong and rather short. Their toes are arranged in pairs with the first and fourth toes turned backward. The majority of toucans do not show anysexual dimorphism in their coloration, the genusSelenidera being the most notable exception to this rule (hence their common name, "dichromatic toucanets"). However, the bills of female toucans are usually shorter, deeper and sometimes straighter, giving more of a "blocky" impression compared to male bills. The feathers in the genus containing the largest toucans are generally purple, with touches of white, yellow, and scarlet, and black. The underparts of thearaçaris (smaller toucans) are yellow, crossed by one or more black or red bands. The toucanets have mostly green plumage with blue markings.
The colorful and largebill, which in some large species measures more than half the length of the body, is the hallmark of toucans. Despite its size, the toucan's bill is very light, being composed of bone struts filled withspongy tissue ofkeratin[7] between them, which take on the structure of abiofoam.[8] The bill has forward-facingserrations resembling teeth, which historically led naturalists to believe that toucans captured fish and were primarily carnivorous; today it is known that they eat mostly fruit. Researchers have discovered that the large bill of the toucan is a highly efficientthermoregulation system, though its size may still be advantageous in other ways.[9][10] It does aid in their feeding behavior (as they sit in one spot and reach for all fruit in range, thereby reducing energy expenditure), and it has also been theorized that the bill may intimidate smaller birds, so that the toucan may plunder nests undisturbed (seeDiet below). The beak allows the bird to reach deep into tree-holes to access food unavailable to other birds, and also to ransack suspended nests built by smaller birds.
A toucan's tongue is long (up to 15 cm or 6 in), narrow, grey, and singularly frayed on each side, adding to its sensitivity as a tasting organ.
A structural complex probably unique to toucans involves the modification of several tailvertebrae. The rear three vertebrae are fused and attached to the spine by aball and socket joint. Because of this, toucans may snap their tail forward until it touches the head.[11] This is the posture in which they sleep, often appearing simply as a ball of feathers, with the tip of the tail sticking out over the head.
Toucans are native to the Neotropics, from Southern Mexico, through Central America, into South America south to northern Argentina. They mostly live in the lowland tropics, but the mountain species from the genusAndigena reach temperate climates at high altitudes in the Andes and can be found up to thetree line.[12]
For the most part the toucans are forest species, and restricted toprimary forests. They will entersecondary forests to forage, but are limited to forests with large old trees that have holes large enough to breed in. Toucans are poor dispersers, particularly across water, and have not reached the West Indies. The only non-forest living toucan is the toco toucan, which is found in savannah with forest patches and open woodlands.[12]
Behaviour and ecology
Toucans are highly social and most species occur in groups of up to 20 or more birds for most of the time. Pairs may retire from the groups during the breeding season, then return with their offspring after the breeding season. Larger groups may form during irruptions, migration or around a particularly large fruiting tree.[12]
Toucans often spend time sparring with their bills, tag-chasing, and calling during the long time it takes for fruit to digest. These behaviours may be related to maintenance of the pair bond or establishing dominance hierarchies, but the time required to digest fruit, which can be up to 75 minutes and during which the toucan can not feed,[13] provides this time for socializing.[12]
Diet
Toucans, like thisred-breasted toucan (Ramphastos dicolorus), nest in hollows in trees
Toucans are primarilyfrugivorous (fruit eating), but are opportunisticallyomnivorous and will takeprey such asinsects, smallerbirds, and smalllizards.[14] Captive toucans have been reported to hunt insects actively in their cages, and it is possible to keep toucans on an insect-only diet. They also plunder nests of smaller birds, taking eggs and nestlings.[15][16] This probably provides a crucial addition of protein to their diet. Certainly, apart from being systematically predatory as well as frugivorous, like many omnivorous birds, they particularly prefer animal food for feeding their chicks.[17] However, in their range, toucans are the dominant frugivores, and as such, play an extremely important ecological role asvectors for seed dispersal of fruiting trees.[18][19]
Breeding behaviour
Toucans nest in cavities in trees, and the presence of suitable trees is a habitat prerequisite for toucans. For the most part toucans don't excavate nesting cavities, although some green toucanets do.
Calls
Toucans make a variety of sounds. The very name of the bird (fromTupi) refers to its predominant frog-like croaking call, but toucans also make barking and growling sounds. They also use their bills to make tapping and clattering sounds. Mountain toucans are known for donkey-like braying.[20]
Relationship with humans
The toucans are, due to their unique appearance, among the most popular and well known birds in the world.[12] Across their native range they were hunted for food and also kept as pets, and their plumage and bills were used for decorations. In some places anyone that discovers a nest is deemed its owner and is entitled to sell the birds within.[citation needed] In the western world they were first popularised byJohn Gould, who devoted two editions to a detailed monograph of the family.[12] The constellationTucana, containing most of theSmall Magellanic Cloud, is named after the toucan.
The family has been used prominently in advertising. During the 1930s and 1940sGuinness beer advertising featured a toucan, as the black and white appearance of the bird mirrored the stout.[12] A cartoon toucan,Toucan Sam, has been used as the mascot ofFroot Loops breakfast cereal since 1963, and a toucan is the mascot of theBrazilian Social Democracy Party; its party members are calledtucanos for this reason.
Toucans have also been used in popular media. They have been used as the principal characters inToucan Tecs, a 1992 UK television cartoon about two detectives named Zippi and Zac. InDora the Explorer, the character Señor Túcan is a Spanish-speaking toucan who occasionally gives Dora and her friends advice. Tuca, the anthropomorphic title character of the 2019 showTuca & Bertie is a Toucan, and the companion of the song thrush Bertie. In the 2016 Nintendo 3DS gamePokémon Sun and Moon, the Pokémon Toucannon and its previous evolutions were modeled after a Toco Toucan.[21]
^Reynolds, J. (2003). "Handbook of the Birds of the World, Vol. 7. Jacamars to Woodpeckers".Biological Conservation.111 (2):280–281.doi:10.1016/S0006-3207(02)00275-6.
^abcdefgShort, L.L. & Horne, J.F.M. (2017). Toucans (Ramphastidae). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved fromhttp://www.hbw.com/node/52284 on 25 March 2017).
^Remsen, J.V. Jr.; Hyde, Mary Ann; Chapman, Angela (1993). "The Diets of Neotropical Trogons, Motmots, Barbets and Toucans".The Condor.95 (1):178–92.doi:10.2307/1369399.JSTOR1369399.
.jpg)
