Red-tailed cuckoo
| Red-tailed cuckoo | ||||||||||
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Red-tailed cuckoo ( Chrysococcyx basalis ) |
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| Chrysococcyx basalis | ||||||||||
| ( Horsefield , 1821) |
The red-tailed cuckoo ( Chrysococcyx basalis ) is a species of cuckoo that occurs in the Oriental and Australis and is one of the smallest species within the cuckoo family. Like all species from the genus of the real gold cuckoo , it belongs to the obligatory brood parasites .
There are no population size estimates. Due to the size of the distribution area and the frequency of the species, the IUCN does not assume any threat.
features
The red-tailed cuckoo is only slightly sexually dimorphic . In both sexes, the plumage is shiny brown-green on top with white feather tips. The head plumage is brownish, with a white supercilium . The breast plumage is white with black to brown sparrows . The reddish to reddish brown colored tail feathers give it its name. The iris is red to dark brown in the males, the orbital ring is gray to dark gray-brown. In the females, however, the iris is brown to pale blue. The beak is gray-black to black in the male, dark brown to black in the female. The cuckoo is about 16 cm tall. The males weigh an average of 22 grams, the females are slightly heavier and weigh 24.3 grams.
Young birds are similar to the adult ones, but they are more dull and gray-brown on the top of the head and in the neck. The white supercillum is still missing or is only hinted at. Usually they also lack the sparrowing on the underside of the body.
The male's calls are a series of tseeeuw whistles that drop in pitch.
It can be confused with the bronze cuckoo , a cuckoo belonging to the same genus as the red-tailed cuckoo. However, this is a bit larger and lacks the striking supercilium.
Distribution area and habitat
The red-tailed cuckoo can be found all year round in Australia , while it only winters in Java , Borneo , Sulawesi and New Guinea . Another breeding area that is only visited in summer is Tasmania .
In Australia, the main area of distribution is in the southwest and southeast of the continent. However, there is evidence of breeding from all regions of Australia. In the north of Australia there are resident birds of this species, but it is most frequently observed there when red-tailed cuckoos from Tasmania and the southern regions of Australia migrate there to winter. However, some authors do not classify the red-tailed cuckoo as a migratory bird, but as a species that migrates opportunistically and thus opportunistically exploits rainy seasons and a given food supply.
The red-tailed cuckoo mainly lives in eucalyptus forests , but it can be found in numerous other habitats , such as in mangroves , in salt marshes along the coast, in tropical rainforests, open to bushy grasslands and parks .
food
The main food is caterpillars and other insects . As is typical for many cuckoos, it eats very hairy caterpillars. In addition, grasshoppers, wasps, earwigs and spiders are among its food spectrum. He also seems to eat berries occasionally.
He looks for his food mainly in low trees and bushes. In areas that are only loosely covered with trees, however, it also looks for food on the ground, and it catches flying insects by briefly flying up or jumping up. In a similar way, he collects caterpillars that hang from branches by thin threads.
Reproduction
Like all other Chrysococcyx species, it is a breeding parasite . Main host birds Fairy-Wrens and Acanthiza species. The territorial behavior of the females presumably leads to the monogamy of the red-tailed cuckoo, which is rather rare within brood parasites .
Red-tailed cuckoos have no specific breeding season; eggs are laid all year round. In South Australia, however, the red-tailed cuckoo lays most of its eggs between August and November. In central Australia there is an increased number of eggs being laid in spring and autumn, in northern Australia there is egg-laying every month except April and July.
During the respective breeding season, the females establish a territory in which they exclusively lay eggs in foreign nests. Eggs are mainly laid between 8 and 9 a.m. As with the cuckoo represented in Central Europe and the golden cuckoo , the red-tailed cuckoo also lay eggs within a few seconds, and the female then leaves the host bird's nest, carrying an egg of the host bird in her beak. The time in the nest is no longer than 3.3 to 5 seconds. Similar to the cuckoo, the females of the red-tailed cuckoo also eat eggs that have already been hatched as well as nestlings of their host bird species. Here, too, this presumably serves to force the host bird to lay a second clutch. The eggs of the red-tailed cuckoo are whitish and slightly pink, they also have slightly brownish-red speckles. With this coloration they resemble the eggs of a number of host birds, but especially the owl tail and Acanthiza inornata . a species from the family of the South Sea warblers . The eggs of the red-tailed cuckoo weigh just 1 gram.
After an incubation period of 12 to 13.5 days, the nestlings hatch from the eggs and are initially blind and naked. The breeding season is thus shorter than that of the most important host bird species. Nest beds weigh about 1.4 grams at the time of hatching. 24 to 30 hours after hatching, they begin to throw eggs and juveniles of the host bird out of the nest. You are still blind at this point, your eyes only open on the 4th day of your life. On the 14th day of life they are fully feathered, between the 15th and 19th day of life they leave the nest. Fledglings that have fledged very soon begin to actively search for hairy caterpillars. But they are also fed by the host bird outside of the nest. In the case of the turquoise taffeta this time lasts between four and 21 days, with Acanthiza inornata between 10 and 20 days.
In the nests of the turquoise tiger tail, a red-tailed cuckoo flies in 43 percent of cases, in Acanthiza inornata the percentage is 65%. In the case of the blue-breasted easel tail , a nestling hatches in 80 percent of the parasitized nests; in 76 percent of the parasitized nests, this nestling also flies. The magnificent eel tail is one of the very few species among the cuckoo host birds that are unable to recognize the nestling as their own offspring and then give up the nest. This can be traced back to the fact that the nestlings of the splendid teasel tail learn a specific begging call during their egg phase, which differs from that of the red-tailed cuckoo. Red-tailed cuckoo nestlings are unable to learn this begging call.
The influence of the red-tailed cuckoo on the breeding success of its host bird species is great. Johnson estimates based on studies that 20 percent of the nests of turquoise tails are parasitized by the red-tailed cuckoo. If a nestling hatches in 75 percent of the cuckoo eggs laid, the reproductive rate of this host bird species drops by 15 percent.
literature
- NB Davies: Cuckoos, Cowbirds and Other Cheats . T & AD Poyser, London 2000, ISBN 0-85661-135-2 .
- Johannes Erritzøe , Clive F. Mann, Frederik Brammer, Richard A. Fuller: Cuckoos of the World (Helm Identification Guides) . Christopher Helm Publishers Ltd, London 2012, ISBN 978-071-366-034-0 .
- Paul A. Johnsgard: The Avian Brood Parasites - Deception at the Nest . Oxford University Press, Oxford 1997, ISBN 0-19-511042-0 .
Web links
- BirdLife International: Species Factsheet - Horsfield's Bronze-cuckoo ( Chalcites basalis ) . Retrieved November 11, 2012.
- Videos, photos and sound recordings of Horsfield's bronze cuckoo (Chrysococcyx basalis) in the Internet Bird Collection
- Red-tailed cuckoo calls on Xeno-Canto
Individual evidence
- ↑ Chalcites basalis in the endangered Red List species the IUCN 2012. Posted by: BirdLife International, 2012. Accessed September 12, 2012 found.
- ↑ a b c Erhitzøe, Mann, Brammer, Fuller: Cuckoos of the World . P. 357.
- ↑ a b c d Erhitzøe, Mann, Brammer, Fuller: Cuckoos of the World . P. 358.
- ↑ a b Davies: Cuckoos, Cowbirds and Other Cheats. P. 89.
- ↑ Calls of the Red-tailed Cuckoo on Xeno-Canto , accessed on September 5, 2016
- ↑ Johnsgard: The Avian Brood Parasites . P. 234.
- ↑ Johnsgard: The Avian Brood Parasites . P. 235.
- ↑ a b c d e f g Erhitzøe, Mann, Brammer, Fuller: Cuckoos of the World . P. 359.
- ↑ NE Langmore; GJ Addock; RM Kilner: The spatial organization and mating system of Horsfield's bronze-cuckoos, Chalcites basalis . In: Animal Behavior . Vol. 74, No. 3. 2007. pp. 403-412.
- ↑ Davies: Cuckoos, Cowbirds and Other Cheats. P. 91.
- ↑ Johnsgard: The Avian Brood Parasites . P. 236.
- ↑ Johnsgard: The Avian Brood Parasites . P. 237.