Lord Howe gerygone

The Lord Howe gerygone or Lord Howe gerygone flyeater (Gerygone insularis) was a small bird in the family Acanthizidae, brown and greyish in color. Its head was brown apart from a pale grey eye-ring and a grey throat and chin, many parts of the animal varied to the colour of yellow, this being apparent in its bright yellow belly. It made its home in the canopies of [2] the island's forest until the early 20th century. The bird has had a variety of monikers: locally, it was known as the "rain-bird" due to its activity after the rains, or the "pop-goes-the-weasel",[3] due to the similarity of its song to the well-known tune.[4] The bird was endemic to Lord Howe Island in the Tasman Sea (part of New South Wales, Australia). There have been no records of the species since 1928, and it is considered to be extinct. Its extinction is almost certainly due to predation by black rats which were accidentally introduced to the island in 1918 following the shipwreck of the SS Makambo there.[5]

Lord Howe gerygone
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Acanthizidae
Genus: Gerygone
Species:
G. insularis
Binomial name
Gerygone insularis
Ramsay, 1879
Synonyms
  • Royigerygone insularis
  • Pseudogerygone insularis

Taxonomy

There is much conflict in scientific literature regarding the exact taxonomic divisions of the gerygone species in the area. Gerygone insularis was previously referred to as Pseudogerygone insularis. There is also a significant mention of a second species, Gerygone thorpe, but, other than a smaller size there is not apparent evidence that this was a separate species.[6] The bird is more widely referred to as the Gerygone insularis as named by Ramsey in 1879.

Gerygone insularis was also considered a subspecies of a broader taxon which included G. modesta from Norfolk Island and G. igata from New Zealand.[7]

Physiology

Appearance

The Lord Howe gerygone was a small brown and grayish perching songbird. The small feathers extending from the bird's eye to its ear were pale grey as well as the section of feathers between its eyes leading to its eyebrows. The Lord Howe gerygone had a ring of feathers around its eye of lighter grey forming a light perimeter around the orbital, which matched the similarly light feathers of its chin and throat. The portion of its body lining the ribcage yet excluding the abdomen had medium brown coloring, with the back of the head leading to the beginning of the tail matching this color scheme. The breast was a shade of pale-grey complemented with a touch of yellow that led to the fully yellow abdomen. The dorsal portion of its tail was a shade of brown gradually turning to black at the tip of the tail. The ventral portion of the tail was all white. The Lord Howe gerygone had pink eyes, similar to those of an albino rat, and a thin grey bill.[8]

Body Size

On average, the Lord Howe gerygone grew to be roughly 12 centimeters and weighing 6 to 7 grams. The small body type is common with perching songbirds. The meaning of gerygone is born of sound. It lived in the canopy of Australian forests and its small body coupled with its thin bill was ideal for feeding on small insects.[9]

Behavior

Reproduction

A pregnant Lord Howe gerygone would lay a clutch of three pink-tinged, brown-speckled eggs in a domed nest made up of dry bark, fibres, leaves, grass, moss and wool wrapped together with a spider web suspended from a twig. The nest was described by natives as having an entrance on the side, and a projecting hood. (Hull, 1909)

Diet

The Lord Howe gerygone's diet consisted mostly of small insects and spiders. The small bill was used to pull these insects out of the trees high up in the forest canopy.[10] They were very abundant after rainfall due to the presence of more small insects during this time. (Hull, 1909)

Habitat

It was endemic to Lord Howe Island, Australia. This species of bird was very common and found mostly in canopies of the native forests and secondary regrowths on this island.[11]

Threats

Extinction

The Lord Howe gerygone has not been seen alive since 1928. It is thought that its extinction was due to the introduction of black rats that preyed on the bird's nests. Also, it is believed that disease introduced by other similar birds were related to the cause of extinction.[12]

Miscellaneous

Though this species is listed by the EBPC as migratory, it was not a migratory species. It is listed this way due to the inclusion of Endangered or Presumed Extinct species when the list was created in 2001.

References
  1. BirdLife International (2012). "Gerygone insularis". IUCN Red List of Threatened Species. 2012. Retrieved 26 November 2013.CS1 maint: ref=harv (link)
  2. Bird Life. Lord Howe Gerygone Gerygone insularis. Access: http://www.birdlife.org/datazone/speciesfactsheet.php?id=5454 Accessed Thurs 24 Oct 2013 9:50:20
  3. Hindwood, p. 68.
  4. Paramonov, S.J.,1960, “Lord Howe Island, a Riddle of the Pacific. Part II” Pacific Science, Vol. 14, Mãnoa, p.77
  5. Garnett & Crowley, p. 477.
  6. Hull, Basset A.F., 1909, "The Bird of Lorde Howe and Norfolk Islands" The proceedings of the Linnean Society of New South Wales, Vol. 34, p.680-682
  7. Avibase-the world bird database, "Grey, Lord Howe or Norfolk Island Gerygone"
  8. Department of the Environment (2013). Gerygone insularis in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Fri, 25 Oct 2013 05:00:42 +1100.
  9. Department of the Environment (2013). Gerygone insularis in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Fri, 25 Oct 2013 05:00:42 +1100.
  10. Department of the Environment (2013). Gerygone insularis in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Fri, 25 Oct 2013 05:00:42 +1100.
  11. Department of the Environment. Gerygone insularis in Species Profile and Threats Database, Department of the Environment, Canberra. Department of the Environment Website
  12. BirdLife International 2012. Gerygone insularis. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. www.iucnredlist.org. Downloaded on 24 October 2013.
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