Sun rail
| Sun rail | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
.JPG)
Sun rail ( Eurypyga helias ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name of the family | ||||||||||||
| Eurypygidae | ||||||||||||
| Selby , 1840 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Eurypyga | ||||||||||||
| Illiger , 1811 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Eurypyga helias | ||||||||||||
| ( Pallas , 1781) |
The sun rail ( Eurypyga helias ) is a species of bird from the tropics of Latin America . Despite its name, it is not closely related to the rails . It is relationally isolated and therefore forms its own family, which was traditionally assigned to the crane birds , but is now placed in the order Eurypygiformes together with the kagu .
features
A sun rail becomes 43 to 48 cm long and weighs 180 to 220 g. It bears a distant resemblance to the unrelated herons ; this is especially true of the long, slender beak. The neck is slender and of medium length, but the legs are shorter than those of herons.
The plumage shows hardly any differences between males and females. The top has a fine gray-brown-black cross banding, which from a distance makes a predominantly gray impression. Yellowish-brown colors predominate on the underside. The tail has two strong black transverse bands on a gray base color, lined with rust brown in front. The head is predominantly black with a white throat and two white longitudinal bands above and below the eye. When the wings are opened, a conspicuous pattern of spots becomes visible on the wing feathers, which consists of two large rust-brown spots on each side, lined with black on the back, on a yellowish-brown base color. This is somewhat reminiscent of the eyespots of some butterflies and may serve as a deterrent to enemies, similar to these.
The large, rounded wings enable fast flight with long gliding phases. Most of the time, the sun rail stays close to the surface of the water.
distribution and habitat
The Sonnenralle inhabits the tropical lowlands and hill countries of Central and South America up to an altitude of about 1800 m. Habitat are river and lake banks within tropical rainforests .
There are three separate areas of distribution. The main area includes the lowland and hill regions in the catchment area of the Amazon and Orinoco , south to Bolivia and Mato Grosso , as well as the countries of Guyana . A second sub-area occupies Central America, on the Caribbean side to the north to the extreme south of Mexico , on the Pacific side to Costa Rica , as well as a coastal strip in the northwest of Colombia and in the west of Ecuador . The third and smallest sub-area comprises the Peruvian regions of Junín and Cusco .
Way of life
nutrition
Sunbeams seek their prey by walking slowly along the forest floor or in shallow water. They often freeze in motion. When they see a prey, they strike at lightning speed.
The food is exclusively animal. Invertebrates make up the majority of this, but vertebrates are also eaten to a not inconsiderable proportion. The preyed invertebrates mainly include animals living near and in the water such as dragonflies and their larvae, water beetles, snails, crustaceans and worms, but also spiders, butterflies, flies and cockroaches. The vertebrates that are eaten are mainly small fish, tadpoles and frogs, as well as small lizards such as anoles and amives .
Reproduction
Outside the breeding season, sun claws are strictly loners. During the breeding season, however, the pairs get together and stay together until the young are fully fledged. Little is known about pairing. It is considered possible that Sonnenrallen mate with the same partners every year, i.e. live in permanent monogamy . They use the same breeding grounds year after year. At the beginning of the breeding season, sunrays often fly over the treetops and give out loud calls that sound like 'kak-kak-kak'; it is believed that these are courtship flights.
The nest is built at a height of 1 to 7 m and has a size of 22 × 17 cm. It consists of leaves, moss, and most of all, mud that holds the nest together and attaches it to the branch. Sometimes seedlings sprout from this mud, so that green plants grow out of the nest and are useful in its camouflage. The female lays one or two beige-colored eggs with reddish spots that are 4.3 × 3.4 cm in size. The incubation period is 30 days, both partners participate equally.
The boys are initially very dependent ( nestling ) and not able to move independently. They are fed by the adult birds, from whose beaks they take their food. They take 22 to 30 days to fledge. During this time, young sun claws are extremely vulnerable to danger. Enemies include capuchin monkeys , tayras , grisons , ocelots, and birds of prey . The parent birds try to defend the nest with an imposing gesture in which they spread their wings and show the attacker the eye-spot pattern, fan-like the tail and lower the chest. They also try to lure an enemy away from the nest by simulating a wing injury.
The maximum service life is thirty years.
Systematics
External system
Traditionally, the sun rail was assigned to the crane birds . The name assignment to the rails is only available in German. In English this bird is called Sunbitter , so it is classified as a dommel . In fact, the zoologist Peter Simon Pallas described the sun rail in 1781 as Ardea helias , placing it in the heron genus.
The relationship of the sun rail was long controversial among the crane birds. Recently, there has been increasing evidence that the sun rail is not closely related to railing and cranes, but rather forms a common clade with the kagu and the fossil genera Messelornis and Aptornis . The kagu, an endemic bird of New Caledonia , would thus be the sister species of the sun rail. The kagu and the sun rail are perhaps the last remnants of what was once a much larger clade of birds that spread across Gondwana and was separated by the drifting apart of the continents.
Recently, the sun rail was placed in the new order Eurypygiformes along with the kagu , which was also recognized by the International Ornithological Congress and the American Ornithologists' Union .
Internal system
There are three subspecies that can be clearly distinguished:
- Eurypyga helias helias in Amazonia and northern South America; the back plumage is striped beige and black; the legs are yellow to orange.
- Eurypyga helias major in Central America as well as in Colombia and Ecuador; largest subspecies; the dorsal plumage is striped gray and black; the legs are red.
- Eurypyga helias meridionalis in Peru; smallest subspecies; resembles major , but the black stripes are thinner; the legs are orange.
At times, helias and major were also viewed as different species, but this is no longer common today.
People and sunrays
Due to the destruction of the rainforests, the habitat of the sunrays is also disappearing. Their total population lives in a distribution area of 8,500,000 km² and is therefore not threatened. The IUCN has it in the not endangered status .
The Indian peoples of Brazil and Venezuela were and are sometimes kept half-tame sun racks. Since they eat flies and other insects in the villages, they are considered useful.
The sun rail has been kept in European zoos since the 19th century. The London zoo was the first to breed in Europe in 1865.
Sources and further information
Sources cited
Most of the information in this article is taken from the source given under literature; the following sources are also cited:
- ^ Carrol L. Henderson: Field guide to the wildlife of Costa Rica . University of Texas Press, 2002. ISBN 029273459X
- ↑ Joel Cracraft: Gondwana genesis: a combination of molecular data, anatomical evidence, and knowledge of ancient geography is providing new answers to the contentious issue of when? And where? Modern birds arose. Natural History, Dec, 2001 Gondwana genesis: a combination of molecular data, anatomical evidence, and knowledge of ancient geography is providing new answers to the contentious issue of when ?? and where modern birds arose ( Memento from July 13, 2012 in Web archive archive.today )
- ↑ Bradley C. Livecey: A phylogenetic analysis of the Gruiformes (Aves) based on morphological characters, with an emphasis on the rails (Rallidae). Philosophical Trans. Royal Society London B (1998) 353, pp. 2077-2151
- ^ Frank Gill and Minturn Wright: BIRDS OF THE WORLD Recommended English Names. Princeton University Press, 2006, ISBN 0713679042
- ↑ WorldBirdNames.org IOC World Bird List ( Memento of the original from May 22, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ AOU Committee on Classification and Nomenclature (North & Middle America) ( Proposals 2008-C PDF; 109 kB ).
- ↑ Eurypyga helias in the IUCN Red List of Threatened Species 2011.2. Listed by: BirdLife International, 2009. Retrieved November 16, 2011.
- ↑ W. Grummt, H. Strehlow (Ed.): Zoo animal keeping birds. Verlag Harri Deutsch, Frankfurt am Main 2009, ISBN 978-3-8171-1636-2 , p. 280.
literature
- Josep del Hoyo et al .: Handbook of the Birds of the World. Volume 3: Hoatzins to Auks. Lynx Edicions, 1996, ISBN 84-87334-20-2 .
Web links
- Videos, photos and sound recordings of Eurypyga helias in the Internet Bird Collection