The Maui parrotbill or kiwikiu (''Pseudonestor xanthophrys'') is a species of
Hawaiian honeycreeper
Hawaiian honeycreepers are a group of small, passerine birds endemic to Hawaii. They are closely related to the rosefinches in the genus ''Carpodacus'', but many species have evolved features unlike those present in any other finch. Their great ...
endemic
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...
to the island of
Maui in
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...
. It can only be found in of
mesic and
wet forests at on the windward slopes of
Haleakalā
Haleakalā (; Hawaiian: ), or the East Maui Volcano, is a massive shield volcano that forms more than 75% of the Hawaiian Island of Maui. The western 25% of the island is formed by another volcano, Mauna Kahalawai, also referred to as the West ...
. This species is
critically endangered, with an estimated population in 2016 of 250-540 individuals, but more recent estimates of less than 150 individuals.
Fossil evidence indicates that the bird could at one time be seen in
dry forests
The tropical and subtropical dry broadleaf forest is a habitat type defined by the World Wide Fund for Nature and is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive ...
at elevations as low as , as well as on the island of
Molokai.
Description
![Pseudonestor xanthophrys AvesHawaiienses00Wils 0190](https://upload.wikimedia.org/wikipedia/commons/a/aa/Pseudonestor_xanthophrys_AvesHawaiienses00Wils_0190.jpg)
The Maui parrotbill is one of the larger
Hawaiian honeycreeper
Hawaiian honeycreepers are a group of small, passerine birds endemic to Hawaii. They are closely related to the rosefinches in the genus ''Carpodacus'', but many species have evolved features unlike those present in any other finch. Their great ...
s, measuring
and with a mass of . The bird is yellow on the breast, cheeks, and belly, olive-green on the wings, crown, tail, and back, and has a bright yellow
supercilium. The upper
mandible
In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...
of the bird's
beak
The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for foo ...
is hooked and dark gray, while the lower mandible is chisel-like and pale ivory. Males are longer-winged, larger-billed, and heavier than females. Juveniles are gray-green above and light gray ventrally.
Song
Its call is a short “chip”, which is similar to the
Maui Nui alauahio, chirped every three to five seconds. It song consists of “cheer” notes that are slower and richer than the
ākepa. It also has a short song that sounds like “cheer-wee”.
Diet
The Maui parrotbill is an
insectivore. It uses its large beak and powerful jaw muscles to remove
bark and wood from small
tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
s and
shrubs such as ''ākala'' (''
Rubus hawaiensis
''Rubus hawaiensis'', also called the ''Ākala'', is one of two species (with '' R. macraei'') commonly known as Hawaiian raspberry, endemic to Hawaii. It is found on the islands of Kauai, Molokai, Maui, O'ahu, and Hawaii in mesic to wet for ...
''), ''kanawao'' (''
Broussaisia arguta''), and ''ōhia lehua'' (''
Metrosideros polymorpha
''Metrosideros polymorpha'', the ''ōhia lehua'', is a species of flowering evergreen tree in the myrtle family, Myrtaceae, that is endemic to the six largest islands of Hawaii. It is a highly variable tree, being tall in favorable situations ...
''), eating the
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...
s underneath. The Maui parrotbill also bites open
fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering.
Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...
s in search of insects. It is fond of
moth
Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...
pupae and
beetle
Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
larvae. Pairs of birds forage in a territory of , which they must defend from competing parrotbills.
Breeding
The Maui parrotbill is
monogamous and breeds between November and June. Females build a cup-shaped nest out of ''
Usnea
''Usnea'' is a genus of mostly pale grayish-green fruticose lichens that grow like leafless mini-shrubs or tassels anchored on bark or twigs.Field Guide to California Lichens, Stephen Sharnoff, Yale University Press, 2014, The genus is in the f ...
''
lichens and ''pūkiawe'' (''
Styphelia tameiameiae'') twigs, placing it above the forest floor. Pairs raise a single nestling per season. The female incubates it for 16 days. Fledglings remain with their parents for five to eight months as they learn how to forage.
Habitat and Distribution
The Maui parrotbill currently lives only in undisturbed
wet forests dominated by ''ōhia lehua'' (''
Metrosideros polymorpha
''Metrosideros polymorpha'', the ''ōhia lehua'', is a species of flowering evergreen tree in the myrtle family, Myrtaceae, that is endemic to the six largest islands of Hawaii. It is a highly variable tree, being tall in favorable situations ...
'') and small patches of ''ōhia''-''koa'' (''
Acacia koa
''Acacia koa'' or commonly known as koa is a species of flowering tree in the family Fabaceae. It is endemic to the Hawaiian Islands, where it is the second most common tree. The highest populations are on Hawaii, Maui and Oahu.
Name
The name ...
'')
mesic forest. Its habitat exhibits a dense understory of small
tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
s,
shrubs,
epiphytes,
fern
A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes exce ...
s, and
sedge
The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus '' Carex'' ...
s,
centered between Puu Alaea, Kuhiwa Valley,
Lake Waianapanapa, and upper
Kīpahulu Valley, an area less than , at elevations of .
Hawaiian name
As far as anyone can determine, ''Pseudonestor xanthophrys'' had not historically had a common name in the Hawaiian language. The Hawaiian name ''kiwikiu'' was developed by the Hawaiian Lexicon Committee, who was contacted by the Maui Forest Bird Recovery Project to select an appropriate name. A naming ceremony was held in the bird's habitat in September 2010. The "kiwi" part of the name means bent or curved (e.g., sickle-shaped), which refers to the shape of the bill of this bird. "Kiu" has a double meaning, referring both to the bird's secretive ways and to a cold, chilly wind, such as the breezes in the bird's habitat.
Conservation
The Maui parrotbill's natural
habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
is
mesic and
wet forests. It is threatened by
habitat loss
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...
. Much of the land in the parrotbill's historic range was changed for agricultural purposes, timber production and animal grazing. Introduced pests, such as mosquitoes, rats, and feral ungulates directly and indirectly affect the parrotbill's survival. Mosquitoes spread
avian malaria
Avian malaria is a parasitic disease of birds, caused by parasite species belonging to the genera '' Plasmodium'' and '' Hemoproteus'' (phylum Apicomplexa, class Haemosporidia, family Plasmoiidae). The disease is transmitted by a dipteran vecto ...
, which the parrotbill is susceptible to, rats prey upon the birds' eggs and young, and feral pigs uproot the low-lying vegetation that the parrotbill forages in. Pigs additionally create wallows, which serve as breeding grounds for avian malaria-infected mosquitoes.
The Maui parrotbill was listed as an endangered species in 1967 under the
Endangered Species Act. It is also part of the Maui-Molokai Bird Recovery Plan in 1984, which led to fencing areas of East Maui and removing feral ungulates. The recovery plan also included a captive breeding program, which produced its first chick in 2003. Field research is primarily done by th
Maui Forest Bird Recovery Project
A 2009 survey of the Waikamoi Preserve estimated that there were about 20 birds per square kilometer in the windward preserve near the summit of Haleakala, indicating that the population was holding steady or possibly increasing. A contributing factor is that native shrub cover in Waikamoi has tripled in the past 15 years. A previous study found about half the density. The preserve contains about 25 percent of the population, while most of the rest is in the Hanawi Natural Area Reserve. The birds were once found throughout Maui and Molokai. However, more recent studies have found that the population in fact dramatically declined after 2001, as
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...
has made more of the higher-elevation forests that the kiwikiu inhabits more hospitable to mosquitoes. A translocation effort to a restored area on the
leeward slopes of
Haleakalā
Haleakalā (; Hawaiian: ), or the East Maui Volcano, is a massive shield volcano that forms more than 75% of the Hawaiian Island of Maui. The western 25% of the island is formed by another volcano, Mauna Kahalawai, also referred to as the West ...
in 2019 failed after most birds succumbed to avian malaria, despite otherwise doing well in the habitat.
It has been predicted that if the mosquito population continues increasing, Maui parrotbills may face
functional extinction
Functional extinction is the extinction of a species or other taxon such that:
#It disappears from the fossil record, or historic reports of its existence cease;
#The reduced population no longer plays a significant role in ecosystem function; or ...
in the wild
''In The Wild'' is a popular nature television series produced by the Australian Broadcasting Corporation from 1976 until 1981. It was hosted by Harry Butler, a noted Australian naturalist and environmental consultant.
The re-runs of ''In The ...
by 2027. Due to this, there have been several conservation efforts planned by the Maui Forest Bird Working Group, including at least temporarily fostering a sizeable captive population on zoos in the
mainland United States
The contiguous United States (officially the conterminous United States) consists of the 48 adjoining U.S. states and the Federal District of the United States of America. The term excludes the only two non-contiguous states, Alaska and Hawaii ...
(previous ex-situ conservation efforts were limited to only Hawaii), including potentially the
National Aviary
The National Aviary, located in Pittsburgh, Pennsylvania, is the only independent indoor nonprofit aviary in the United States. It is also the country's largest aviary, and the only one accorded honorary "National" status by the United States Co ...
in
Pennsylvania
Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
,
Smithsonian Conservation Biology Institute in
Virginia
Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...
and the
Tracy Aviary in
Utah
Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...
, potentially introduce a wild population to the
island of Hawaii
Hawaii ( ; haw, Hawaii ) is the largest island in the United States, located in the state of Hawaii. It is the southeasternmost of the Hawaiian Islands, a chain of volcanic islands in the North Pacific Ocean. With an area of , it has 63% of th ...
as a backup, manage and restore more habitat in Maui for eventual release, develop predator control tools, and perform landscape-scale
mosquito control
Mosquito control manages the population of mosquitoes to reduce their damage to human health, economies, and enjoyment. Mosquito control is a vital public-health practice throughout the world and especially in the tropics because mosquitoes spr ...
in the bird's native habitat.
The captive population will consist of 15 male and 15 female wild birds; removing such a large number of birds from an already-small wild population may accelerate the timeline of the species' possible extinction in the wild, but it can allow for a safe population to be bred in captivity away from avian malaria.
References
External links
BirdLife Species Factsheet.*
Maui Parrotbill videos, photos and soundson the Internet Bird Collection
{{Taxonbar, from=Q1092092
Maui parrotbill
Hawaiian honeycreepers
Biota of Maui
Endemic birds of Hawaii
Critically endangered fauna of Hawaii
Maui parrotbill
Taxonomy articles created by Polbot
ESA endangered species