Gallirallus

Gallirallus
Weka, Gallirallus australis
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Gruiformes
Family: Rallidae
Genus: Gallirallus
Lafresnaye, 1841
Species

11-12 living, several recently extinct, and see text

Synonyms
  • Tricholimnas
  • Hypotaenidia

Gallirallus is a genus that contains about a dozen living, and several recently extinct, species of rails that live in the Australasian-Pacific region. The genus is characterised by an ability to colonise relatively small and isolated islands and thereafter to evolve flightless forms, many of which became extinct following Polynesian settlement.

Description

Buff-banded rail

Many of the rails, including the well-known weka of New Zealand, are flightless or nearly so; others, such as the buff-banded rail, can travel for considerable distances once airborne even though they are not great flyers. This has enabled the flying species of this genus to colonize islands all over the region.

Many of the resultant flightless island endemics became extinct after the arrival of humans, which hunted these birds for food, introduced novel predators like rats, dogs or pigs, and upset the local ecosystems. A common Polynesian name of these rails, mainly relatives of G. philippensis, is veka/weka (in English, this name is generally limited to Gallirallus australis).

One species, the Guam rail, is extinct in the wild; there exists a semi-wild population in preparation for reintroduction to its original habitat. Three more species have gone extinct in historic times, while the New Caledonian rail probably is extinct. The Sharpe's rail, only known from the type specimen of unclear origin, may also be extinct, although recent evidence suggests that it is invalid, and instead should be regarded as a morph of the buff-banded rail.[1] Two further species are assumed from circumstantial evidence to have survived into the Modern era but are not known from recent specimens.

On the other hand, Gallirallus species are (with the exception of the weka) notoriously retiring and shy birds with often drab coloration. Given that the Okinawa rail and the Calayan rail have only been discovered in the late 20th century and as late as 2004, respectively, it cannot be ruled out that the New Caledonian and Sharpe's rail may still exist.

Living and recently extinct species

Contemporary drawing of the extinct Norfolk Island rail

These species are placed by BirdLife International and IUCN in separate genus Hypotaenidia

Species extinct before 1500 AD

Illustration of an unidentified extinct species (possibly G. vekamatolu) from Vava'u, 1739

References

Notes

  1. 1 2 BirdLife International Globally Threatened Forums, 2008
  2. 1 2 3 Kirchman, Jeremy J.; Steadman, David. (2007). "New species of extinct rails (Aves: Rallidae) from archaeological sites in the Marquesas Islands, French Polynesia.". Pacific Science. 61 (1): 145–163. doi:10.1353/psc.2007.0008.(subscription required)
  3. ↑ "Gallirallus huiatua; holotype". Collections Online. Museum of New Zealand Te Papa Tongarewa. Retrieved 16 July 2010.
  4. ↑ Steadman, David W.; Worthy, Trevor H.; Anderson, Atholl J.; Walter, Richard. (2000-06-01). "New species and records of birds from prehistoric sites on Niue, southwest Pacific.". Wilson Bulletin. 112 (2): 165–186. doi:10.1676/0043-5643(2000)112[0165:NSAROB]2.0.CO;2.(subscription required)
  5. ↑ Steadman, D. W. (1986). "Two new species of rails (Aves: Rallidae) from Mangaia, Southern Cook Islands.". Pacific Science. 40 (1): 27–43.
  6. ↑ Worthy, Trevor H.; Bollt, Robert. (2011-01-01). "Prehistoric birds and bats from the Atiahara site, Tubuai, Austral Islands, East Polynesia.". Pacific Science. 65 (1): 69–86. doi:10.2984/65.1.069.(subscription required)
  7. ↑ A similar bird was found to live on nearby Vava‘u in 1793. Given that G. vekamatolu was flightless, this may just as well represent a related species.
  8. ↑ Kirchman, J.J.; Steadman, D. W. (2005). "Rails (Aves: Rallidae: Gallirallus) from prehistoric sites in the Kingdom of Tonga, including description of a new species.". Proceedings of the Biological Society of Washington. 118: 465–477. doi:10.2988/0006-324x(2005)118[465:rargfp]2.0.co;2.

Sources

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