Christmas Island Owl
| Christmas Island Owl | ||||||||||
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Christmas Island Bush Owl ( Ninox natalis ) |
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| Scientific name | ||||||||||
| Ninox natalis | ||||||||||
| Lister , 1888 |
The Christmas Boobook ( Ninox natalis ) is a species of the genus of Buschkäuze . It occurs exclusively on the remote Australian Christmas Island . It is the only species of owl found on this island.
The Christmas Island bush owl is closely related to the bush owls of Southeast Asia and Australia. It was described as an independent species as early as 1888 by Joseph Jackson Lister . It was not until 1998, however, that DNA studies confirmed that this species differs from the other species to such an extent that the species status is justified. It had previously been suspected that this species could be a subspecies of the Moluccan owl ( Ninox squamipila ).
The IUCN classifies the Christmas Island gray owl as endangered ( vulnerable ) because of its small distribution area .
features
The females of the Christmas Island Owl reach a body length between 27 and 29 centimeters. The males stay a little smaller and reach a body length between 26 and 28 centimeters. The tail is 12.7 inches long in the females and 11.9 inches in the males. The weight of this species of owl is between 140 and 150 grams.
The upper side of the body is a strong rust brown with dark spots on the elytra and shoulders. The underside of the body is red-brown with white transverse bands. The legs are feathered. The face is brownish white with an indistinct gray face veil . The wax skin of the beak is light gray to lemon yellow. The beak is gray.
distribution
The Christmas Island gray owl is limited in its distribution to the Christmas Island. This is a 135 km², politically part of Australia island in the Indian Ocean . It is located 350 km south of Java and 2616 km northwest of Perth . The island is known for its endemic species: of the 23 bird species found on this island, 9 species breed only on this island. In addition to the Christmas Boobook these are around the Christmas Island Frigatebird ( Fregata andrewsi ), the Abbott's Booby ( Papasula abbotti ), the Christmas Imperial Pigeon ( Ducula whartoni ) and a subspecies of the bands hawk , the Christmas Island tapes hawk ( Accipiter fasciatus natalis ) and a Subspecies of the South Sea Thrush , the Christmas Island South Sea Thrush ( Turdus poliocephalus erythropleurus ). The white-tailed tropical bird ( Phaethon lepturus fulvus ), which adorns the flag of the territory as a heraldic animal, is also endemic to this island .
Christmas Island is very rich in phosphate and has been greatly changed by the phosphate mining: the tropical rainforest has disappeared on a quarter of the island, leaving a karst landscape that is only gradually showing trees again. In 1987 phosphate mining was stopped on the island and in 1990 62 percent of the island was placed under protection with the Christmas Island National Park. However, the island's fauna is still under threat: Today the yellow spider ant ( Anoplolepis gracilipes ) introduced from Africa represents the greatest threat to the autochthonous fauna. Means are being sought to contain this ant species, which is already widespread on a quarter of the island.
Way of life
The habitat of the Christmas Island owl is the rainforest. However, it also hunts in areas where there are no more trees. The greatest population density is in the still undestroyed forest areas. The lowest population density is found in the secondary forest, which gradually covers the regions of the island that have been severely affected by phosphate mining.
It feeds mainly on insects, including praying mantises, beetles and cockroaches introduced near human settlements. Most of the insects it catches are two centimeters in size. Skinks, geckos, small songbird species, small bats and the Christmas Island crabs that occur on the island play a lesser role in its diet . He goes in search of food at dusk. In the vicinity of human settlements, he also hunts in the light of street lamps.
Very little is known about the breeding behavior , but it is believed that the Christmas Island Bush Owl breeds in hollow trees in all parts of the island. The breeding season falls between July and August. The pups fledge around 68 to 77 days after hatching and are then dependent on their parents for another two and a half months. He has a strong territorial instinct and defends his territory together with his partner. This is done by shouting loudly.
Protection and threat
The Christmas Island gray owl is considered endangered (fewer than 1,000 individuals live on the island) and its population is believed to have decreased by a quarter since the Christmas Islands were settled. However, he now lives in the protected Christmas Island National Park . However, in order to guarantee comprehensive protection for this species, more research must first be carried out into the life and imminent danger of extinction of these owls.
literature
- Ronald Strahan: Cuckoos, Nightbirds & Kingfishers of Australia . Angus & Robertson, Sydney 1994, ISBN 0-207-18522-0 .
Web links
- Ninox natalis inthe IUCN Red List of Threatened Species 2016.1. Posted by: BirdLife International, 2016. Retrieved December 17, 2016.
- Markus Kappeler - Christmas Island Bush Owl
- The Christmas Island Owl calls on Xeno-Canto
Single receipts
- ^ A b Strahan: Cuckoos, Nightbirds & Kingfishers of Australia . P. 83.
- ↑ Janette A Norman, L Christidis, M Westerman, FA Richard Hill: Molecular data confirms the species status of the Christmas Island Hawk-Owl Ninox natalis. . In: CSIRO Publishing (ed.): Emu . 98, No. 3, 1998, pp. 197-208. doi : 10.1071 / MU98028 .
- ^ A b Ninox natalis in the IUCN Red List of Threatened Species 2016.1. Posted by: BirdLife International, 2016. Retrieved December 17, 2016.
- ↑ a b c d Strahan: Cuckoos, Nightbirds & Kingfishers of Australia . P. 84.
- ↑ Christmas Island National Park website, “Birds” section, accessed December 17, 2016
- ↑ Information on bird life PDF file (2.20 MB, English), accessed on December 17, 2016
- ↑ Christmas Island National Park Conservation projects section “Yellow crazy ants”, accessed on December 16, 2016