Yellow-throated toucan

The yellow-throated toucan (Ramphastos ambiguus) is a Near Threatened species of bird in the family Ramphastidae, the toucans, toucanets, and aracaris. It is found from Honduras south into northern South America and beyond to Peru.[2][1]

Yellow-throated toucan
R. a. swainsonii in Costa Rica
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Class: Aves
Order: Piciformes
Family: Ramphastidae
Genus: Ramphastos
Species:
R. ambiguus
Binomial name
Ramphastos ambiguus
Swainson, 1823
Subspecies

See text

Taxonomy and systematics

Three subspecies of yellow-throated toucan are recognized:[2][3][4]

  • "Chestnut-mandibled" toucan, R. a. swainsonii - (Gould, 1833)
  • "Black-mandibled" toucan (in part), the nominate R. a. ambiguus - Swainson, 1823
  • "Black-mandibled" toucan (in part), R. a. abbreviatus - Cabanis, 1862

All three subspecies were originally described as separate species. R. a. abbreviatus was relatively early reassigned as a subspecies of R. a. ambiguus. Subspecies R. a. swainsonii differs from ambiguus by 1.35% in mitochondrial DNA which led to its treatment as a species by major taxonomies until about 2010.[5][6][7][8]

Ramphastos ambiguus at the Bronx Zoo

Description

The yellow-throated toucan is 47 to 61 cm (19 to 24 in) long and weighs 584 to 746 g (1.3 to 1.6 lb). The three subspecies differ little in their dimensions, though females' bills are shorter than males' in all three. Bill lengths vary between 15.1 and 19.8 cm (5.9 and 7.8 in) in males and 12.9 and 16.0 cm (5.1 and 6.3 in) in females. Other measurements differ little by sex. Their wing chord is 20.4 to 24.8 cm (8.0 to 9.8 in), their tail length is 14.0 to 16.2 cm (5.5 to 6.4 in), and their tarsus is 4.7 to 5.5 cm (1.9 to 2.2 in) long.[9][8]

The yellow-throated toucan's subspecies have essentially the same plumage. They are mostly black, with a maroon tint to the hindneck and upper back and white uppertail coverts. Their face, throat, and upper breast are bright yellow with white and crimson bands below the breast. Their vent and undertail coverts are bright red. The bare skin around their eye does differ: sky blue in the nominate R. a. ambiguus, yellow green in R. a. abbreviatus, and varying between yellow and bright green in R. a. swainsonii. The three subspecies' bills differ as well. All have a mostly yellow maxilla with a greenish yellow stripe on the culmen and a thin black line at the base. The nominate and R. a. abbreviatus have black mandibles; R. a. swainsonii' is maroon to reddish chestnut brown.[9][8]

Distribution and habitat

The subspecies of yellow-throated toucan are found thus:[8]

  • R. a. swainsonii, from southeastern Honduras through Nicaragua, Costa Rica, Panama, and western Colombia to southwestern Ecuador
  • R. a. ambiguus, from southwestern Colombia on the eastern slope of the Andes to south-central Peru
  • R. a. abbreviatus, northeastern Colombia and northwestern and northern Venezuela

The "chestnut mandibled" R. a. swainsonii primarily inhabits lowland evergreen primary forest and also occurs in gallery forest, older secondary forest, and well-treed parks and gardens. It shuns dry forest and large open areas but can be found in plantations with fruiting trees that border forest. The two "black-mandibled" subspecies are usually found in the interior of humid primary montane forest but also occur at its edges and clearings and in older secondary forest.[8] In Ecuador the "chestnut-mandibled" is found from sea level to 1,000 m (3,300 ft), in Colombia below 2,000 m (6,600 ft), and in Costa Rica to 1,200 m (3,900 ft). The "black-mandibled" occurs between 1,000 and 1,600 m (3,300 and 5,200 ft) in Ecuador and up to 2,500 m (8,200 ft) in Colombia.[10][11][12]

Behavior

Movement

As far as is known the yellow-throated toucan is a year-round resident throughout its range.[8]

Feeding

Most of the data on the yellow-throated toucan's diet and foraging behavior are from studies of the wide-ranging R. a. swainsonii. It is primarily a fruit eater, with small amounts of animal matter such as insects and other arthropods, small lizards, and the eggs and young of other birds. Most of the animal matter is apparently fed to nestlings. The species forages mainly in the forest canopy, singly, in pairs, or in small groups, but also retrieves fallen fruit from the ground. They take fruit by hopping from branch to branch and may hang upside down to reach it. Though the species is not territorial, individuals often defend a single fruiting tree.[9][8]

Breeding

The yellow-throated toucan's breeding season varies latitudinally, from March to June in Costa Rica, January to July in Panama and Colombia, and between December and May in Ecuador. Males allopreen and courtship-feed females. The species nests in tree cavities formed by rot; they may enlarge it but cannot truly excavate. The cavity is typically between 9 and 30 m (30 and 98 ft) above the ground. The clutch size is thought to be two or three eggs. The incubation period and time to fledging are not known. Both parents defend the nest and care for young.[9][8]

Vocal and non-vocal sounds

The yellow-throated toucan's primary vocalization is "a series of loud, far-carrying yelps." The call is somewhat variable in tempo and the number of notes. It has been transcribed as "Díos te dé te dé", which translates from Spanish as "God give you". The species calls year round, usually from the tops of trees, and especially near dawn and dusk. It also "grunts, croaks, and rattles loudly in aggressive displays." In flight its wings rustle due to notches in the two outer primaries.[9][8]

Status

The IUCN has assessed the yellow-throated toucan as Near Threatened. It has a very large range, but its population size is not known and is believed to be decreasing. The major threat is continuing conversion of its forest habitat to agriculture and ranching; hunting is also a threat.[1] "Yellow-throated Toucan is able to tolerate some human disturbance and forest alteration, but is nonetheless affected greatly by habitat loss."[8]

References
  1. BirdLife International (2016). "Yellow-throated Toucan Ramphastos ambiguus". IUCN Red List of Threatened Species. 2016: e.T22727999A94967701. doi:10.2305/IUCN.UK.2016-3.RLTS.T22727999A94967701.en. Retrieved 5 January 2023.
  2. Gill, F.; Donsker, D.; Rasmussen, P., eds. (August 2022). "Jacamars, puffbirds, barbets, toucans, honeyguides". IOC World Bird List. v 12.2. Retrieved December 15, 2022.
  3. Clements, J. F., T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, S. M. Billerman, B. L. Sullivan, and C. L. Wood. 2022. The eBird/Clements checklist of birds of the world: v2022. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ retrieved November 10, 2022
  4. HBW and BirdLife International (2022) Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 7. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v7_Dec22.zip retrieved December 13, 2022
  5. R. Terry Chesser, Richard C. Banks, F. Keith Barker, Carla Cicero, Jon L. Dunn, Andrew W. Kratter, Irby J. Lovette, Pamela C. Rasmussen, J. V. Remsen, Jr., James D. Rising, Douglas F. Stotz, and Kevin Winker. "Fifty-second supplement to the American Ornithologists' Union Check-list of North American Birds". The Auk 2011, vol. 128:600-613 retrieved January 5, 2023
  6. Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, A. Jaramillo, D. F. Lane, J. F. Pacheco, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 24 July 2022. A classification of the bird species of South America. American Ornithological Society. https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm retrieved July 24, 2022
  7. "Ramphastos swainsonii - Avibase". avibase.bsc-eoc.org. Retrieved January 5, 2023.
  8. Rice, A. A., J. D. Weckstein, and J. Engel (2020). Yellow-throated Toucan (Ramphastos ambiguus), version 1.0. In Birds of the World (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.bkmtou1.01 retrieved January 5, 2023
  9. Short, Lester L.; Horne, Jennifer (2001). Toucans, Barbets & Honeyguides. Oxford University Press. ISBN 0-19-854666-1.
  10. Ridgely, Robert S.; Greenfield, Paul J. (2001). The Birds of Ecuador: Field Guide. Vol. II. Ithaca: Cornell University Press. p. 330. ISBN 978-0-8014-8721-7.
  11. Garrigues, Richard; Dean, Robert (2007). The Birds of Costa Rica. Ithaca: Zona Tropical/Comstock/Cornell University Press. p. 154. ISBN 978-0-8014-7373-9.
  12. McMullan, Miles; Donegan, Thomas M.; Quevedo, Alonso (2010). Field Guide to the Birds of Colombia. Bogotá: ProAves. p. 107. ISBN 978-0-9827615-0-252995.{{cite book}}: CS1 maint: ignored ISBN errors (link)
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