Spiny ibis
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Spiny ibis ( Threskiornis spinicollis ) |
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| Threskiornis spinicollis | ||||||||||
| ( Jameson , 1835) |
The spiny ibis or straw - necked ibis ( Threskiornis spinicollis ) is an ibis living in Australia . The IUCN classifies the species as not endangered ( least concern ).
External features
The prickly ibis reaches a body length of 60 to 70 centimeters. The head, neck and the downward-curved beak account for about half of it. The wingspan is 100 to 120 centimeters. Spiked libbons weigh between 1.1 and 1.5 kilograms.
Similar to the Moluccan ibis, which is also native to Australia , its head is dark gray and featherless. The neck, on the other hand, is feathery white. It is named after the conspicuous, spiky yellowish feathers that the male has on the front neck and that reach up to the upper chest. The back and wings are brown with a green-purple tinge.
The sexual dimorphism is not very pronounced. The females lack the prickly yellowish feathers on the front neck, they are also somewhat smaller, which is noticeable when observing pairs. In females, the dark chest band is also not interrupted in white. Young birds not yet sexually mature have duller plumage, and their beak is also shorter and a little straighter. They do not show the plumage of adult sting bites until they are three to four years old.
Stingling ibites usually walk slowly with an almost horizontal posture with the head straight. They often boom. When looking for food, they use their beak to examine the ground for food. They fly longer distances high in the air, the flight is straight, with troops often forming a V-shaped formation. The slow and deep beats of the wings are interrupted by short gliding phases. In flight, the neck is extended. Taking advantage of the thermals, they occasionally reach altitudes of several hundred meters.
distribution and habitat
The spiny ibis is an endemic species of Australia, unlike the Moluccan ibis, it is not a stray visitor to New Zealand. In New Guinea, on the other hand, he meets regularly. The Australian range also includes the Norfolk and Lord Howe Islands . The spiny ibis is very widespread in Australia. It is only missing in the arid interior of Australia. Its range has increased over the past few decades. Above all, it has benefited from the conversion of previously forested areas into pasture and agricultural land, increasing irrigation systems and the construction of water reservoirs. Pasture land is only used by them if there are natural groups of trees nearby that the troops can use to rest. Farmers like to see the spiny ibis on pastures because it is considered to destroy pests. The spiny ibis is not very effective at destroying locust plagues, however.
Spiny ibises prefer wetlands and grasslands as habitats, but they can also be found on agricultural land, where they follow the plow to look for insects that have come to the surface. They rarely use the immediate coastal area as a habitat, and they are also relatively rare in the arid regions in the interior of Australia. However, water bodies that exist permanently or only for a short time are populated by them relatively quickly. Spiny ibites also use urban habitats and are found in gardens, on sports fields and along roadsides.
Spiked libites are part pullers. Parts of the population are resident birds and stay close to their breeding areas, a large part migrates over long distances at certain times of the year, a third part depending on local conditions. There are two main directions. One runs in a north-south direction between the south-east and north of Australia. The second runs between eastern Australia and the breeding grounds in inland Australia.
food
The food spectrum of the quilibite is very large. The composition depends on the local conditions. The food spectrum includes crustaceans, frogs, fish, beetles, grasshoppers, caterpillars, spiders and water snails. With their long beak they examine holes and crevices in the ground, tufts of grass and the shallow water zone. Spiny libbons also steal prey from their conspecifics. Stingling ibites spend around 75 percent of their time foraging for food. The focus of the activity falls on the morning and afternoon hours. They rest during the hottest time of the day.
Reproduction
Brood colonies of the sting bite are found in wetlands that are covered with reeds, bushes or trees. The nests are usually in trees; on islands or on the edge of wetlands, nests can also be on the ground. In eastern Australia, the rainy season is usually the trigger for the breeding season.
The spiny ibis breed from August to January in the south of the range, from February to May in the north. It lays two to three, rarely up to five eggs. Both parent birds are involved in the brood. The young hatch after 25 days and fledge after five weeks.
supporting documents
literature
- PJ Higgins (Ed.): Handbook of Australian, New Zealand & Antarctic Birds. Volume 1: Ratites to Ducks. Oxford University Press, Oxford 1990, ISBN 0-19-553068-3 .
Web links
- Threskiornis spinicollis in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 31 of 2009.
- Videos, photos and sound recordings on Threskiornis spinicollis in the Internet Bird Collection