Giant ani
| Giant ani | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
.jpg)
Giant ani ( Crotophaga major ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Crotophaga major | ||||||||||||
| Gmelin , 1788 |
The giant ani ( Crotophaga major ) is the largest member of the genus Crotophaga within the cuckoo family (Cuculidae). The black, conspicuously long-tailed bird is found mainly in the damp lowlands of northern and central South America. He looks for his insect prey in family groups of up to a dozen birds on the ground or in the branches of the trees. Giant anise are not brood parasites , but primarily community breeders . Usually several females lay their eggs in a jointly built nest and raise the young together with the other group members. The monotypic species is common in places and its population is not endangered.
Appearance
Giant anise are black, strikingly long-tailed birds. With a total length of 46 centimeters, they almost reach the size of the local magpie . The tail, which widens towards the tip, makes up a little more than half of the total length. Another characteristic is the mighty, arched, laterally compressed beak at the upper beak. The entire plumage is black. The neck area, chest and back often have a bluish sheen, the ends of the feathers shimmer green. On the wings, this gloss changes into a bluish tinge, the tail shines more purple. The beak is black; the upper beak has a distinct hump from about the middle of the beak. Two parallel notches run at the base of this elevation and a little deeper from the nostrils to the tip of the beak. The iris of the eyes is white with a light greenish tinge, the legs are black. Like other aniseed, giant aniseed gives off an unpleasant, pungent-sharp odor, especially in stressful situations.
The sexes do not differ in color. Males appear to be slightly larger and, at an average of 170 grams, also a little heavier than the females. Immature giant anise is largely similar to adult anise in terms of plumage, but the beak is not yet developed, the iris is dark brown and the tail is narrower towards the end.
Giant anise should be unmistakable in its area of distribution due to its size. The smooth-beaked ani, which is very similarly colored and sympatric in large areas, is almost a third smaller and a significantly less powerful flier. The upper beak hump is rounded, while the giant ani rises diagonally.
voice
Giant anise are very noticeable acoustically throughout the year. Your vocal repertoire is very diverse. Frequently guttural, dull, gurgling series of calls can be heard, reminding of the bubbling of boiling water. Correspondingly, the Riesenani is called Hervidor in the Orinoco region , which is derived from the Spanish verb verbi = cook . In addition, a series of croaking, screeching, but also shrill calls and whistles can be heard.
distribution and habitat
The range of the species extends from the channel region of Panama over the whole of northern and central South America to the south, mainly east of the Andes chain, to Bolivia , Paraguay and northern Argentina . Only in the north and in the central area of the area does the occurrence extend to the Pacific coast. The islands off the North American coast, in particular Trinidad, are also populated . The main points of distribution are in the hot and humid lowlands of North and Central South America, especially the river systems of the Orinoco, the Río Magdalena and the Amazon . The settlement densities decrease significantly to the south and south of the Tropic of Capricorn the Riesenani is rare and regionally an exception.
The breeding areas are mostly in tropical lowland areas below 500 meters. Outside the breeding season, wandering groups or migrating young birds can be found at heights of over 2000 meters.
Giant anise are resident birds in most of their range. Outside the breeding season, they can wander around rather small-scale. The southernmost populations of Paraguay and northern Argentina make short seasonal migrations.
Giant anise prefer moist habitats. They breed in woods that accompany rivers along tropical rivers or oxbow lakes, in mangrove swamps on the coast, on the edges of dense, moist, often temporarily flooded forests, or in other moist, tree-lined landscapes. In drier areas, the species only penetrates along the gallery forests , and giant anise only colonize the interior of tropical forests at the edges of the rivers.
Food and subsistence
Giant anise are primarily insectivores. The main prey animals are various grasshoppers , catching horrors , cicadas , caterpillars and beetles, and occasionally dragonflies and other invertebrates. Less often they prey on small mammals, birds or fish. Fruits and seeds play a rather subordinate role. Like other aniseed, giant aniseed also search grazing animals, especially cattle, for ticks. The generic name Crotophaga means tick eater .
The food is obtained on the ground and in all trunk regions up to the top of very tall trees, primarily by picking up and reading. When looking for food, giant anise are always kept with other members of their own species. Occasionally they follow trains of driver ants or groups of squirrel monkeys , which in turn scare away insects.
Systematics
The species belongs to the small genus Crotophaga , to which the Riefenschnabelani and the Glattschnabelani also belong. Sister genus is the monotypical genus Guira , which is also restricted to South America . The species is monotypical, no subspecies are described.
Behavior and Breeding Biology
Giant anise are highly socially living birds that live together in groups of 4 to about 10 individuals. These groups consist of several monogamous couples, the most common of which are three. Unmated individual birds, mostly females, can belong to a group. Single pairs apparently do not brood. Joint clutches of groups with more than three pairs are often abandoned before breeding.
The breeding season is strongly dependent on the geographical location: in Trinidad it is between August and November, in Guyana it extends from May to December. The breeding seasons of the more southern populations are not known.
The nest is an extensive structure made of twigs and tendrils and camouflaged on the outside with green twigs and leaves. It is often erected on branches hanging over the water at a height of 3–5 meters. All group members are involved in its construction, and it takes between 3 and days to complete. The size of the clutch depends on the number of females involved and varies between 2 and 3 and over 10. The green-blue, whitish-dotted eggs have an average size of 45 × 38 millimeters; they are therefore strikingly large in relation to the size of the birds. They are incubated by some group members between 11 and 14 days; all group members take part in raising youngsters. After hatching, giant anise vigorously defend their brood against nest predators, mainly various tree-climbing snakes, monkeys and birds of prey. The nestlings leave the nest after just 8-10 days, but are looked after by the adults for a few more weeks, first as branchlings and then as fledgling young birds. At around 5 days old, chicks are able to drop into the water in case of danger, swim to the bank and get back to the nest from there. Nestlings also defend themselves by explosively and purposefully emptying the cesspool . However, the boy mortality rate is high and rarely do more than half of the chicks fledge. No information is available about the length of time the young birds remain in the family group or about their dismigration.
Duration
The species has a very large range. At least in its core zones, it appears to be relatively common. Stock figures are not available. There are no known decreases in the population or substantial threats, which is why the population is currently assessed as safe.
literature
- Francisco Erize, Jorge R. Rodriguez Mata, Maurice Rumboll: Birds of South America. Non Passerines: Rheas to Woodpeckers. Princeton Illustrated Checklists. Princeton University Press, Princeton / Oxford 2006, ISBN 0-691-12688-7 , pp. 240-241.
- Robert B. Payne: The Cuckoos . (Bird Families of the World No. 15). Oxford University Press, 2005, ISBN 0-19-850213-3 : Plate 1, pp. 6 and 172-174.
Web links
- xeno-canto: sound recordings - Greater Ani ( Crotophaga major )
- Crotophaga major inthe IUCN 2013 Red List of Threatened Species . Listed by: BirdLife International, 2012. Retrieved February 2, 2014.
Individual evidence
- ↑ Robert. B. Payne: The Cuckoos. 2005, p. 172.
- ↑ Robert. B. Payne: The Cuckoos. 2005, p. 173.
- ↑ Robert. B. Payne: The Cuckoos. 2005, p. 173.
- ↑ Robert. B. Payne: The Cuckoos. 2005, p. 173.
- ↑ Robert. B. Payne: The Cuckoos. 2005, p. 172.
- ↑ Michael D. Sorenson, Robert B. Payne: A molecular genetic analysis of cuckoo phylogeny. In: Robert. B. Payne: The Cuckoos. 2005, pp. 83 and 84
- ↑ Christina Riehl, Laura Jara: Natural History and Reproductive Biology of the Communally Breeding Greater Ani (Crotophaga major) at Gatún Lake, Panama. In: The Wilson Journal of Ornithology. 121 (4), 2009, pp. 679-687.
- ↑ Robert. B. Payne: The Cuckoos. 2005, p. 174.
- ↑ Christina Riehl, Laura Jara: Natural History and Reproductive Biology of the Communally Breeding Greater Ani (Crotophaga major) at Gatún Lake, Panama. In: The Wilson Journal of Ornithology. 121 (4), 2009, pp. 679-687, here p. 686.
- ↑ data sheet BirdLife international pdf engl.