Guirakuckuck
| Guirakuckuck | ||||||||||||
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Guirakuckuck ( Guira guira ) |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Guira | ||||||||||||
| Lesson , 1830 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Guira guira | ||||||||||||
| ( Gmelin , 1788) |
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The Guira Cuckoo ( Guira guira ) is one of the cuckoo birds and is in the eastern South America is home. It is the only representative of the genus Guira and a common bird in parts of its range. Usually it can be seen in smaller groups. The bird is notorious for its strong body odor.
The Guirakuckuck does not belong to the obligatory brood parasitic species of the cuckoo, but usually raises its young birds in community nests. However, facultative brood parasitism occurs in this species. This leads to conflicts as to how many eggs a respective female lays in the communal nest, which leads to individual eggs being removed from the communal nest and, occasionally, newly hatched nestlings being killed. Guirakuckucke place occasionally as so-called facultative brood parasites and eggs in the nests of birds like the smooth-billed ani , Caracara , chimango caracara , band plantcutter and bronze lapwing .
features
The Guirakuckuck reaches a body length between 36 and 42 centimeters, of which an average of 20 centimeters is on the tail. His body weight averages 140 grams. The wings are short and rounded. The top of the body is dark brown with white dots, the underside of the bait is whitish beige and has very fine black dots on the throat and chest.
The ocher-colored bonnet is sparse, the featherless face is pale yellow to pale greenish. The beak is usually yellow, but can also be orange or salmon-colored in individual individuals. The iris in adult birds is usually yellow or yellowish-white, but individual individuals also have orange irises.
Young birds are similar to adult birds, but their wing feathers still have small white spots at the end. The white band at the end of the tail feathers is narrower. Your iris is still gray.
The flight seems clumsy and slow. Flight phases with flapping wings alternate with short gliding phases.
Distribution area and habitat
The Guirakuckuck occurs in Bolivia , Paraguay , Brazil , Uruguay and Argentina , it is a resident bird in its respective distribution area.
The habitat of the guirakuckucks are savannahs: Accordingly, they occur in the Cerrado , Gran Chaco and Pampas of South America. It also inhabits forest edges, fields and gardens. The guirakuckuck also invades suburbs and parks, as well as orchards, or hangs along streets. It can be observed along the Andes up to an altitude of 1,800 meters. Due to the deforestation of forests in South America, its range has expanded.
behavior
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Guirakuckucks are showy birds that can often be seen sitting on bushes, wire fences, poles, or looking for food on the ground. In the vicinity of farms and cattle ranches, they also become trusting towards humans. They are always associated with smooth-billed anise.
The guirakuckuck can often be observed in small flocks, which outside the breeding season can comprise up to 20 individuals. During the breeding season, the flocks are typically smaller and then usually contain 6 to eight individuals. Not all of these birds are related to one another. Especially at night, they seek to be close to their fellow species and then sit tightly packed in bamboo thickets or leafy trees. Occasionally, guirakuckucks resting together form a circle in which each bird has its front side turned outwards. Mutual preening of feathers is also typical for this species. In the morning, in the evening and after rain showers, the members of a team take sunbaths together. You then sit with your back to the sun, have raised your feathers and let your wings hang down.
food
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Guirakuucks eat beak peas , beetles, praying mantises, ants, flies, swarming termites, locusts, butterflies and their caterpillars, spiders and lobsters. Their food spectrum also includes small amphibians, as well as lizards and bats. They also eat the eggs and nestlings of some other birds. These include the eggs and nestlings of red-axed cowbird , South American tyrant species and house sparrows . They also eat mice and search kitchen rubbish for anything to eat. Prey animals are generally swallowed whole. Termites catch them by building up in the middle of the swarming insects.
The Guirakuckuck mostly looks for food in troops on the ground, occasionally in trees. The peak of foraging falls in the period between 10 a.m. and 1 p.m.
The members of a squad keep a distance of about one meter from one another. On the ground they scare away prey by walking, running and jumping up. Occasionally they also watch the ground from a hide behind a prey and then either jump on the ground or slide down as soon as they discover one.
Reproduction
During the breeding season, guirakuckucks form small flocks that can range from two to 18 individuals. The typical troop size is six to eight individuals. The respective squad defends a territory and lays the eggs in a community nest. NB Davies cites the guirae chuckoo as an indication that the cuckoo family, of which 57 of 140 species are obligate parasites, has a particular tendency to develop brood parasitism. From his point of view, the community-nesting guirakuucks represent a stage of development on the development path to such behavior.
Breeding season
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The guirakucuck's breeding season varies within its large distribution area. The guirakuckuck breeds in central Brazil during the rainy season, which lasts from July to March. September and October are the main breeding season during this period. In the region around Rio de Janeiro, however, the breeding season extends from April to February. In Uruguay, on the other hand, breeding birds are observed between October and December.
During their long breeding season they brood several times. In some areas, up to five attempts at nesting have been observed within one breeding season. After a failed nesting attempt, it takes an average of 35 days for a troop to start again with their community nest. On the other hand, there is an average of 66 days to the next attempt at breeding if a clutch has been successfully raised.
Mating and nest
The mating of guira-chucks usually takes place on the ground. The mating is preceded by a courtship of the male, in which this dances with open wings around the female sitting on the ground.
The large shell nest consists of branches, roots and blades of grass. It is laid out with green leaves, straw and flowers. The outer diameter is between 15 and 40 centimeters, the inner between 14 and 20 centimeters. It is planted in solitary trees or large cacti. In central Brazil, the guirakuckuck prefers to use the introduced araucarias as a nesting tree. Basically, the nest is built as high as possible and is between 3 and 12 meters above the ground. Old nests are often used again after they have been supplemented with nesting material. Occasionally, other birds' nests are also used.
Eggs
Typically up to seven females lay in a community nest, the number of eggs is higher the more females belong to a troop. The clutch size is between 4 and 20 eggs. In one case, 30 eggs were counted in a nest. The eggs are large in relation to the guirakuckoo's body weight. The laying interval of an individual female is two days, only in exceptional cases is she able to lay an egg the next day.
It happens that other eggs are thrown out of the nest or that they are so close to the edge of the nest that they are not incubated. On average, around half of the eggs in these joint clutches are lost. This loss of eggs is also brought about by the birds in a targeted manner: adult guiraku chucks take individual eggs in their beak and throw them directly out of the nest or take an egg in their beak, move away a few meters from the nest and drop it there. This behavior can be observed especially at the beginning of the egg-laying, but can also occur when the eggs are already incubated. There is evidence that this behavior occurs mainly in females who have not yet begun to lay eggs. Basically, a female's eggs vary so much in size, shape, color and pattern from one another that she is unable to identify her own eggs within a clutch.
The incubation period is 9 to 16 days. Males are occasionally involved in the incubation of the eggs.
Fledglings
Nestlings are occasionally removed from the nest by members of the squad or even killed there. This usually happens in the first few days after the nestlings have hatched. This infanticide leads to the fact that the nest is occasionally abandoned by the troop. According to individual studies, the percentage of nests in which there is a full or partial infanticide is 69 percent. However, it is also typical that an adult bird of the flock is always near the nest when nestlings have hatched there.
The nestlings generally all hatch within a very short time - in a large number of examined clutches, the nestlings hatched from all the incubated eggs within 24 hours. The longest observed period of time until the nestlings hatched in a nest was four days. The nestling period lasts between 12 and 18 days on average. On the second day of life, the eyes are open, the color of the iris is brown. At three to four days they begin to stir in the nest and beg with loud cries when an adult bird appears with food on the edge of the nest. From the seventh day of life, the young birds are already able to leave the nest if it is disturbed. On the tenth day of their life, they already have plumage that is similar to that of adult birds. They are then more and more often outside the nest and hide in the foliage when there is a disturbance in the nest. They climb around on the branches with the help of their beak and wings. Fledglings of the guirakuckucks that have fledged are fed by the adults outside the nest for at least three weeks. They reached the height of the adult birds at the age of four weeks.
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Most or all of the birds in the flock are involved in feeding the nestlings. The degree of participation varies, however, between the individual squad members. The adult birds mostly carry insects to the nest. In addition, the nestlings are also offered frogs, toads, lizards, snakes, birds, nestlings of other species and mammals. These animals rarely exceed a size of more than six centimeters. The nestlings swallow these prey whole.
Causes of mortality and exposure
Guira cuckoos are very cold-sensitive birds. It happens again and again that birds of this species get hypothermic and die on cold nights.
No population size estimates are available, but the IUCN does not assume any risk due to the large distribution area and the frequency of the species.
literature
- Johannes Erhitzøe, Clive F. Mann, Frederik P. Brammer, Richard A. Fuller: Cuckoos of the World . Christopher Helm, London 2012, ISBN 978-0-7136-6034-0 .
- Colin Harrison & Alan Greensmith: Birds. Dorling Kindersly Limited, London 1993, 2000, ISBN 3-8310-0785-3
Web links
- Videos, photos and sound recordings of Guira guira in the Internet Bird Collection
Single receipts
- ↑ www.itis.gov - ITIS Standard Report: Guira guira
- ↑ a b c d Erhitzøe, Mann, Brammer, Fuller: Cuckoos of the World . P. 101.
- ↑ a b c d e f g h i j k Erhitzøe, Mann, Brammer, Fuller: Cuckoos of the World . P. 102.
- ↑ a b c d e Erhitzøe, Mann, Brammer, Fuller: Cuckoos of the World . P. 103.
- ↑ NB Davies: Cuckoos, Cowbirds and Other Cheats . T & AD Poyser, London 2000, ISBN 0-85661-135-2 . P. 246
- ↑ ZOO BASEL - Animals - Profile Guirakuckuck
- ↑ Guira guira in the endangered Red List species the IUCN 2012. Posted by: BirdLife International, 2012. Accessed November 13, 2012th