Laysan Finch
Encyclopedia
The Laysan Finch is a species of finch
in the Hawaiian honeycreeper
subfamily
, Drepanidinae, that is endemic to the Northwestern Hawaiian Islands
. It is one of four remaining finch-billed Hawaiian honeycreepers, and is closely related to the smaller Nihoa Finch
. The Laysan Finch is named for Laysan
, the island to which it was endemic on its discovery. It was subsequently introduced to a few other atoll
s, and its historical range included some of the main islands
.
with a whitish belly and a grey neck. The female is duller than the male, with brown streaking. It is almost impossible to confuse the Laysan Finch with any other bird in the field as it is the only passerine
species found on the few islands it lives on.
, along with the Laysan Rail
(Porzana palmeri), the Laysan Apapane (Himatione sanguinea freethi), the Laysan Duck
(Anas laysanensis), and the Laysan Millerbird
(Acrocephalus familiaris familiaris). Populations were introduced to several islands, including Pearl and Hermes Atoll
, where the species persists, and Midway Atoll
, where it survived until the introduction of rat
s. The fossil
record shows that the finch once had a greater range in Hawaii, reaching as far as Oahu
, and that birds on Laysan represent a relict
population.
after three weeks, and are cared for by the parents for another three weeks.
The Laysan Finch is a generalist
, feeding on seed
s, small insect
s, fruit
, carrion
(of seabird
s and Hawaiian Monk Seal
s), and the eggs
of nesting seabirds. While unable to break into the eggs of the larger seabirds (such as albatross
and boobies
) they will scavenge from them. They actively take the eggs of smaller seabirds such as those of White Tern
(Gygis alba) and the endemic Laysan Duck
(Anas laysanensis).
of domestic rabbit
s (unlike the Laysan Millerbird
, Apapane and rail
) by taking carrion
and seabird
eggs
. Laysan is now part of the Hawaiian Islands National Wildlife Refuge.
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, that is endemic to the Northwestern Hawaiian Islands
Northwestern Hawaiian Islands
The Northwestern Hawaiian Islands or the Leeward Islands are the small islands and atolls in the Hawaiian island chain located northwest of the islands of Kauai and Niihau. They are administered by the U.S. state of Hawaii except Midway Atoll, which has temporary residential facilities and is...
. It is one of four remaining finch-billed Hawaiian honeycreepers, and is closely related to the smaller Nihoa Finch
Nihoa Finch
The Nihoa Finch is one of the two endemic bird species of the tiny Hawaiian island Nihoa, the other being the Nihoa Millerbird. When it was classified in 1917, scientists thought that it would be the last endemic species named. This was later found untrue. The island's population is 1000-3000 birds...
. The Laysan Finch is named for Laysan
Laysan
Laysan , located northwest of Honolulu at N25° 42' 14" W171° 44' 04", is one of the Northwestern Hawaiian Islands. It comprises one land mass of , about 1 by 1.5 miles in size . It is an atoll of sorts, although the land completely surrounds a shallow central lake some above sea level that has...
, the island to which it was endemic on its discovery. It was subsequently introduced to a few other atoll
Atoll
An atoll is a coral island that encircles a lagoon partially or completely.- Usage :The word atoll comes from the Dhivehi word atholhu OED...
s, and its historical range included some of the main islands
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
.
Description
The Laysan Finch is a large honeycreeper with a heavy bill. Overall the male has yellow plumagePlumage
Plumage refers both to the layer of feathers that cover a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage vary between species and subspecies and can also vary between different age classes, sexes, and season. Within species there can also be a...
with a whitish belly and a grey neck. The female is duller than the male, with brown streaking. It is almost impossible to confuse the Laysan Finch with any other bird in the field as it is the only passerine
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
species found on the few islands it lives on.
Range
On its discovery the Laysan Finch was an endemic resident of the small island of LaysanLaysan
Laysan , located northwest of Honolulu at N25° 42' 14" W171° 44' 04", is one of the Northwestern Hawaiian Islands. It comprises one land mass of , about 1 by 1.5 miles in size . It is an atoll of sorts, although the land completely surrounds a shallow central lake some above sea level that has...
, along with the Laysan Rail
Laysan Rail
The Laysan Rail or Laysan Crake was a tiny inhabitant of the Northwest Hawaiian Island of Laysan. This small island was and still is an important seabird colony, and sustained a number of endemic species, including the rail. It became extinct due to habitat loss by domestic rabbits, and ultimately...
(Porzana palmeri), the Laysan Apapane (Himatione sanguinea freethi), the Laysan Duck
Laysan Duck
The Laysan Duck , also known as the Laysan Teal because of its small size, is an endangered dabbling duck endemic to the Hawaiian Islands...
(Anas laysanensis), and the Laysan Millerbird
Laysan Millerbird
The Laysan Millerbird was a subspecies of the Millerbird, similar in appearance to the remaining subspecies, the Nihoa Millerbird. Its dorsal side was brown, and its belly was grayish...
(Acrocephalus familiaris familiaris). Populations were introduced to several islands, including Pearl and Hermes Atoll
Pearl and Hermes Atoll
The Pearl and Hermes Atoll , is part of the Northwestern Hawaiian Islands. Named after two English whaleships, the Pearl and the Hermes, that wrecked there in 1822, a few, small, sandy islands exist, contained within a lagoon and surrounded by a coral reef. These islands are devoid of vegetation,...
, where the species persists, and Midway Atoll
Midway Atoll
Midway Atoll is a atoll in the North Pacific Ocean, near the northwestern end of the Hawaiian archipelago, about one-third of the way between Honolulu, Hawaii, and Tokyo, Japan. Unique among the Hawaiian islands, Midway observes UTC-11 , eleven hours behind Coordinated Universal Time and one hour...
, where it survived until the introduction of rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s. The fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
record shows that the finch once had a greater range in Hawaii, reaching as far as 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 that birds on Laysan represent a relict
Relict
A relict is a surviving remnant of a natural phenomenon.* In biology a relict is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas....
population.
Behavior
The Laysan Finch nests in vegetation, laying three eggs in a cup-shaped nest. These are incubated for 16 days by the female, the male in turn feeding the female. The chicks fledgeFledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
after three weeks, and are cared for by the parents for another three weeks.
The Laysan Finch is a generalist
Generalist and specialist species
A generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources . A specialist species can only thrive in a narrow range of environmental conditions or has a limited diet. Most organisms do not all fit neatly into either...
, feeding on seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s, small insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, 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,...
, carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
(of seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
s and Hawaiian Monk Seal
Hawaiian Monk Seal
The Hawaiian monk seal, Monachus schauinslandi, is an endangered species of earless seal in the Phocidae family that is endemic to the Hawaiian Islands....
s), and the eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
of nesting seabirds. While unable to break into the eggs of the larger seabirds (such as albatross
Albatross
Albatrosses, of the biological family Diomedeidae, are large seabirds allied to the procellariids, storm-petrels and diving-petrels in the order Procellariiformes . They range widely in the Southern Ocean and the North Pacific...
and boobies
Booby
A booby is a seabird in the genus Sula, part of the Sulidae family. Boobies are closely related to the gannets , which were formerly included in Sula.-Description:...
) they will scavenge from them. They actively take the eggs of smaller seabirds such as those of White Tern
White Tern
The White Tern is a small seabird found across the tropical oceans of the world. It is sometimes known as the Fairy Tern although this name is potentially confusing as it is the common name of the Fairy Tern Sternula nereis...
(Gygis alba) and the endemic Laysan Duck
Laysan Duck
The Laysan Duck , also known as the Laysan Teal because of its small size, is an endangered dabbling duck endemic to the Hawaiian Islands...
(Anas laysanensis).
Conservation
The Laysan Finch is listed as Vulnerable by the IUCN because of its highly restricted range and vulnerability to extremes of weather (it is considered endangered by the State of Hawaii and U.S. government). It survived the devastating effects of the introductionIntroduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
of domestic rabbit
Domestic rabbit
A domestic rabbit, or more commonly known as simply the rabbit, is any of the several varieties of European rabbit that have been domesticated....
s (unlike the Laysan Millerbird
Laysan Millerbird
The Laysan Millerbird was a subspecies of the Millerbird, similar in appearance to the remaining subspecies, the Nihoa Millerbird. Its dorsal side was brown, and its belly was grayish...
, Apapane and rail
Laysan Rail
The Laysan Rail or Laysan Crake was a tiny inhabitant of the Northwest Hawaiian Island of Laysan. This small island was and still is an important seabird colony, and sustained a number of endemic species, including the rail. It became extinct due to habitat loss by domestic rabbits, and ultimately...
) by taking carrion
Carrion
Carrion refers to the carcass of a dead animal. Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters include vultures, hawks, eagles, hyenas, Virginia Opossum, Tasmanian Devils, coyotes, Komodo dragons, and burying beetles...
and seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
eggs
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
. Laysan is now part of the Hawaiian Islands National Wildlife Refuge.