“Great potoo”的意思、由来-开放百科全书

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.

Much like owls, this species is nocturnal. They prey on large insects and small vertebrates, 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]

Description

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)

Distribution and habitat

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.^[3]^[4]

In general the Great Potoo are distributed from humid to semi-humid forested habitats. While this species is widely spreadout geographically, by comparing two subspecies, there is little to no variation in their appearance such as size or plumage.^[2] 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.^[5]^[6]

Behavior

This nocturnal predator is usually seen perched high above the ground while foraging, 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.

Breeding

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.^[7] The nest is a slight depression on a thick tree branch,^[8] 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 {{convert|220|g|oz|abbr=on}}.^[9] 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 rictal bristles. The fledging period must be at least 2 months. After this time span, the offspring do not return to the nest site.^[9]

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.^[10]

Feeding

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.^[11]

Conservation status

Due to its large range, the Great Potoo is seen as a species of least concern, according to the International Union for Conservation of Nature (IUCN). 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.

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, as they do not offer much meat and are hard to locate. In these areas, their feathers are believed to have powers to provide chastity, so they are hunted down for their body parts, which are used to perform ceremonies. It is also believed that parts of their body ward off seduction.^[2]

References

1. ^{{IUCN|id=22689636 |title=Nyctibius grandis |assessor=BirdLife International |assessor-link=BirdLife International |version=2013.2 |year=2012 |accessdate=26 November 2013}}
2. ^¹²{{Cite web|title = Overview - Great Potoo (Nyctibius grandis) - Neotropical Birds|url = http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=222936|website = neotropical.birds.cornell.edu|accessdate = 2015-10-29}}
3. ^{{Cite book|title = Grzmek's Animal Life Encyclopedia|last = Grzmek|first = B.|publisher = Thomson-Gale.|year = 2002|isbn = |location = Farmington Hills, Michigan|editor = 395–400 in M Hutchins|editor2 = J Jackson|editor3 = W Bock Birds I-IV, Vol. 9|editor4 = 2 Edition}}
4. ^{{Cite journal|url = |title = Two New Records of Birds for Southern Mexico|last = J.|first = Luis Rangel-Salazar|date = 1989|journal = Condor|doi = 10.2307/1368168|pmid = |access-date = |last2 = J.|first2 = Humberto Vega-Rivera|pages = 214–215|volume = 91}}
5. ^{{Cite book|title = Observations on Nyctibius grandis in Surinam|last = Haverschmidt|first = F.|publisher = |year = 1948|isbn = |location = |pages = Auk, 65: 30–33.}}
6. ^{{Cite book|title = Observations on the nesting of the great potoo (Nyctibius grandis) in central Venezuela|last = Vanderwerf|first = E.|publisher = The Condor|year = 1989|isbn = |location = |pages = 91: 214–215}}
7. ^E.g. an attended nest at Tiputini Biodiversity Station, Ecuador, in late December 1999 (Cisneros-Heredia 2006).
8. ^E.g. Ceiba sp. (Cisneros-Heredia 2006)
9. ^¹Haverschmidt, F. 1948. Observations on Nyctibius grandis in Surinam. The Auk, 65: 30-33.
10. ^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.
11. ^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.