Spiny-tailed swift
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Prickly swift ( Hirundapus caudacutus ) |
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| ( Latham , 1802) |
The spiny-tailed swift ( Hirundapus caudacutus ) is a species of bird from the family of sailors (Apodidae). It is a large sailor that breeds from Siberia to Japan and the Himalayas . In the Himalayas, the species is resident , while the northern populations mainly summer in eastern Australia during the winter of the northern hemisphere . The plumage of the spiny-tailed swift is predominantly dark olive-brown; the light horseshoe pattern on the underside and the light, wide throat patch are striking. These plumage features and the characteristic shape allow a very simple determination of the species. The population of the spiny-tailed swift is considered stable and the species is not endangered.
With a top speed of 170 km / h in horizontal flapping flight, the spiny-tailed sailor is considered to be the fastest sailor; according to the current state of knowledge, it is even the fastest bird in the world in this discipline.
features
The body length is between 19 and 20 centimeters, the wing length between 195 and 225 millimeters. The weight determined was between 109 and 140 grams for males and between 101 and 125 grams for females. The combination of shape and plumage features make it easy to determine the species. The long wings are broad at the base and taper to a point. The body is quite strong, the head is relatively large and is stretched forward. The broad, short tail is cut straight and shows the eponymous tail spines, quills protruding over the flags of the control feathers .
The plumage is predominantly dark olive brown. Striking is the light horseshoe pattern on the underside, which is formed by the light under-tail ceilings and the light stripes on the flanks. All Hirundapus species show this feature, but the spiny-tailed swift also has a broad, strongly contrasting light throat spot that clearly distinguishes it from all other species of the genus. The species also shows a white stripe across the reins and forehead. On the upper side, especially in the lower area of the coat and on the back, there are lighter, gray-brown parts of the plumage that gradually darken towards the neck.
The flight of the spiny-tailed swift is characteristic. Fast, powerful flaps of wings accelerate the bird to the high speeds for which the species is known. The spiny-tailed swift flies very quickly on the move and when foraging, but gliding phases are also interspersed with it. Often you can see it flying at a much lower speed, while the wings are slightly bent down during long gliding phases.
The sexes do not differ in appearance. The forehead and reins of young birds are gray-brown instead of white. This distinguishing feature to the adult birds is also present in the annuals in a weakened form.
The call of the spiny-tailed swift is a fast, almost insect-like chatter ("trp-trp-trp-trp-trp-trp ...") and sounds much less harsh than the calls of the Apus species. The duration and speed of the call cascades are different.
Spreading and migrations
The Asian distribution area is divided into two disjoint sub-areas, the birds of the northern population are long-distance migrants , those of the southern resident birds .
The northern population breeds in an area from central Siberia to Japan . The distribution area extends from the Wassjugan valley in the west east through Mongolia to northern China , in the east of the Asian mainland the distribution extends south to the Korean peninsula . The species also occurs on Sakhalin , the Kuril Islands and the Japanese islands of Hokkaidō and Honshū , on the latter only in the north.
In the Himalayas the spiny-tailed swift breeds from west to east from Hazara in Pakistan via Nepal , Sikkim , Bhutan , Arunachal Pradesh to the west of Sichuan and Yunnan .
The northern populations predominantly over-summer in eastern Australia, to a lesser extent in southern New Guinea . You travel through China, the east of Thailand and the Indochinese peninsula . The lack of sightings on the Indian subcontinent makes it clear that the birds from central Siberia first fly around the Asian mountains to the east before turning south. Sailors leave the breeding area in the northern hemisphere mainly in September, migrating across Southeast Asia between September and November. As a rule, the birds reach Australia via the Torres Strait , more rarely via the Arafura Sea . The average first sighting in Australia is on October 22nd, the southern part of their winter quarters in Victoria and Tasmania are mainly in December. The migration begins in March, the arrival in the breeding area occurs between April and mid-May.
The spiny-tailed swift is rarely found in Western Europe as a stray visitor, most of the sightings occur in Great Britain .
habitat
The tree-breeding spiny-tailed swift occurs in the Himalayas at altitudes between 1500 and 4000 meters. There he goes in search of food over higher grasslands and river valleys. In Bhutan the species can be found regularly over subtropical deciduous and mixed forests, which are at an altitude between 1000 and 2800 meters.
In Siberia , wooded lower areas and hills with open spaces represent the habitat of the spiny-tailed swift. It undertakes extensive daily migrations in search of food and also crosses very different habitats. Mainly the weather determines the altitude range of the foraging, the snow line is not exceeded.
In its winter quarters in Australia, the spiny-tailed swift occurs both in the mountains and in the coastal area. In the Snowy Mountains , which are free of snow at the time in question, the species is common over 1800 meters and regularly between 1500 and 1800 meters. The spectrum of hunting habitats ranges from densely forested areas to open habitats such as farmland, heathland or moorland . In the tropical rainforests of the lowlands of Papua New Guinea , the spiny-tailed swift can be found over forest edges or tree-free areas.
Behavior and food acquisition
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Swarming blue spruce wasps ( Sirex noctilio ) are among the prey animals in Australia
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Like all sailors, spiny-tailed swifts drink in- flight, here on Lake Samsonvale in southeast Queensland
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During the breeding season, the spiny-tailed swift is far less sociable than other sailors. It can be found in larger flocks on the migration and in winter quarters, but even during this time it is not uncommon to observe individual birds. Mixed swarms are mainly formed with other Hirundapus species, a non-species exception is the Pacific sailor, which is often on the move with the spiny-tailed sailor.
In addition to the chases that can be observed among many sailors, in which two or even three birds are involved, another form of sightseeing has been observed in the spiny-tailed sailor in Australia, which - although outside the breeding area - may be related to finding a partner. One or more birds in a group plunge almost vertically into the depths one after the other, only to regain their original height after a dive of about 12 meters with violent wing flapping.
Like all sailors, spiny-tailed swifts hunt insects or arachnids that are caught in the air. For food acquisition, the birds prefer to use areas with rising air currents, which can be caused by thermals or a bush fire . The following insects were found to be prey: beetles , cicadas , wasps , two-winged birds , moths , short-antennae terrors (especially locusts ) as well as swarming ants and termites .
Reproduction
Tree hollows or cave-like niches in the upper area of conifers are used as breeding grounds; the species also nests in the crevices of rock walls. A shallow hollow at the bottom of the cave serves as a nest, and a recess is dug in the material that has been piled up for this purpose. Otherwise little is known about the breeding behavior, breeding caves of other species are obviously used, in Pakistan two pairs have been observed inspecting old woodpecker caves. The laying time is mainly between late May and mid-June. The clutch size is usually two eggs, but up to seven eggs have also been found. Incubation begins after the first egg has been deposited. The average egg size was determined to be 32.3 × 22.3 millimeters. The incubation time is 40, the nestling time between 40 and 42 days. Both sexes participate equally in the breeding business.
Causes of mortality, existence and exposure
Sometimes spiny-tailed swifts are captured by birds of prey or owls , in Australia this has been proven for the marsh harrier ( Circus approximans ), the Australian tree falcon ( Falco longipennis ), the peregrine falcon ( Falco peregrinus ) and the bark owl ( Ninox connivens ). Also in Australia, collisions with overhead lines or other obstacles have occasionally been identified as a cause of death. Much more important in this context is certainly the long distance to be covered between the breeding area and winter quarters for migrating birds, which in particular also leads over some of the most densely populated areas on earth.
The spiny-tailed swift is quite rare in the Himalayas and only occurs in certain areas. Within the northern range, the frequency increases from west to east. In the winter quarters in Australia the species is locally common.
BirdLife International estimates the size of the range at approximately 6.1 million square kilometers, the population is classified as stable, therefore and due to the large range, the species is not considered endangered. In the years 1977–1981 and 1998–2002, a decreasing distribution and frequency of the guest birds was observed in the east and south-east of Australia and this could be an indication of a general population decline, since the birds that overwinter in Australia form a large part of the total population.
Systematics
The genus Hirundapus consists of four large to very large species of sailors. Both the very large swift and purple swift , as well as the two somewhat smaller species of the genus, the spiny-tailed swift and the gray-throated swift , each form a superspecies .
The populations in the Himalayas belong to the subspecies H. c. nudipes on. This differs from the nominate form mainly in that the light stripe on the reins and forehead is missing, the representatives of the subspecies are uniformly dark on the head. The plumage areas on the coat and back are also less light and more brown than gray. The underside and the coverts of the underside of the wing are a little darker than in the nominate form.
literature
- Phil Chantler, Gerald Driessens: A Guide to the Swifts and Tree Swifts of the World . Pica Press, Mountfield 2000; ISBN 1-873403-83-6
- Josep del Hoyo , Andrew Elliot and Jordi Sargatal (eds.): Handbook of the Birds of the World. Volume 5: Barn-owls to Hummingbirds. Lynx Edicions, 1999, ISBN 84-87334-25-3 .
Individual evidence
- ↑ a b BirdLife International: Species Factsheet - White-throated Needletail ( Hirundapus caudacutus ) . Retrieved October 7, 2009.
- ↑ del Hoyo et al .: Handbook of the birds of the world . Page 390, see literature
- ↑ thetravelalmanac.com: The world's fastest birds
- ↑ John Gooders: Birds of the World. Volume 5, 1971, page 1407
- ↑ a b c d e f g h i j k l m n o Chantler, Driessens: A Guide to the Swifts and Tree Swifts of the World . Page 172ff, see literature
- ↑ a b c d e f Australia Government, Department of the Environment, Water, Heritage and the Arts : Hirundapus caudacutus - White-throated Needletail. Species Profile and Threats Database, Canberra, Australia, accessed December 22, 2009
- ↑ JL Madden: Avian Predation of the Woodwasp, Sirex noctilio F., and its Parasitoid Complex in Tasmania. In: Australian Wildlife Research. 9: 135-144 ( online )
- ^ KG Simpson, DJ Noonan: Diving display flights of the Spine-tailed Swift, Hirundapus caudacutus. The Emu. 67: 27-31, 1967 ( abstract )
- ↑ Chantler, Driessens: A Guide to the Swifts and Tree Swifts of the World. Page 24, see literature
Web links
- Hirundapus caudacutus in the endangered Red List species the IUCN 2009. Posted by: BirdLife International, 2008. Accessed on October 5 in 2009.
- Stingtail Swift's feathers
