Blood tailed arassari
| Blood tailed arassari | ||||||||||
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Blood rump arassari ( Aulacorhynchus haematopygus ) |
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| Systematics | ||||||||||
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| Aulacorhynchus haematopygus | ||||||||||
| ( Gould , 1835) |
The blood rump arassari ( Aulacorhynchus haematopygus ) is a species of bird in the toucan family. It occurs exclusively in northern South America. There are two subspecies.
The IUCN classifies the blood-eared arassari as 
(= least concern - not endangered). Exact population figures are not available for this species from the genus Grünarassaris , but it is still considered relatively common.
Appearance
Dimensions
The body length of adult blood rump arassaris is 40 to 45 centimeters. The males of the nominate form have a wing length between 12.9 and 14.4 centimeters, the tail length is between 13.2 and 15.9 centimeters. The beak has a length of 8.1 to 9.4 centimeters. The females are slightly smaller than the males. The only noticeable sexual dimorphism , however, is the significantly smaller beak. In females of the nominate form, the beak length is 6.6 to 7.7 centimeters.
Plumage and beak
Adult blood-rump macaws have deep green plumage. The upper side of the body is usually somewhat darker and has a bronze-colored shimmer, the tail is slightly bluish, the four central tail feathers have red-brown tips. The underside of the body is a little lighter green. The body is bright red, the feathers of the upper tail-ceiling are yellow-greenish at the end. The sides of the chest are pale or dark blue in some individuals. Throat and rein stripes are bluish green. The flanks and the under tail-coverts are yellowish green. The bill is long in relation to body size, the lower bill is slightly curved, the upper bill strongly curved. It tapers at the end. The beak base is white, the rest of the beak deep red to red-brown, only the back of the beak is black. The eyes are dark red to brown. The feet and legs are yellowish green or gray green.
The subspecies Aulacorhynchus haematopygus sexnotatus is slightly smaller than the nominate form and has a reddish beak.
Fledglings have duller plumage compared to the adult blood-eared macaws. Their chin and throat are rather greyish, the color of the trunk, unlike that of the adult birds, is more orange than red. They have no or no completely white beak base.
Possible confusion
The blood-rump macaroni differs from other green macaws by its bright red rump, but it is very often not visible during field observations. The beak is deep red with a white beak base. This distinguishes the blood rump arassari from other green arassari species that are also found in its distribution area. All of these species have a beak that is partially yellow in color. It also differs from these by the green throat that merges into a green colored breast. Sympatric green arassaris have a conspicuously white, gray or blue-gray colored throat. This also applies to the Derby Arassari, which is roughly the same size . The range of the two species overlaps in the east of southern Colombia. Both the blue rein and the leek arassari are slightly smaller than the blood-necked arassari and have a slightly smaller beak.
Distribution area and habitat
The blood rump arassari is a species of bird of the mountain forest regions of the north of South America. Its distribution area extends from the western and central Andes in northern Colombia and Venezuela to southern Colombia and northern Ecuador as well as western Ecuador. The altitude distribution ranges from 300 to 2200 meters in Venezuela and Colombia. In Ecuador it still occurs at altitudes of 2750 meters. Its habitat are tropical and subtropical evergreen forests. The cloud forests of the Andes are also part of its habitat . Occasionally, its habitat extends to the transition to temperate forests. It occurs at slightly lower altitudes than the closely related Laucharassari, but at medium altitudes there is an overlap in the altitude distribution and here it often shares its habitat with this species.
It colonizes secondary forests, thickets and hedges bordering on forests, as well as solitary, fruit-bearing trees near forests. It prefers to stay in the treetops, but is occasionally seen in lower thickets.
Way of life
Blood rump arassaris are observed individually, in pairs and in small groups of up to six individuals. One of the typical interactions within such troops is mutual hunting. This is especially noticeable at the beginning of the breeding season. While foraging for food, it typically zigzags down the tree. The flight seems slower than that of Black Arassaris . It responds to the calls of both green and black arassaris as well as calls from the toucan bearded bird . Aggressive behavior includes strong tail movements, but relatively few vocalizations. Mutual feeding and mutual feathers are also part of courtship behavior.
The breeding season for the nominate form falls between March and May and for the subspecies A. h. sexnotatus in the period January to March. Blood rump macaws breed mainly in old woodpecker holes. The openings are occasionally enlarged by them. Blood-eared macaws in captivity lay up to four white eggs. The breeding season is 16 to 17 days. The laying interval is about a day, and they start hatching before the last egg is laid. Both parent birds are involved in the brood, but the female parent bird has the greater share of the breeding business. Newly hatched nestlings are initially naked and pink. They are only slightly bluish above the eyes that are still closed. Feed both parent birds. The nestlings' diet initially consists of insects, fruits and small birds. The droppings are removed from the nesting holes by the parent birds. The fledglings fledge at around seven weeks of age. After flinging out, the young birds return to the brood cave for a while to rest and the parent birds feed their offspring for a period of several weeks after flinging out. Presumably, the young birds will stay close to the parent birds until the next breeding season.
attitude
Like almost all green arassaris, the blood rump arassi is rarely kept in human care. Between 1982 and 1987 only four zoological gardens worldwide moved a total of 18 young animals.
supporting documents
literature
- Werner Lantermann: Toucans and Arassaris. Filander Verlag, Fürth 2002, ISBN 3-930831-46-5
- Lester L. Short and Jennifer FM Horne: Toucans, Barbets and Honeyguides - Ramphastidae, Capitonidae and Indicatoridae. Oxford University Press, Oxford 2001, ISBN 0-19-854666-1 .
Web links
- BirdLife factsheet on the blood-rump arassari
- Aulacorhynchus haematopygus inthe IUCN Red List of Threatened Species 2013.1. Listed by: BirdLife International, 2012. Retrieved October 23, 2013.