White-throated toucan

The white-throated toucan (Ramphastos tucanus) is a near-passerine bird in the family Ramphastidae found in South America throughout the Amazon Basin including the adjacent Tocantins and Araguaia River drainage. It prefers tropical humid forest, but also occurs in woodland and locally in riverine forest within cerrado. This bird can be found in Bolivia in the Beni Departement, notably in the city of Riberalta and in the close by Aquicuana Reserve.

White-throated toucan
Ramphastos t. tucanus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Piciformes
Family: Ramphastidae
Genus: Ramphastos
Species:
R. tucanus
Binomial name
Ramphastos tucanus
Subspecies

See text

Synonyms
  • Ramphastos Tucanus
At first this may resemble a Cuvier's toucan, R. t. cuvieri, but a closer look reveals a brownish patch on the upper part of the mandible, identifying it as a tucanus-cuvieri intergrade.
Red-billed toucan
Ramphastos t. tucanus
Red-billed toucan in captivity

Taxonomy and systematics

The white-throated toucan was formerly considered to be three separate species. The red-billed toucan and Cuvier's toucan, which differ principally in the bill colour, interbreed freely wherever they meet and therefore now merit only subspecies status. Some authorities consider the Inca toucan to represent a stable hybrid population between the other two subspecies and do not recognize it as a separate subspecies.

Subspecies

Three subspecies are recognized:[2]

  • Red-billed toucan (R. t. tucanus) - Linnaeus, 1758: Found in south-eastern Venezuela, the Guianas and northern Brazil
  • Cuvier's toucan (R. t. cuvieri) - Wagler, 1827: Originally described as a separate species. Found in upper Amazonia from western Venezuela to northern Bolivia
  • Inca toucan (R. t. inca) - Gould, 1846: Originally described as a separate species. Found in northern and central Bolivia

Description

Like other toucans, the white-throated toucan is brightly marked and has a huge bill. It has a total length of 50–61 cm (19.5–24 in).[3] Body weight is somewhat variable, ranging in adult birds from 425 to 830 g (0.937 to 1.830 lb). The male averages slightly larger, at a mass of 642 g (1.415 lb), while the female averages 580 g (1.28 lb). Among standard measurements, the wing chord is 20.4 to 26.5 cm (8.0 to 10.4 in), the bill is 12.2 to 22 cm (4.8 to 8.7 in), the tail is 13.3 to 16.8 cm (5.2 to 6.6 in), and the tarsus is 4.5 to 5.6 cm (1.8 to 2.2 in).[4] The only species of toucan that surpasses the white-throated in size is the toco toucan.

It has black plumage with a white throat and breast bordered below with a narrow red line. The rump is bright yellow and the crissum (the area around the cloaca) is red. The bare skin around the eye is blue. The bill has a yellow tip, upper ridge and base of the upper mandible, and the base of the lower mandible is blue. The rest of the bill is mainly black in R. t. cuvieri and mainly reddish-brown in R. t. tucanus, with intergrades showing a mixed coloration. Males are larger and longer-billed than females, but otherwise the sexes are alike.

Juveniles are noticeably shorter-billed, more sooty-black, and have duller plumage.

The white-throated toucan of the race cuvieri is virtually identical to the related channel-billed toucan of the race culminatus, but the latter is smaller and has a proportionally shorter bill with a more strongly keeled culmen. The call is often the best distinction between the species. White-throated has a yelping eeoo, hue hue, whereas channel-billed has a croaking song.

Behaviour

Small flocks or more commonly pairs of birds move through the forest with a heavy, rather weak, undulating flight, rarely flying more than 100 m (330 ft) at a time. This species is primarily an arboreal fruit-eater, but will also take insects, lizards, eggs, and small birds.

Breeding

The 2–4 white eggs are laid in an unlined cavity high in a decayed section of a living tree, or in an old woodpecker nest in a dead tree.

Both sexes incubate the eggs for at 14–15 days, and the toucan chicks remain in the nest after hatching. They are blind and naked at birth, with short bills, and have specialised pads on their heels to protect them from the rough floor of the nest. They are fed by both parents, and fledge after about 6 weeks. The parents continue feeding the juveniles for several weeks after they have left the nest.

Aviculture

White-throated toucans (specifically the red billed subspecies) are sometimes kept as pets. However, like the chestnut-mandibled toucan they are considered to be noisy, when compared to other frequently kept toucans such as the keel-billed toucan and toco toucan. It is illegal to take toucans or any other protected wild bird species from their natural habitat.

References
  • Steven L. Hilty (2003). Birds of Venezuela. Christopher Helm Publishers, Incorporated. ISBN 978-0-7136-6418-8.
  1. BirdLife International (2012). "Ramphastos tucanus". IUCN Red List of Threatened Species. 2012. Retrieved 26 November 2013.CS1 maint: ref=harv (link)
  2. "IOC World Bird List 6.4". IOC World Bird List Datasets. doi:10.14344/ioc.ml.6.4.
  4. Lester Short; Jennifer F. M. Horne (2001). Toucans, Barbets, and Honeyguides: Ramphastidae, Capitonidae and Indicatoridae. Oxford University Press. ISBN 978-0-19-854666-5.

Bibliography
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