Moluccan ibis
| Moluccan ibis | ||||||||||
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Moluccan ibis ( Threskiornis molucca ) |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Threskiornis molucca | ||||||||||
| ( Cuvier , 1829) |
The Moluccan ibis ( Threskiornis molucca ) belongs to the ibis and was once considered a subspecies of the sacred ibis . He lives in Australia and the Southeast Asian island world.
The stock situation of the Australian White Ibis was in 2016 in the endangered Red List species the IUCN as not at risk ( least concern described).
Appearance
The Moluccan ibis is very similar to the sacred ibis. It reaches a body length of 65 to 75 centimeters and has a wingspan of 112 to 124 centimeters. Males weigh 1.7 to 2.5 kilograms and females 1.4 to 1.9 kilograms. The size difference is the only sexual dimorphism, but the body sizes of the two sexes overlap, so that size is not a sure differentiator.
The Moluccan ibis is largely white, with the exception of a few black feathers on the wings. The head is black and featherless.
Other ibises found in Australia are predominantly dark-pinnate. However, the flight of the spiny ibis is similar to that of the Moluccan ibis. In poor visibility conditions, especially when the beak is not clearly visible, the Moluccan ibis can be confused with different species of spoonbill .
Distribution area and habitat
The Moluccan ibis is native to the north and east as well as a small region in southwest Australia , Tasmania, southern New Guinea , the Moluccas , the Lesser Sunda Islands and the Solomon Islands . In New Zealand they are occasionally wanderers .
The habitat of the Moluccan ibis are inland wetlands, grasslands and protected coastal areas. It prefers to look for food in shallow water and muddy bank sections, but can also find it in more humid grasslands. The range of wetlands that provide suitable habitats for the Molukkenibis is very large. It can be found on running waters, billabongs, ponds, on floodplains and on larger lakes. Humid grassland or agricultural areas are mainly used by him if they have a rich food supply for invertebrates. He also uses salt water, preferring estuaries, mangrove swamps, salt pans and salt marshes and lagoons. It also uses human settlement space and occurs in gardens, on sports fields and along streets.
Adult molucca bites are resident birds in the southeast of Australia, but part migrants in the southwest of Australia. However, young birds migrate far. In contrast, nothing is known about the migration of the populations further inland and north of Australia. Due to the largely constant populations, which are reported for example from the Australian state of Victoria, it can be concluded that migratory movements are not very pronounced.
Reproduction
The Moluccan ibis breed in colonies on trees, in bushes or on the ground. The colonies can be very large, with up to 20,000 pairs. The nests can be built so close to each other that they touch and form nesting platforms that are used by several couples. Up to five nests have already been counted on one square meter. Moluccan bites are definitely territorial and defend their nest and the immediate nest environment. They are more tolerant of their nest neighbors than they are of intruders.
Basically, Moluccas are serially monogamous, but many copulations can be found outside of the regular couple relationship. Usually birds of neighboring nests mate, but most copulations take place after the time in which the females are ready to receive. Mating between Moluccan bites that have not yet brooded are relatively rare.
The duration of the couple relationship varies from person to person. In some birds it ends immediately after copulation, other pairs stay together until they have reared a brood, other pairs stay together for several broods in a season or even for up to three years. When they first breed, Moluccan Biss is usually three years old. In pairs that stay together, both parent birds breed and jointly care for the young birds for a period of four weeks.
The time of the breeding season depends on local conditions. In some regions, Moluccan Bites do not breed annually. 3 to 4 eggs are laid, larger clutches are usually due to the fact that two females have laid eggs in one nest. The laying interval between the individual eggs is 48 hours, and the eggs are usually laid at night. The brood lasts about 21 days. Newly hatched young birds weigh an average of 46.1 grams. Her eyes are still closed during the first days of life. The base of the beak is pink during the first two weeks of life and then becomes increasingly darker. At the age of three weeks, the young birds begin to form so-called kindergartens ( crèches ) in some regions . From this point on, they are no longer rowed, are active and climb around on the nest, but are still fed by the parent birds. As a rule, they leave the nest no later than the 30th day of life. After they have fled out, they are still near the nest. They also leave the colony an average of 21 days after leaving the colony. However, some young birds stay in the vicinity of the colony for months and are then occasionally fed by their parents.
The breeding success varies according to location and year. In Healesville in 1983/84 and 1986/86 only 85 young birds fledged from 100 nests. In the period 1983/84, however, there were 97 young birds per 100 nests. In 51 percent of the nests no young birds fledged, in the other nests, however, predominantly two young birds. The reenactment by predators was not the main cause of death, the young birds very often starved to death. Flooding or collapse of the nests also played a significant role.
food
The Moluccan ibis feed on reptiles , fish , crustaceans , large insects , snails , small mammals and occasionally carrion . The composition of the food is mainly determined by the respective habitat. They are not defending food territory. Antagonistic behavior within foraging troops is presumably exclusively a fight for prey, since Moluccan bites also steal food from one another.
While foraging for food, they walk slowly, examining the ground with their long beak or pecking food from the ground or the surface of the water. Picking behavior can be observed especially on grassland. Larger prey is crushed with the tip of the beak and then eaten quickly. Mussels are occasionally carried to rocks or tree trunks, held in place with the foot, and opened with blows with the beak.
supporting documents
literature
- PJ Higgins (Eds.): 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 moluccus in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed January 31 of 2009.
- Videos, photos and sound recordings of Threskiornis molucca in the Internet Bird Collection
Single receipts
- ↑ Threskiornis moluccus in the endangered Red List species the IUCN 2016 Posted by: BirdLife International, 2016. Retrieved on October 10, 2017th
- ^ Higgins, p. 1078
- ^ Higgins, p. 1079
- ^ Higgins, p. 1078 and p. 1079
- ↑ Higgins, p. 1081
- ^ Higgins, p. 1080
- ^ Higgins, p. 1082
- ^ Higgins, p. 1083
- ^ Higgins, p. 1082
- ^ Higgins, p. 1082
- ^ Higgins, p. 1084
- ^ Higgins, p. 1085
- ^ Higgins, p. 1085
- ^ Higgins, p. 1085
- ^ Higgins, p. 1085
- ^ Higgins, p. 1082 and p. 1083
- ^ Higgins, p. 1082