Kona Grosbeak
Encyclopedia
The Kona Grosbeak is an extinct
species of finch
in the Hawaiian honeycreeper
subfamily
, Drepanidinae. The Kona Grosbeak was endemic to naio (Myoporum sandwicense
) forests on ʻaʻā lava
flows at elevations of 1400–1500 m (4,593.2–4,921.3 ft) near the Kona District
on the island of Hawaii
. The species was already very rare when it was first discovered, being found in only about 10 square kilometre, and was last collected in 1894. Reasons for its extinction are not very well known. The genus is known from fossils from Kauai
, Oahu
and Maui
. It was unknown to the Native Hawaiians, and thus a name for it does not exist in the Hawaiian language
.
. The bird had a large head and a giant, brownish-gray beak
.
, with a large beak
adapted to break through the hard endocarp of dried naio (Myoporum sandwicense
) fruit
s. It may have also taken green naio fruit and leaves, as well as softer fruit such as that of the ieie (Freycinetia arborea
). Young were most likely fed invertebrate
s.
was one of the few people to observe Kona Grosbeaks in the wild. An account of his sightings is featured in The Ibis, which was published in 1893:
The Chloridops kona (Kona grosbeak), though an interesting bird on account of its peculiar structure, is a singularly uninteresting one in its habits. It is a dull, sluggish, solitary bird and very silent-its whole existence may be summed up in the words “to eat.” Its food consists of the seeds of the fruit of the aaka (Myoporum sandwicense
) (bastard sandal-tree, and probably in other seasons of those of the sandalwood tree), and as these are very minute, its whole time seems to be taken up in cracking the extremely hard shells of this fruit, for which its extraordinarily powerful beak and heavy head have been developed. I think there must have been hundreds of the small white kernels in those that I examined. The incessant cracking of the fruits when one of these birds is feeding, the noise of which can be heard for a considerable distance, renders the bird much easier to see than it otherwise would be. It is mostly found on the roughest lava, but also wanders into the open spaces in the forest. I never heard it sing (once mistook the young Rhodacanthis
-Greater Koa Finch
song for that of Chloridops), but my boy informed me that he had heard it once, and its song was not like that of Rhodocanthis. Only once did I see it display any real activity, when a male and female were in active pursuit of one another amongst the sandal-trees. Its beak is nearly always very dirty, with a brown substance adherent to it, which must be derived from the sandal-tree.
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...
species of finch
Finch
The true finches are passerine birds in the family Fringillidae. They are predominantly seed-eating songbirds. Most are native to the Northern Hemisphere, but one subfamily is endemic to the Neotropics, one to the Hawaiian Islands, and one subfamily – monotypic at genus level – is found...
in the Hawaiian honeycreeper
Hawaiian honeycreeper
Hawaiian honeycreepers are small, passerine birds endemic to Hawaii. Some authorities still categorize this group as a family Drepanididae, but in recent years, most authorities consider them a subfamily, Drepanidinae, of Fringillidae, the finch family...
subfamily
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
, Drepanidinae. The Kona Grosbeak was endemic to naio (Myoporum sandwicense
Myoporum sandwicense
Myoporum sandwicense is a species of flowering tree in the figwort family, Scrophulariaceae. Common names include Naio, bastard sandalwood or false sandalwood. It is native to Hawaii and Mangaia in the Cook Islands.-Description:...
) forests on ʻaʻā lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...
flows at elevations of 1400–1500 m (4,593.2–4,921.3 ft) near the Kona District
Kona District, Hawaii
Kona is the name of a moku or district on the Big Island of Hawaii in the State of Hawaii. In the current system of administration of Hawaii County, the moku of Kona is divided into North Kona District and South Kona District . The term "Kona" is sometimes used to refer to its largest town,...
on the island of Hawaii
Hawaii (island)
The Island of Hawaii, also called the Big Island or Hawaii Island , is a volcanic island in the North Pacific Ocean...
. The species was already very rare when it was first discovered, being found in only about 10 square kilometre, and was last collected in 1894. Reasons for its extinction are not very well known. The genus is known from fossils from Kauai
Kauai
Kauai or Kauai, known as Tauai in the ancient Kaua'i dialect, is geologically the oldest of the main Hawaiian Islands. With an area of , it is the fourth largest of the main islands in the Hawaiian archipelago, and the 21st largest island in the United States. Known also as the "Garden Isle",...
, Oahu
Oahu
Oahu or Oahu , known as "The Gathering Place", is the third largest of the Hawaiian Islands and most populous of the islands in the U.S. state of Hawaii. The state capital Honolulu is located on the southeast coast...
and Maui
Maui
The island of Maui is the second-largest of the Hawaiian Islands at and is the 17th largest island in the United States. Maui is part of the state of Hawaii and is the largest of Maui County's four islands, bigger than Lānai, Kahoolawe, and Molokai. In 2010, Maui had a population of 144,444,...
. It was unknown to the Native Hawaiians, and thus a name for it does not exist in the Hawaiian language
Hawaiian language
The Hawaiian language is a Polynesian language that takes its name from Hawaii, the largest island in the tropical North Pacific archipelago where it developed. Hawaiian, along with English, is an official language of the state of Hawaii...
.
Description
The Kona Grosbeak, at 15 centimetres (5.9 in), was a medium sized, chunky bird. Its plumage was a dull olive green, and did not display sexual dimorphismSexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
. The bird had a large head and a giant, brownish-gray beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
.
Diet
The Kona Grosbeak was a frugivoreFrugivore
A frugivore is a fruit eater. It can be any type of herbivore or omnivore where fruit is a preferred food type. Because approximately 20% of all mammalian herbivores also eat fruit, frugivory is considered to be common among mammals. Since frugivores eat a lot of fruit they are highly dependent...
, with a large beak
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
adapted to break through the hard endocarp of dried naio (Myoporum sandwicense
Myoporum sandwicense
Myoporum sandwicense is a species of flowering tree in the figwort family, Scrophulariaceae. Common names include Naio, bastard sandalwood or false sandalwood. It is native to Hawaii and Mangaia in the Cook Islands.-Description:...
) fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
s. It may have also taken green naio fruit and leaves, as well as softer fruit such as that of the ieie (Freycinetia arborea
Freycinetia arborea
The Ieie is a densely branched, brittle, woody climber in the screwpalm family, Pandanaceae that is endemic to the Pacific Islands. Ieie is found in moist forest on the Hawaiian, Marquesas, Austral, Society, and Cook Islands. It grows into the forest canopy, attaching itself to a host tree using...
). Young were most likely fed invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s.
Wilson's Report
The ornithologist Scott Barchard WilsonScott Barchard Wilson
Scott Barchard Wilson was a British ornithologist and explorer.In 1887, Wilson was sent by his professor Alfred Newton to study and collect birds in Hawaii. On his return he wrote Aves Hawaiienses with Arthur Humble Evans, illustrated by Frederick William Frohawk.-References:* Fuller, Errol :...
was one of the few people to observe Kona Grosbeaks in the wild. An account of his sightings is featured in The Ibis, which was published in 1893:
Myoporum sandwicense
Myoporum sandwicense is a species of flowering tree in the figwort family, Scrophulariaceae. Common names include Naio, bastard sandalwood or false sandalwood. It is native to Hawaii and Mangaia in the Cook Islands.-Description:...
) (bastard sandal-tree, and probably in other seasons of those of the sandalwood tree), and as these are very minute, its whole time seems to be taken up in cracking the extremely hard shells of this fruit, for which its extraordinarily powerful beak and heavy head have been developed. I think there must have been hundreds of the small white kernels in those that I examined. The incessant cracking of the fruits when one of these birds is feeding, the noise of which can be heard for a considerable distance, renders the bird much easier to see than it otherwise would be. It is mostly found on the roughest lava, but also wanders into the open spaces in the forest. I never heard it sing (once mistook the young Rhodacanthis
Rhodacanthis
Rhodacanthis is an extinct genus of finches in the Hawaiian honeycreeper subfamily, Drepanidinae. All four species were endemic to the Hawaiian Islands. Members of this genus were granivores, with bills adapted to the seeds and pods of legumes. The two species that became extinct in the 1890s,...
-Greater Koa Finch
Greater Koa Finch
The Greater Koa Finch was a species of finch in the Fringillidae family. It was found only in the Hawaiian Islands. It has been extinct since the late 19th century.- Description :...
song for that of Chloridops), but my boy informed me that he had heard it once, and its song was not like that of Rhodocanthis. Only once did I see it display any real activity, when a male and female were in active pursuit of one another amongst the sandal-trees. Its beak is nearly always very dirty, with a brown substance adherent to it, which must be derived from the sandal-tree.
External links
- 3D view of specimens RMNH 110.015 and RMNH 110.016 at NaturalisNaturalisNaturalis is the national natural history museum of the Netherlands, based in Leiden. It originated from the merger of the Rijksmuseum van Natuurlijke Historie and the Rijksmuseum van Geologie en Mineralogie in 1984. In 1986 it was decided that the museum had to become a public museum and a new...
, Leiden (requires QuickTimeQuickTimeQuickTime is an extensible proprietary multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. The classic version of QuickTime is available for Windows XP and later, as well as Mac OS X Leopard and...
browser plugin).