Jacobin cuckoo
| Jacobin cuckoo | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
.jpg)
Jacobin cuckoo ( Clamator jacobinus ) in flight |
||||||||||
| Systematics | ||||||||||
|
||||||||||
| Scientific name | ||||||||||
| Clamator jacobinus | ||||||||||
| ( Boddaert , 1783) |
_at_Hyderabad,_AP_W_136.jpg)
The Jacobin cuckoo ( Clamator jacobinus ) is a species from the family of the cuckoo birds, which belongs to the genus of the crested cuckoo ( Clamator ). It is a medium-sized, slender cuckoo that breeds in Africa and Asia and is a pull-through in the Middle East. In parts of its Indian range, it is considered to herald the monsoons because its return coincides with the onset of rain. In large parts of its range, however, the Jacobin cuckoo is a resident bird. There are three subspecies.
Like many species within the cuckoo, the Jacobin cuckoo is an obligatory breeding parasite that does not raise its offspring itself. The brood parasitism of this species has been known for a long time. Jahangir , a ruler of the Mughal empire (1605–1627), already stated that the Jacobin cuckoo used timalia as host birds. After the Indian Koel and the Eurasian cuckoo, the Jacobin cuckoo is historically the third species for which humans recorded it.
features
Nominate form
The nominate form C. j. jacobinus reaches a body length of 34 centimeters, with the tail accounting for an average of around 16 centimeters. The beak has a length of 2.1 centimeters. The males weigh an average of 78 grams during the breeding season, the females are slightly heavier with an average of 90 grams. Overall, the nominate form is the smallest subspecies.
There is no pronounced gender dimorphism . In both males and females of the nominate form, the head from the base of the beak over the eyes to the neck, the hood and the top of the body are shiny black. The otherwise black wings have a striking white mirror on, by the base of the primaries are formed two through nine. The underside of the body is white, the tail is tiered, the black control feathers have white tips.
Young birds are more dull in color than the adult birds. Their plumage varies from a dark brown to a matt black, the feather bonnet is a bit smaller on yours. The wing mirror is a bit smaller and not pure white like in adult birds. The nestlings are naked when they hatch and initially have pink to orange-pink skin. After 48 hours, the skin color is brown-purple. They have a white egg tooth and a black point at the end of the tongue.
The iris is dark brown and pale yellow only in young birds. The easily presented beak is black, in juveniles it is a little more brownish.
In the Oriental there is no species with which the Jacobin cuckoo can be confused. In Africa, the distribution area of the Jacobin cuckoo overlaps with the similar looking cap cuckoo , which also belongs to the crested cuckoo genus. The Jacobin Cuckoo is smaller, has a shorter tail, a white throat and chest.
Special characteristics of the subspecies
The subspecies C. j. pica is slightly larger than the nominate form. The underside of the body is not white, but rather yellowish beige. No visual difference can be seen between the Asian and African populations of this subspecies.
The subspecies C. j. serratus , which occurs in southern Africa, is the largest subspecies. There are two color morphs; One is shiny darling on the top of the body and gray-white to white on the underside of the body. The spring shafts on the throat and chest have dark markings. The flanks are dark gray. The second amorphous color is completely glossy black except for the white wing mirror. There is evidence that this subspecies has specialized in specific host birds and has also adapted to these host birds through egg mimicry.
distribution
The Jacobin Cuckoo is a bird of the Afrotropic and Orientalis . It occurs from sub-Saharan Africa via Iran to Sri Lanka and Burma. Birds of this kind are occasionally observed in Tibet.
The following are the distribution areas of the subspecies:
- C. j. jacobinus is the nominate form . The nominate form occurs in the extreme south of India and Sri Lanka. Migratory birds of this species have already been found in Zimbabwe, Mozambique and Natal. It is the smallest subspecies.
- C. j. pica has a disjoint range with populations in both Africa and Asia. It occurs in Asia in the north of India, in Nepal, in the southeast of Tibet, in Bangladesh as well as in the south and in the center of Burma. Occasionally, individuals can also be observed in Thailand. Another population lives in the region of southeast Iran, Afghanistan, and eastern Pakistan. A large part of the Asian population of this subspecies migrates to Africa in the winter months and crosses the south of the Arabian Peninsula on their migration. In Africa, this subspecies occurs from southern Mauritania to the south of Mali, Burkina Faso, Senegal and Gambia to Ethiopia and Somalia. In the south the distribution area extends to the north of Zambia and Malawi as well as Tanzania. The subspecies overwinters south of the equator.
- C. j. serratus is the subspecies found in the extreme south of Africa. The distribution area is south of the Zambezi and extends to the east of Botswana, Namibia, Zimbabwe and southern Zambia. The subspecies is a migratory bird. They overwinter in Kenya, Eritrea, Ethiopia and Sudan. In the winter months this subspecies can be found in northern Kenya, Eritrea, Ethiopia and Sudan.
habitat
The habitat of the Jacobin cuckoo is dry, loosely existing woodland and grass-thorn-bush steppes. They are also found in gardens and tree plantations, but are absent in dense forests. In West Africa, typical habitats are semi-arid parts of the Sahel, thickets in marshland and savannas with trees and shrubs from the genus of mimosa or acacia . In the interior of Africa, as well as in the east and south, they inhabit grass-thorn-bush steppes, loosely tree-lined areas and agricultural land at altitudes below 1000 meters. In India, they are found in semi-deserts as well as in regions with higher rainfall with deciduous trees. There they can often be found both in village and in urban groves. They occur from the lowlands up to altitudes of 2600 meters, were also encountered during the migration at altitudes of 4270 meters.
Way of life
During the breeding season, the Jacobin cuckoo can only be seen in smaller groups during courtship. They then attract attention through their call duels and their sometimes aggressive chases. Outside of the mating season, they can usually be observed individually during the breeding season.
Food and foraging
_with_a_catterpillar_W_IMG_4009.jpg)
_Photograph_By_Shantanu_Kuveskar.jpg)
Jacobin cuckoos can often be observed when they are looking for food in low bushes, in trees or on the ground, or when they openly shout while sitting on telephone wires, for example. They try to catch flying insects in a fluttering flight.
Their diet consists mainly of caterpillars. Like many cuckoos, they also eat hairy caterpillars, which are spurned by other bird species. Before consuming these prey, they try to remove both the intestinal contents and the hair. They also eat other large insect larvae, termites, beetles, ants, praying mantises, crickets and grasshoppers, snails and occasionally bird eggs. Eating berries and occasionally even green leaves has also been proven.
Reproduction
The Jacobin cuckoo breeding season usually coincides with the rainy season. Accordingly, eggs of this cuckoo species can be found in Ethiopia in the period from March to July and in October. In the Republic of South Africa, on the other hand, eggs are laid between October and March. The laying time of a single female can take up to ten weeks.
Jacobin cuckoos are obligatory brood parasites; when laying their eggs, they display behaviors that are typical for brood parasites. The female observes the nest of the host birds from a hide where possible. The male distracts the host birds and the female lays her egg in their nest within a few seconds. Eggs are usually laid for no more than 10 seconds. Females usually lay two days apart, which is also a characteristic of many brood-parasitic cuckoos. It has not yet been proven that the females remove an egg from the host bird's nest while laying eggs, as is typical with other cuckoos. However, an egg of another bird species was found in the crop of a female ready to lay, which is typically one of the host birds. After laying eggs, the male mates again for the female by offering her food, and mating occurs again.
Due to the large distribution area, Jacobin cuckoo parasitize a very wide range of different host bird species. The proven host bird species in southern Africa include the Graubülbül , palm pigeon , red rein mousebird and brown-winged mousebird . In India there are predominantly species of the genus Turdoides .
The eggs of the Jacobin cuckoos, which have their breeding area in India as well as in the northern African range, show a similarity with the eggs of timalia . They are, however, somewhat larger, of a rounder shape and of a paler blue. The eggs show no resemblance to the eggs of the Bülbüls , which is also an indication that this host bird species has not been parasitized by the Jacobin cuckoo for a long time: the typical defense mechanism - the removal of eggs that differ from the rest of the clutch - has changed in this family not developed yet.
The Jacobin cuckoo nestlings hatch after a breeding season of eleven to twelve days. They hatch earlier than is typical, for example, for African Bülbüls. Up to now it has not been observed that the Jacobin cuckoo nestlings throw other nestlings or eggs out of the nest. Similar to the well-studied jay cuckoo belonging to the same genus, nestlings seem to tolerate the offspring of the parent birds, but they are more assertive. Their nesting siblings are often trampled down or wither away by the precocious Jacobin cuckoos because they do not receive enough food.
The nestlings of the Jacobin cuckoo are initially blind, their eyes only open on the sixth day. As a rule, they are fully feathered on the 15th day of life and usually leave the nest on the 17th day of life, but are then dependent on being fed by the host birds for another 15 to 25 days.
Duration
Jacobin cuckoos are considered a non-threatened species of bird, as their range is large and they are common in parts of the range. Even in semi-arid regions, they are comparatively insensitive to changes in habitat.
This type of cuckoo is common in the dry, tree-lined regions of Africa. In the Republic of South Africa in the south of the distribution area, however, the population fluctuates over the years. The Jacobin cuckoo is rare in Senegal and Gambia, while it is a common bird in Kenya and northern Tanzania at certain times of the year. The Jacobin cuckoo is also a common bird in Ethiopia.
The Jacobin cuckoo is a common breeding bird in Pakistan. It is particularly common around Islamabad . In Nepal, on the other hand, it can only be observed occasionally in summer. In Burma it is only an occasional breeding bird, but it is common in India.
literature
- NB Davies: Cuckoos, Cowbirds and Other Cheats . T & AD Poyser, London 2000, ISBN 0-85661-135-2 .
- 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 .
Web links
Single receipts
- ↑ Khachar, Shivrajkumar: Pied Crested Cuckoo Clamator jacobinus - the harbinger of the monsoon. . In: J. Bombay Nat. Hist. Soc. . 86, No. 3, 1989, pp. 448-449.
- ↑ a b c d e Erhitzøe, Mann, Brammer, Fuller: Cuckoos of the World . P. 270.
- ↑ Davies: Cuckoos, Cowbirds and Other Cheats . P. 3
- ↑ a b c d Erhitzøe, Mann, Brammer, Fuller: Cuckoos of the World . P. 271.
- ↑ a b c d e f g h Erhitzøe, Mann, Brammer, Fuller: Cuckoos of the World . P. 272.
- ↑ Davies: Cuckoos, Cowbirds and Other Cheats . P. 104.
- ↑ Erhitzøe, Mann, Brammer, Fuller: Cuckoos of the World . P. 273.