Norfolk Island Boobook
Encyclopedia
The Norfolk Boobook also known as the Norfolk Island Boobook, Norfolk Island Owl or Norfolk Island Morepork, was a bird in the true owl family endemic to Norfolk Island
, an Australia
n territory in the Tasman Sea
between Australia and New Zealand
. It is an extinct
subspecies
of the Southern Boobook
(Ninox novaeseelandiae). However, although the taxon is extinct, its genes live on in the descendants of the hybrid offspring of the last female bird, which was sighted for the last time in 1996.
with mottled plumage. It was smaller, darker and more reddish in colouring than the Australian subspecies, with much spotting. However, it was slightly larger than the nominate subspecies from New Zealand; female boobooks are larger than the males, with New Zealand females comparable in size to Norfolk Island males, a factor which gave rise to sexing difficulties with hybrid birds in the conservation management program.
, which was largely cleared in the 19th century following human settlement. Most of the remaining forest lies within the small (4.65 km²) Mt Pitt section of the Norfolk Island National Park
.
s. Recorded clutch sizes from Norfolk Island range from one to three eggs, with two being usual.
for nesting in. There was also competition for nest hollows with feral
honey bee
s and introduced Crimson Rosella
s. By 1986 the population had been reduced to a single female bird, named "Miamiti" after a matriarch of the Norfolk Island people. As part of a program to attempt to conserve at least some of the genes of the insular subspecies, two male Southern Boobooks (Moreporks) of the nominate New Zealand subspecies, Ninox novaeseelandiae novaeseelandiae, were introduced to the island as mates for the female. The males were sourced from the New Zealand subspecies rather than one of the Australian subspecies as it was discovered that it was more closely related to the Norfolk Island taxon. Nest box
es were also provided. One of the introduced males disappeared a year after introduction but the other successfully mated with the female with the pair producing fledged chicks in 1989 and 1990. The original female disappeared in 1996 but, by then, there was a small hybrid population of about a dozen birds. These birds and their descendants continue to exist on the island.
Norfolk Island
Norfolk Island is a small island in the Pacific Ocean located between Australia, New Zealand and New Caledonia. The island is part of the Commonwealth of Australia, but it enjoys a large degree of self-governance...
, an Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n territory in the Tasman Sea
Tasman Sea
The Tasman Sea is the large body of water between Australia and New Zealand, approximately across. It extends 2,800 km from north to south. It is a south-western segment of the South Pacific Ocean. The sea was named after the Dutch explorer Abel Janszoon Tasman, the first recorded European...
between Australia and New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
. It is an extinct
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
of the Southern Boobook
Southern Boobook
The Southern Boobook , also called the Mopoke, Morepork, Ruru or Tasmanian Spotted Owl, is a small brown owl found throughout New Zealand, Tasmania, across most of mainland Australia and in Timor, southern New Guinea and nearby islands.The bird has almost 20 alternative common names, most of which...
(Ninox novaeseelandiae). However, although the taxon is extinct, its genes live on in the descendants of the hybrid offspring of the last female bird, which was sighted for the last time in 1996.
Description
The Norfolk Boobook was very similar in appearance to other subspecies of the Southern Boobook, being a small brown hawk owlNinox
Ninox is a genus of owls comprising about 20 species found in Asia and Australasia. Many species are known as hawk owls or boobooks...
with mottled plumage. It was smaller, darker and more reddish in colouring than the Australian subspecies, with much spotting. However, it was slightly larger than the nominate subspecies from New Zealand; female boobooks are larger than the males, with New Zealand females comparable in size to Norfolk Island males, a factor which gave rise to sexing difficulties with hybrid birds in the conservation management program.
Habitat
The owl inhabited the island’s subtropical rainforestRainforest
Rainforests are forests characterized by high rainfall, with definitions based on a minimum normal annual rainfall of 1750-2000 mm...
, which was largely cleared in the 19th century following human settlement. Most of the remaining forest lies within the small (4.65 km²) Mt Pitt section of the Norfolk Island National Park
Norfolk Island National Park
Norfolk Island National Park is a protected area of 6.50 km² established in 1984 and managed by the Commonwealth of Australia. It comprises two sections, the Mount Pitt section on Norfolk Island in the South Pacific Ocean with an area of 4.60 km² and the neighbouring 1.90 km² Phillip Island, as...
.
Breeding
Boobooks breed in tree hollowTree hollow
A tree hollow or tree hole is a semi-enclosed cavity which has naturally formed in the trunk or branch of a tree. These are predominantly found in old trees, whether living or not...
s. Recorded clutch sizes from Norfolk Island range from one to three eggs, with two being usual.
Feeding
Boobooks feed on small vertebrates, especially birds and mammals, as well as invertebrates.Status and conservation
The population of the Norfolk Boobook declined with the clearance and modification of its forest habitat, especially the felling of large trees with suitable hollowsTree hollow
A tree hollow or tree hole is a semi-enclosed cavity which has naturally formed in the trunk or branch of a tree. These are predominantly found in old trees, whether living or not...
for nesting in. There was also competition for nest hollows with feral
Feral
A feral organism is one that has changed from being domesticated to being wild or untamed. In the case of plants it is a movement from cultivated to uncultivated or controlled to volunteer. The introduction of feral animals or plants to their non-native regions, like any introduced species, may...
honey bee
Honey bee
Honey bees are a subset of bees in the genus Apis, primarily distinguished by the production and storage of honey and the construction of perennial, colonial nests out of wax. Honey bees are the only extant members of the tribe Apini, all in the genus Apis...
s and introduced Crimson Rosella
Crimson Rosella
The Crimson Rosella is a parrot native to eastern and south eastern Australia which has been introduced to New Zealand and Norfolk Island. It is commonly found in, but not restricted to, mountain forests and gardens. The species as it now stands has subsumed two former separate species, the Yellow...
s. By 1986 the population had been reduced to a single female bird, named "Miamiti" after a matriarch of the Norfolk Island people. As part of a program to attempt to conserve at least some of the genes of the insular subspecies, two male Southern Boobooks (Moreporks) of the nominate New Zealand subspecies, Ninox novaeseelandiae novaeseelandiae, were introduced to the island as mates for the female. The males were sourced from the New Zealand subspecies rather than one of the Australian subspecies as it was discovered that it was more closely related to the Norfolk Island taxon. Nest box
Nest box
A nest box, also spelled nestbox is a man-made box provided for animals to nest in. Nest boxes are most frequently utilized for wild and domesticated birds, in which case they are also called birdhouses, but some mammalian species may also use them. Birdhouses are the most common types of nest...
es were also provided. One of the introduced males disappeared a year after introduction but the other successfully mated with the female with the pair producing fledged chicks in 1989 and 1990. The original female disappeared in 1996 but, by then, there was a small hybrid population of about a dozen birds. These birds and their descendants continue to exist on the island.