Great potoo

Great potoo
in the Pantanal, Brazil
 Birdsong 
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
(unranked): Cypselomorphae
Order: Caprimulgiformes
Family: Nyctibiidae
Genus: Nyctibius
Species: N. grandis
Binomial name
Nyctibius grandis
(Gmelin, 1789)

The Great Potoo (Nyctibius grandis) is a near passerine bird, both the largest potoo species and the largest member of the order Caprimulgiformes (nightjars and allies). They are also one of seven species in one genus, Nyctibius, located in tropical America.

Similar to the owl, this species is also nocturnal. However they prey on eating insects and occasionally bats, which they capture in sallies from high perches.

Possibly its most well known characteristic is its unique moaning growl that the Great Potoo vocalizes throughout the night, creating an unsettling atmosphere in the Neotropics with its nocturnal sounds.[2]

Physiology

Appearance

The Great Potoo has a large head in relation to its body.The eyes are also very large with a brown to yellow iris and has a short but broad beak. Their wings are elliptical in shape and with an elongated tail. The feather colors vary with white, gray, black, and burgundy. The tail colors match with that of the rest of the body with the exception of white bars that can be seen going across the tail laterally. (see references below)

Diet

Their prey consists mostly of large flying insects, especially large beetles, katydids and Orthoptera (including crickets and grasshoppers). Bats are taken occasionally as well. The Great Potoo takes advantage of the night and its natural camouflage by sitting on an exposed perch to wait until some prey flies by, at which point it darts out towards the prey and returns to the branch with it. Very often birds of this species will use the same hunting perch nightly.[3]

Geography and Range

They range from southern Mexico through northeastern Guatemala and through most of Central America down through South America as far as Bolivia and southeastern Brazil.[4][5]

In general the Great Potoo are distributed from humid to semi-humid forested habitats. While this specie is widely spread out geographically, by comparing two subspecies, there is little to no variation in their appearance such as size or plumage.[2]

Geographic range of the Great Potoo

Habitat

The Great Potoo is found mostly in dense lowland forest, forest edges and clearings. It may also range into foothills (up to about 1,500 m elevation), second-growth, open woodlands (including plantations) and is sometimes seen around meadows, but they always require trees-etc., for their camouflaged imitative perch.

In the day they are normally found perching or nesting usually higher than 12 meters above ground level within big trees. The branches they choose to perch usually are nearly 20 to 30 centimeters in diameter. At night time, they may go to lower perches like 1.5 meters above the ground, from which they hunt.[6][7]

Behavior

This nocturnal predator is usually seen perched high above the ground while forgaging, sallying out when prey is spotted. After the pounce, the potoo almost always returns to its previous perch. Normally, during the day it perches upright on a tree stump, and is overlooked because it resembles part of the stump; this is a camouflage, not just by coloration, but a camouflage by the setting. The Great Potoo can be located at night by the reflection of light from its eyes as it sits vertical on a post, roost, or angled-tree trunk.

Reproduction

Breeding has been recorded as typically February to August, but depending on the portion of this bird's range breeding birds can be met with almost year-round.[8] The nest is a slight depression on a thick tree branch,[9] at least 10 m (33 ft) above ground, with a single white (slightly spotted) egg measuring about 5.2 x 3.8 cm (2 x 1.8 inches). Few details are known of the brooding behavior, but about a month elapses before the offspring is seen alone at the nest. A chick of a few days old weighed 220 g (7.8 oz).[10] After about 5 weeks the nestling is a two-thirds version of the adult, but with a lighter build, paler plumage, shorter tail, and smaller bill with less rectal bristles. The fledging period must be at least 2 months. After this time span, the offspring do not return to the nest site.[10]

Although the adult potoo likely has few natural predators, predation of eggs, nestlings and fledging is apparently not uncommon. Adults stay near the nest throughout the day and rely upon camouflage to protect their offspring. Predators of great potoo nests in Costa Rica have included monkeys such as mantled howlers, Geoffroy's spider monkeys and white-headed capuchins as well as tayras and collared forest falcons.[11]

Conservation Status

The Great Potoo is seen as a species of least concern, according to the International Union for Conservation of Nature. This species population is not growing, however it has a large range and population. So their decreasing population is not of major concern for conservationists. The Great Potoo is normally described as "uncommon", but occurs frequently in areas of less disturbed forests and is often found to be rare along the edges of its range. The clearing of forest is the only conservation threat known to this bird. Due to its large range, it is considered a species of least concern by the IUCN.

Effects of Humans on the Great Potoo Population

The local people in the rural area of Brazil sometimes use Potoo as a minor food source. This is because they do not offer much meat and are hard to locate. In the rural parts of Brazil the Potoo feathers are believed to have powers to provide chastity. Therefore the Great Potoo are hunted down for their body parts in order to be used in these rural areas where they perform ceremonies. It is also believed that parts of their body ward off seduction.[2]

References

  1. ↑ BirdLife International (2012). "Nyctibius grandis". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
  2. 1 2 3 "Overview - Great Potoo (Nyctibius grandis) - Neotropical Birds". neotropical.birds.cornell.edu. Retrieved 2015-10-29.
  3. ↑ Cohn-Haft, M. 1999. Family Nyctibiidae (Potoos). Pages 288-301 in J. del Hoyo, A. Elliott, and J. Sargatal (editors), 'Handbook of the birds of the world. Volume 5. Barn-owls to Hummingbirds'. Lynx Edicions, Barcelona, Spain.
  4. ↑ Grzmek, B. (2002). 395–400 in M Hutchins; J Jackson; W Bock Birds I-IV, Vol. 9; 2 Edition, eds. Grzmek's Animal Life Encyclopedia. Farmington Hills, Michigan: Thomson-Gale.
  5. ↑ J., Luis Rangel-Salazar; J., Humberto Vega-Rivera (1989). "Two New Records of Birds for Southern Mexico". Condor. 91: 214–215. doi:10.2307/1368168.
  6. ↑ Haverschmidt, F. (1948). Observations on Nyctibius grandis in Surinam. pp. Auk, 65: 30–33.
  7. ↑ Vanderwerf, E. (1989). Observations on the nesting of the great potoo (Nyctibius grandis) in central Venezuela. The Condor. pp. 91: 214–215.
  8. ↑ E.g. an attended nest at Tiputini Biodiversity Station, Ecuador, in late December 1999 (Cisneros-Heredia 2006).
  9. ↑ E.g. Ceiba sp. (Cisneros-Heredia 2006)
  10. 1 2 Haverschmidt, F. 1948. Observations on Nyctibius grandis in Surinam. The Auk, 65: 30-33.
  11. ↑ Young, B., J. Zook. 1999. Nesting of four poorly-known bird species on the Caribbean slope of Costa Rica. The Wilson Bulletin, 111: 124-128.

External links

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