Norfolk boobook

Last updated

Norfolk boobook
Norfolk Boobook.jpg
Illustration by Henrik Grönvold
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Genus: Ninox
Species:
Subspecies:
N. n. undulata
Trinomial name
Ninox novaeseelandiae undulata
(Latham, 1801)

The Norfolk boobook (Ninox novaeseelandiae undulata), also known as the Norfolk Island boobook, Norfolk Island owl or Norfolk Island morepork, is a bird in the true owl family endemic to Norfolk Island, an Australian territory in the Tasman Sea between Australia and New Zealand. It is a subspecies of the morepork (Ninox novaeseelandiae).

Contents

Although the taxon is extinct as a pure lineage, 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. [2] Due to the genetic closeness of the Norfolk and New Zealand moreporks, with the majority of original Norfolk boobook DNA being preserved in modern birds, the subspecies is thus considered extant by the International Ornithological Congress and the EPBC Act despite the hybridization. [3] [4] [5]

Description

Watercolour by James Stuart, 1839 Ninox novaeseelandiae undulata.jpg
Watercolour by James Stuart, 1839

The Norfolk boobook is very similar in appearance to the New Zealand and Tasmanian boobooks, being a small brown hawk owl with mottled plumage. It is smaller, darker and more reddish in colouring than the Tasmanian boobook, with much spotting. [6] However, it is 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. [7]

Habitat

The owl inhabits the island's subtropical rainforest, 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.

Behaviour

Breeding

Boobooks breed in tree hollows. Recorded clutch sizes from Norfolk Island range from one to three eggs, with two being usual. [8]

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 hollows for nesting in. There was also competition for nest hollows with feral honey bees and introduced crimson rosellas. [9] By 1986 the population had been reduced to a single female bird, named "Miamiti" after a matriarch of the Norfolk Island people. [10] As part of a program to attempt to conserve at least some of the genes of the insular subspecies, two male 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. [11] [12] Nest boxes 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. By 2018, between 45-50 birds were known, although the population has been inbred and aging with no new recruitment since 2012. [13]

The New Zealand and Norfolk boobooks are considered to be very closely related, with some debate over whether it should even be recognized as a separate taxon; they can only be distinguished by their physical features. [3] For this reason, the International Ornithological Congress does not consider this subspecies to be extinct as it was saved by the hybridization program, despite it no longer surviving as a genetically pure lineage. Genetic analysis indicates that half the nuclear genome and all the mtDNA of the original Norfolk boobook persists in the modern birds, marking it a special case of a taxon that can still be considered extant in a hybrid form. This may be due to the last surviving pure bird being a female, allowing for the mtDNA to be fully passed on. [4] [5]

Notes

  1. "Species Profile and Threats Database Ninox novaeseelandiae undulata — Norfolk Island Boobook, Norfolk Island Morepork, Southern Boobook (Norfolk Island)". Canberra: Department of Agriculture, Water and Environment. Retrieved 2022-08-22.
  2. Garnett & Crowley, p.365
  3. 1 2 Norman, Janette; Olsen, Penny; Christidis, Les (1998). "Molecular genetics confirms taxonomic affinities of the endangered Norfolk Island Bookbook Owl Ninox novaeseelandiae undulata". Biological Conservation. 86 (1): 33–36. doi:10.1016/S0006-3207(98)00012-3.
  4. 1 2 "Owls – IOC World Bird List" . Retrieved 2022-08-24.
  5. 1 2 Garnett, Stephen T.; Olsen, Penny; Butchart, Stuart H. M.; Hoffmann, Ary A. (2011). "Did hybridization save the Norfolk Island boobook owl Ninox novaeseelandiae undulata?". Oryx. 45 (4): 500–504. doi: 10.1017/S0030605311000871 . ISSN   1365-3008.
  6. Higgins, p.853.
  7. Double & Olsen, pp.283-284.
  8. Higgins, p.866.
  9. Garnett & Crowley, p.365
  10. Anon, p.20.
  11. Double & Olsen, p.283.
  12. Norman et al, p.33.
  13. "Norfolk Island boobook owl". Department of Climate Change, Energy, the Environment and Water. 2018.

Related Research Articles

Morepork Species of owl

The morepork, also called the ruru, is a small brown owl found in New Zealand, Norfolk Island and formerly Lord Howe Island. Its name is derived from its two-tone call. The bird has almost 20 alternative common names, including mopoke and boobook—many of these names are onomatopoeic, as they emulate the bird's distinctive two-pitched call. Three subspecies of the morepork are recognized, one of which is extinct and another that exists only as a hybrid population.

Laughing owl Extinct species of owl

The laughing owl, also known as whēkau or the white-faced owl, was an endemic owl of New Zealand. Plentiful when European settlers arrived in New Zealand, its scientific description was published in 1845, but it was largely or completely extinct by 1914. The species was traditionally considered to belong to the monotypic genus SceloglauxKaup, 1848, although recent genetic studies indicate that it belongs with the boobook owls in the genus Ninox.

Australian boobook Species of owl native to Australia

The Australian boobook, which is known in some regions as the mopoke, is a species of owl native to mainland Australia, southern New Guinea, the island of Timor, and the Sunda Islands. Described by John Latham in 1801, it was generally considered to be the same species as the morepork of New Zealand until 1999. Its name is derived from its two-tone boo-book call. Eight subspecies of the Australian boobook are recognized, with three further subspecies being reclassified as separate species in 2019 due to their distinctive calls and genetics.

<i>Ninox</i> Genus of birds

Ninox is a genus of true owls comprising about 35 species found in Asia and Australasia. Many species are known as hawk-owls or boobooks, but the northern hawk-owl is not a member of this genus.

Barking owl Species of owl

The barking owl, also known as the winking owl, is a nocturnal bird species native to mainland Australia and parts of New Guinea and the Moluccas. They are a medium-sized brown owl and have a characteristic voice with calls ranging from a barking dog noise to a shrill human-like howl of great intensity.

Christmas boobook Species of owl

The Christmas boobook, also known more specifically as the Christmas Island hawk-owl, is a species of owl in the family Strigidae.

Lord Howe boobook Extinct subspecies of bird

The Lord Howe boobook, also known as the Lord Howe morepork, was a bird in the true owl family endemic to Lord Howe Island in the Tasman Sea, part of New South Wales, Australia. It is an extinct and little-known subspecies of the morepork.

Norfolk golden whistler Subspecies of bird

The Norfolk golden whistler, also known as the Norfolk Island whistler or Norfolk Island thickhead, and locally as the “tamey”, is a small bird in the whistler family, Pachycephalidae. It is a subspecies of the Australian golden whistler and endemic to Norfolk Island, an Australian territory in the Tasman Sea, between Australia and New Zealand.

Christmas goshawk Subspecies of bird

The Christmas goshawk or Christmas Island goshawk, is a bird of prey in the goshawk and sparrowhawk family Accipitridae. It is a threatened endemic of Christmas Island, an Australian territory in the eastern Indian Ocean.

The Christmas Island swiftlet, also known as the Christmas glossy swiftlet or the Christmas cave swiftlet, is a small bird in the swift family Apodidae. It is endemic to Christmas Island, an Australian territory in the eastern Indian Ocean. It was formerly commonly treated as a subspecies of the glossy swiftlet.

Northern boobook Species of owl

The northern boobook belongs to the family Strigidae and is a raptorial owl endemic to eastern and southern countries of Asia. The species was considered, until recently, a conspecific of Ninox scutulata or brown boobook, a species of similar distribution encompassing 11 subspecies. The species currently includes two subspecies, the migrant Ninox japonica japonica and the non-migrant Ninox japonica totogo. Despite being considered as the most common breeding owl in Japan, little research has been conducted on the species and subspecies and the taxonomic classification of N.j.togoto and N.j.japonica has been a subject of debate. There are no indications of significant decline in northern boobook populations and therefore, its conservation status has been classified as least concern by the IUCN Red List.

Seram boobook Species of owl

The Seram boobook is a species of owl in the family Strigidae. It is found on the Indonesian islands of Seram, Kelang and Ambon. Its natural habitat is subtropical or tropical moist lowland forests. It is threatened by habitat loss. It used to be considered a subspecies of the Moluccan boobook.

Tanimbar boobook Species of owl

The Tanimbar boobook, or Tanimbar hawk-owl, is a species of owl in the family Strigidae. It is found in the Tanimbar Islands of Indonesia. Its natural habitat is subtropical or tropical moist lowland forests. It is threatened by habitat loss. It used to be considered a subspecies of the Moluccan boobook.

The Mindanao boobook or Mindanao hawk-owl is a species of owl in the family Strigidae that is endemic to the Philippines on the island of Mindanao. It was previously known as a subspecies of the Philippine hawk-owl, but was reclassified in 2012, as voice and other evidence suggested it a distinct species. It is found in tropical moist lowland forest. It is threatened by habitat loss.

The Romblon boobook or Romblon hawk-owl, is a species of owl in the family Strigidae that is endemic to the Philippines only found in the islands of Tablas, Sibuyan and Romblon. It was previously known as a subspecies of the Philippine hawk-owl, but was reclassified in 2012, as voice and other evidence suggested it a distinct species. Its natural habitats are r tropical moist lowland forest. It is threatened by habitat loss.

Ninox boobook ocellata is a subspecies of the Australian boobook, which is also widely known as the southern boobook. The southern boobook is the most common and smallest owl on the Australian mainland.

The Rote boobook is a species of owl in the family Strigidae. It is endemic to Rote Island in the Lesser Sunda Islands of Indonesia.

The Timor boobook is a species of owl in the family Strigidae. It is found on Timor, Roma, Leti and Semau Islands in the eastern Lesser Sunda Islands of Indonesia.

The Tasmanian boobook, also known as the Tasmanian spotted owl, is a species of owl in the family Strigidae. It is native to Tasmania.

References