The puaiohi (''Myadestes palmeri''), or small Kauai thrush, is a rare species of

songbird A songbird is a bird belonging to the suborder Passeri of the perching birds (Passeriformes). Another name that is sometimes seen as the scientific or vernacular name is Oscines, from Latin ''oscen'', "songbird". The Passeriformes contains 500 ...

in the thrush family,

Turdidae The thrushes are a passerine bird family, Turdidae, with a worldwide distribution. The family was once much larger before biologists reclassified the former subfamily Saxicolinae, which includes the chats and European robins, as Old World flycat ...

, that is

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 elsew ...

to the

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 stat ...

an island of

Kauai Kauai, () anglicized as Kauai ( ), is geologically the second-oldest of the main Hawaiian Islands (after Niʻihau). With an area of 562.3 square miles (1,456.4 km2), it is the fourth-largest of these islands and the 21st largest island ...

. It is closely related to the other three endemic Hawaiian thrushes, the kāmao, olomao, and ōmao. It was first collected by Henry Palmer in 1891 at Halemanu around the entrance to the Kōkee State Park.

Description

The plumage is mostly nondescript, with

slaty Slate gray is a gray color with a slight azure tinge that is a representation of the average color of the material slate. As a tertiary color, slate is an equal mix of purple and green pigments. Slaty, referring to this color, is often used ...

-brown upperparts and a light gray breast and belly below. Birds have a black bill and pinkish feet. A white eye ring is also fairly prominent and helps distinguish this bird from the other Hawaiian thrushes. Males and females are highly similar in appearance. Juveniles show a pattern transitioning from a spotted whitish-buff above to a scalloped gray-brown below.Collar, N. J. (2005). Puaiohi (''Myadestes palmeri''). Pp 628-629 in: del Hoyo, J., Elliott, A. & Christie, D. A. eds. (2005). ''Handbook of the Birds of the World.'' Vol. 10. Cuckoo-shrikes to Thrushes. Lynx Edicions, Barcelona.

Distribution and habitat

Historically, this species has always been considered rare, favoring forested ravines above . Puaiohi are restricted to the center and southern parts of the

Alakai Wilderness Preserve ''HST-2'', formerly named USNS ''Puerto Rico'' and ''Alakai'', is a vessel owned by the United States Navy Military Sealift Command. She was originally Hawaii Superferry's first high-speed ferry. The vessel was later chartered by Bay Ferries ...

on the Hawaiian island of

. Seventy-five percent of the breeding population occurs in only of forest.

Diet and behavior

Outside the breeding season, most (82%) of the diet is

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 ...

and

berries A berry is a small, pulpy, and often edible fruit. Typically, berries are juicy, rounded, brightly colored, sweet, sour or tart, and do not have a stone or pit, although many pips or seeds may be present. Common examples are strawberries, raspb ...

, the remainder being

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 pairs ...

s and other

invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...

s. Important food sources include fruits of the native olapa (''

Cheirodendron trigynum ''Cheirodendron trigynum'', also known as ''Ōlapa'' or common cheirodendron, is a species of flowering plant in the ginseng family, Araliaceae, that is endemic to Hawaii. It is a medium-sized tree, reaching a height of and a trunk diameter of ...

''), lapalapa ('' C. platyphyllum''), ōhia ha (''

Syzygium sandwicensis ''Syzygium sandwicense'' is a species of flowering plant in the myrtle family, Myrtaceae, that is endemic to Hawaii. Common names include Ōhia ha, Hā, and Pāihi. It is normally a large tree, reaching a height of and a trunk diameter of , bu ...

'') and kanawao (''

Broussaisia arguta ''Broussaisia arguta'', the kanawao, is a species of perennial flowering plant in the ''Hydrangea'' family, Hydrangeaceae, that is endemic to Hawaii. It is the only species in the monotypic genus ''Broussaisia''. Kanawao is a widespread speci ...

''). In the breeding season, over fifty percent of the diet shifts to invertebrates. The song is varied, consisting of a simple trill to a complex wheezing, and high-pitched squeal described as a squeaking rather resembling a metal wheel needing lubrication. Males sing throughout the year, but do so with increasing frequency as the breeding season approaches, peaking from April to May. Nesting has been recorded from as early as March to as late as mid-September. Nests are built in cavities or ledges of

cliff In geography and geology, a cliff is an area of rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. Cliffs are common on co ...

faces, concealed by

moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...

es and

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 except t ...

s, but tree cavities are also used.Snetsinger et al. (1999). Puaiohi (''Myadestes palmeri''). In ''The Birds of North America'', No. 461 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA. Females are the sole nest builders, and nest building can take up to seven days. Females also incubate the eggs and broods and feeds the nestlings. Eggs (usually two per clutch) are grayish-green to greenish-blue with irregular reddish-brown splotches. Eggs hatch after 13–15 days. After fledging, the male becomes the primary food provider to the young, while the female attempts a second brood. Females will also attempt to renest if the first attempt fails.

Status and protection

According to recent data, population estimates range from 414 to 580 birds, and have remained somewhat stable since 1973, although a study published in 1986 estimated a population of approximately 100-125 birds. Puaiohi populations are vulnerable to

drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

hurricanes A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depend ...

, and mammalian predation of both eggs and young.

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 vector i ...

also affects many birds, but a few birds have shown some resistance. (C. Atkinson, USGS, unpublished data). Feral pigs and goats also negatively affect populations of birds by degrading habitat, as has competition from many

invasive plants An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

and animals. The puaiohi was added to the United States Federal Endangered Species List on March 11, 1967. In 1995, a captive breeding program was established. Some birds from this program were being taken back to the

Alakai ''HST-2'', formerly named USNS ''Puerto Rico'' and ''Alakai'', is a vessel owned by the United States Navy Military Sealift Command. She was originally Hawaii Superferry's first high-speed ferry. The vessel was later chartered by Bay Ferries, B ...

to supplement the wild population, though this program has been liquidated and released after

inbreeding depression Inbreeding depression is the reduced biological fitness which has the potential to result from inbreeding (the breeding of related individuals). Biological fitness refers to an organism's ability to survive and perpetuate its genetic material. In ...

was observed in the captive population.

References

External links

Audubon Watchlist Species Account

{{Taxonbar, from=Q2668284 Myadestes Endemic birds of Hawaii Biota of Kauai Critically endangered fauna of Hawaii Birds described in 1893 Taxa named by Walter Rothschild ESA endangered species