Goldcock
| Goldcock | ||||||||
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Female of the great goldcock |
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| Systematics | ||||||||
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| Scientific name | ||||||||
| Rostratulidae | ||||||||
| Mathews , 1911 |
The golden snipes (Rostratulidae) are a family in the order of the plover-like (Charadriiformes). The family includes two species that are very different from each other in appearance and, above all, in way of life.
features
Goldcock are typical of the shape of the snipe . They are medium-sized birds (up to 28 cm) and have a long beak that curves slightly downwards. Of real snipe they are distinguished by the more colorful plumage, the shorter tail and long legs, as with Rails dangle the fly down. The flight is slow and seems awkward, it rarely leads over long distances and practically never at heights above 10 m. When in danger, golden snipes prefer to hide in a frozen stance, and only fly open when in extreme danger. The very long legs end in long, widely spread toes. Due to their large area, these help not to sink into the muddy ground. The white-spotted goldcock has webbed webs , the great- spotted goldcock does not. Both species can swim but rarely make use of this ability.
There are striking similarities in the plumage of both species. Both have a white eye ring that continues towards the back of the head. The plumage is dominated by reddish brown tones that shimmer metallic. The underside of both species is white.
A peculiarity of the old-worldly colored goldcock is the reverse sexual dimorphism : the females are bigger, heavier and brighter than the males. In the South American white-spotted goldcock, on the other hand, there is no externally visible sexual dimorphism at all.
distribution and habitat
Goldcock have a very large distribution area. The goldencock is widespread in large parts of Africa, in South, East and Southeast Asia as well as in the eastern half of Australia . The white-spotted goldcock inhabits the northern half of Argentina and Chile , the extreme south of Brazil, and Paraguay and Uruguay .
Goldcock are bound to water, so they need swamps, flood plains or the banks of stagnant water. Their habitats are often overgrown with dense vegetation and the water must be shallow. Also rice fields provide an ideal habitat for both species.
Way of life
activity
Outside the breeding season, goldcock are loners. They are mainly active at dawn and dusk, and also at night on moonlit nights. The black-and-white goldcock can be found exceptionally in broad daylight, but the white-spot goldcock never.
food
As an omnivore , goldcock eats both animal and vegetable foods. Invertebrates provide food for the animals, for example aquatic insects, snails, worms and crustaceans. Grasses predominate among the plants, including cultivated species such as rice. To search for food, the muddy ground is examined with the beak. The birds are constantly walking around.
Reproduction
Both species have completely different reproductive strategies. Polyandry prevails in the common goldcock ; only with very low population densities there are cases of monogamy. The white-spotted goldcock couple always live in monogamy .
The female mates with two to four males in the common goldcock. It is usually not involved in nest building, brooding or rearing young. After laying eggs, the female no longer takes care of the offspring, but continues to defend the territory in which its males breed. In contrast, with the white-spotted goldcock, both partners share all tasks. But even in the few cases of monogamous golden snipe, the partners share tasks.
The nest is a small pit that is laid out with soft parts of plants. The clutch consists of two to five eggs, the clutches of the yellow goldcock are larger than those of the white-spot goldcock. It is incubated for 15 to 20 days. The young birds flee the nest .
Tribal history
A fossil from the Eocene , Rhynchaeites messelensis , was initially mistaken for a goldencock, but later identified as a small ibis. The first known fossil woodcock to be found was Rostratula minator from the Pliocene of South Africa; this species was smaller than a spotted goldcock but larger than a white-spotted goldcock. With Rostratula pulia a European species is also known; she lived in the Miocene and is passed down from fossil finds in the Czech Republic.
Systematics
Nowadays, due to the considerable differences in lifestyle and morphology, it is customary to assign the two species to their own genera. The white-spotted goldcock is assigned to the genus Nycticryphes , the common goldcock to the genus Rostratula :
- White-spotted gold snipe ( Nycticryphes semicollaris ( Vieillot , 1816) )
- Northern goldcock ( Rostratula benghalensis ( Linnaeus , 1758) )
Sometimes, however, both species are placed in the genus Rostratula . It is also sometimes common to separate the Australian subspecies of the goldencock as a separate species, Rostratula australis .
The systematic position of the golden snipe was unclear for a long time. In many anatomical features they are reminiscent of rails , outwardly they have similarities to the snipe birds . However, there are a number of characteristics that the goldcock have in common with the jacana . First of all, there is the reverse sexual dimorphism of the goldencock, which is also prevalent in almost all species of jacana. In addition, the golden snipe and the jacana each have ten hand wings , while all other plover species have eleven.
Today it is believed that goldcock and jacana are sister groups . Both are sometimes grouped together in a superfamily Jacanoidea, and this taxon is in turn a sister group of the high altitude runners .
People and goldcock
Since gold snipes are also at home in rice fields, they live near people in many places. Goldcock was particularly popular in India during British colonial rule. It was a pure sport hunt, the animals shot were not used. In Argentina and Chile, on the other hand, the meat of the goldcock is eaten, albeit rarely.
Both species are not threatened because of their huge ranges. However, they have become rare locally, for example in India and Japan. This is likely to be related to the ongoing destruction of their habitats.
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:
- ↑ Storrs Olsen & Kimberley Eller: A new species of painted snipe (Charadriiformes: Rostratulidae) from the early Pliocene at Langebaanweg, southwestern Cape Province, South Africa . In: Ostrich 1989, No. 60, pp. 118-121
- ↑ Jiri Mlikovsky: Cenozoic Birds of the World. Part 1, Europe. ( Memento of the original from March 7, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF file, approx. 2.6 MB) Ninox, Prague 2002, ISBN 8090110538
- ↑ Per Ericson, Ida Envall, Martin Irestedt & Janette A. Norman: Inter-familial relationships of the shorebirds (Aves: Charadriiformes) based on nuclear DNA sequence data . In: BMC Evolutionary Biology 2003, Vol. 3, No. 16
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 .
