Lanai hookbeak

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Lanai hookbeak
Dysmorodrepanis.svg

Lanai hooked bill ( Dysmorodrepanis munroi )

Systematics
Subordination : Songbirds (passeri)
Family : Finches (Fringillidae)
Subfamily : Goldfinches (Carduelinae)
Tribe : Clothes birds (Drepanidini)
Genre : Dysmorodrepanis
Type : Lanai hookbeak
Scientific name of the  genus
Dysmorodrepanis
Perkins , 1919
Scientific name of the  species
Dysmorodrepanis munroi
Perkins, 1919

The lanai hooked beak ( Dysmorodrepanis munroi ), also known as the lanai dresser bird, is an extinct species of songbird from the subfamily of the clothes bird . The species was discovered by George Campbell Munro on the Hawaiian island of Lānaʻi in 1913 , but its taxonomic status remained unclear until 1989.

features

The only known bellows kept in the Bernice P. Bishop Museum in Honolulu is 152 mm in length. James Cowan Greenway suspected that the specimen was partially albino. However, this did not seem to have been the case, although some specimens of the yellow-headed honeydew bird ( Psittirostra psittacea ) on Lānaʻi showed this tendency. In contrast to the yellow-headed hawk bird, the lanai hooked beak is tinted yellow on the reins and above the eyes. The top is light greenish olive. The underside is whitish yellow. At the under tail-coverts the color changes into whitish. The stripe above the eyes is light yellow. White wing fields are formed from the broad tips and inner flags of the arm wings. The upper and lower beak are curved towards each other, so the tip of the lower beak is the only part that touches the upper beak, leaving an opening that makes the beak look like a pair of tweezers.

habitat

All recorded observations are from the forests at the southwest end of Lānaʻis, particularly in the Kaiholena Valley and Waiakeakua. This evidence was at altitudes between 600 and 800 m. However, the lanai hookbeak's habitat in the past covered thousands of acres on Lānaʻi, and it is likely that this species once had a much wider range on this island. The lanai hookbeak was a resident bird. It is believed that he inhabited the montane dry forests, which are dominated by ʻakoko ( Euphorbia lorifolia ) and ōpuhe ( Urera glabra ). The unique shape of the beak, particularly when compared to that of the yellow-headed honeycreeper, and its apparent rarity, suggests that the lanai hooked beak was an extreme specialist and restricted to this habitat.

Way of life

All that is known about feeding behavior is that the lanai hooked beak fed on the fruits of the ōpuhe. It is also believed that the fruits of the ʻakoko enriched the food supply due to their similarity in size and shape with the ōpuhe. However, it is considered unlikely that this species was a pure fruit eater. Rather, it is suggested that the lanai hookbeak specialized in snail catching because of its unique beak. This species was very active in foraging and kept flying from tree to tree. Based on the structure of the beak, it is believed that it was used as a pair of tongs to pluck fruits and flowers for consumption. It is also possible that the bird was able to crush snail shells with its beak and extract the meat from the shell with its primitive and non-tubular tongue. Nothing is known about its breeding behavior. However, it is believed that this species laid two to three eggs, similar to other honeycreeper species, and that the young birds were nestling .

die out

After the holotype was found in 1913, Munro was able to detect this species twice. In March 1916, he heard three copies singing, and he was able to watch one of them. Munro managed one last sighting in August 1918. Between 1900 and 1940 almost the entire forest area of ​​Lānaʻis was converted into pineapple fields. This has dramatically reduced the lanai hookbeak's habitat, and it is believed that this may have played the most important role in this species becoming extinct. It is also believed that the bird malaria that attacked the avifauna Lānaʻis since the 1920s could also have been a cause of extinction. Other reasons for the disappearance of the Lanai hookbeak could have been the spread of rats and feral cats as well as the extinction of endemic snail species on Lānaʻi through human intervention. In 1988 the species was added to the IUCN's list of extinct bird species.

Systematics

In February 1913, George Campbell Munro discovered a new bird species in the Kaiholena Valley on Lānaʻi, the status of which remained a mystery for a long time. In 1919 the ornithologist Robert Cyril Layton Perkins wrote the first scientific description, which was not recognized in official ornithological circles. In 1939, James Cowan Greenway argued that the Lanai Hook Shawl must be an anomalous specimen of the yellow-headed honeycreeper. He suspected that the specimen was a young male or probably a hybrid. The main distinguishing feature of the Lanai hooked bill is its beak, with the lower bill curved and only touching the upper bill at the tip. Greenway also argued that the shape of the beak was due to a defect, an accident or a mutation and that deformed specimens were discovered in the population of the now also presumably extinct yellow-headed honeydew bird on Lānaʻi. Greenway further emphasized that Munro could not catch another specimen, despite eager searches. In 1989, the paleo-ornithologists Helen Frances James , Richard Zusi and Storrs L. Olson examined the specimen again. The skull was removed from the follicle and based on the skull osteology it could be proven that there were no deformities and that the skull and the lower jaw also showed modifications that correspond to the unusual shape of the beak. The authenticity of this taxon was thus established on the basis of this analysis.

etymology

The lanai hookbill is the only species in the genus Dysmorodrepanis . The generic name is derived from the ancient Greek term "dusmoros" and means "deformed". The word "drepanis" identifies the lanai hooked beak as a clothes bird. It comes from ancient Greek, means sickle and is a reference to the sickle-shaped beaks of the honeymoon birds. The species epithet munroi honors the botanist and ornithologist George Campbell Munro , who discovered the species.

literature

  • Thomas J. Snetsinger, Michelle H. Reynolds, Christina M. Herrman: ' Ō ' ¾ ( Psittirostra psittacea ) and Lana ' i Hookbill ( Dysmorodrepanis munroi ) . In: Alan F. Poole , Frank B. Gill (Eds.): The Birds of North America . Volumes 335–336. The Birds of North America, Inc., Philadelphia, PA 1998 ( bna.birds.cornell.edu [accessed January 8, 2013]).
  • Julian P. Hume , Michael P. Walters : Extinct Birds . 1st edition. T & AD Poyser, London 2012, ISBN 978-1-4081-5725-1 , Fringillidae, pp. 291-292 .

Individual evidence

  1. ↑ a b J. C. Greenway: Dysmorodrepanis munroi probably not a valid form. In: The Auk. 56, 1939, pp. 479-480.
  2. ↑ Snetsinger 1998, p. 4.
  3. ↑ a b c d e Snetsinger 1998, p. 5.
  4. ↑ Thomas J. Snetsinger, Michelle H. Reynolds, Christina M. Herrmann: Kona Grosbeak . In: The Birds of North America Online . Cornell Lab of Ornithology. 1998. Retrieved January 8, 2013.
  5. ↑ a b Snetsinger 1998, p. 2.
  6. ↑ a b Snetsinger 1998, p. 6.
  7. ↑ Snetsinger 1998, p. 3.
  8. ↑ a b Snetsinger 1998, p. 10.
  9. ^ GC Munro: Birds of Hawai'i. Tongg Publishing Company, Honolulu 1944.
  10. ↑ Snetsinger 1998, p. 13.
  11. ↑ a b Snetsinger 1998, p. 11.
  12. ↑ a b H. F. James, RL Zusi, SL Olson: Dysmorodrepanis munroi (Fringillidae: Drepanidini), a valid genus and species of Hawaiian Finch. Wilson Bulletin 101, 1989, pp. 159-179.
  13. ↑ a b Snetsinger 1998, p. 15.

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