The sulphur-billed nuthatch (''Sitta oenochlamys'') is a species of

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

in the family

Sittidae The nuthatches () constitute a genus, ''Sitta'', of small passerine birds belonging to the family Sittidae. Characterised by large heads, short tails, and powerful bills and feet, nuthatches advertise their territory using loud, simple songs. Mo ...

. It is

endemic Endemism is the state of a species being found only 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 foun ...

to the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

. Its natural

habitat In ecology, habitat refers to the array of resources, 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 manifestation of its ...

s are

tropical moist lowland forest Tropical and subtropical moist broadleaf forests (TSMF), also known as tropical moist forest, is a subtropical and tropical forest habitat type defined by the World Wide Fund for Nature (WWF). Description TSMF is generally found in large ...

and tropical moist

montane forest Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

. It is commonly found in mixed flocks along with Blue-headed fantails,

sunbirds Sunbirds and spiderhunters make up the family (biology), family Nectariniidae of passerine birds. They are small, slender passerines from the Old World, usually with downward-curved bills. Many are brightly coloured, often with iridescent feathe ...

, flowerpeckers and other small forest birds.

Description and taxonomy

EBird eBird is an online database of bird observations providing scientists, researchers and amateur naturalists with real-time data about bird distribution and abundance. Originally restricted to sightings from the Western Hemisphere, the project e ...

describes the bird as "A small bird of lowland and montane forest and edge. Unmistakable; the only nuthatch in its range. Blue above with a black edge to the wing, a black forehead, a thin black stripe behind the eye, pale pink underparts, and a yellow bill, eye, and eye-ring. Often joins mixed-species flocks. The only woodpecker similar in size is Philippine Woodpecker, but Sulphur-billed Nuthatch is blue rather than brown. Voice includes high-pitched, descending shrieking calls and sharp staccato chips."

Subspecies

Three

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

are recognized: * ''S.o. oenochlamys —'' Found on

Panay Panay is the sixth-largest and fourth-most populous island in the Philippines, with a total land area of and a total population of 4,542,926, as of 2020 census. Panay comprises 4.4 percent of the entire population of the country. The City of Il ...

Guimaras Guimaras (), officially the Province of Guimaras (; ), is an island province in the Philippines located in the Western Visayas region. The capital is Jordan, while the largest local government unit is the municipality of Buenavista. The provin ...

Negros Negros (, , ) is the fourth largest and third most populous island in the Philippines, with a total land area of . The coastal zone of the southern part of Negros is identified as a site of highest marine biodiversity importance in the Coral Tr ...

and

Cebu Cebu ( ; ), officially the Province of Cebu (; ), is a province of the Philippines located in the Central Visayas region, and consists of a main island and 167 surrounding islands and islets. The coastal zone of Cebu is identified as a ...

* ''S.o. mesoleuca —'' Found on Northwest Luzon around the

Cordillera Mountain Range The Cordillera Central or Cordillera Range is a massive mountain range long north–south and east-west situated in the north-central part of the island of Luzon, in the Philippines. The mountain range encompasses all provinces of the Cordil ...

* ''S.o. isarog —'' Found on

Luzon Luzon ( , ) is the largest and most populous List of islands in the Philippines, island in the Philippines. Located in the northern portion of the List of islands of the Philippines, Philippine archipelago, it is the economic and political ce ...

except the Northwest * ''S.o. lilacea —''Found on

Samar Samar ( ) is the third-largest and seventh-most populous island in the Philippines, with a total population of 1,909,537 as of the 2020 census. It is located in the eastern Visayas, which are in the central Philippines. The island is divided in ...

Leyte Leyte ( ) is an island in the Visayas group of islands in the Philippines. It is eighth-largest and sixth-most populous island in the Philippines, with a total population of 2,626,970 as of 2020 census. Since the accessibility of land has been ...

Biliran Biliran, officially the Province of Biliran (Waray language, Waray-Waray: ''Probinsya han Biliran''; ; ), is an island province in the Philippines located in the Eastern Visayas Regions of the Philippines, region (Region VIII). Biliran is one of ...

, * ''S.o. apo —'' Found on

Mindanao Mindanao ( ) is the List of islands of the Philippines, second-largest island in the Philippines, after Luzon, and List of islands by population, seventh-most populous island in the world. Located in the southern region of the archipelago, the ...

except the

Zamboanga Peninsula Zamboanga Peninsula (; ; ) is an administrative region in Mindanao, Philippines, designated as Region IX. It consists of the provinces of Zamboanga del Norte, Zamboanga Sibugay and Zamboanga del Sur, and the cities of Isabela and Zamboang ...

* ''S.o. zamboanga —''Found on

, and

Basilan Basilan, officially the Province of Basilan (; ; ; ), is an island province of the Philippines located primarily in the Bangsamoro Autonomous Region. Basilan Island is the largest and northernmost of the major islands of the Sulu Archipelago ...

Ecology and behavior

Feeds on insects. Found singly, in pairs, in flocks of up to 20 individuals and also joins mixed species flocks. It is very active and forages near the canopy, it is often seen on trunks where its gleans loose bark, moss or epiphytes. Birds collected in breeding condition with enlarged gonads in January to May. Not much else is known.

Habitat and conservation status

Its natural

habitats In ecology, habitat refers to the array of resources, 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 manifestation of its ...

at tropical moist lowland and

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

primary forest An old-growth forest or primary forest is a forest that has developed over a long period of time without Disturbance (ecology), disturbance. Due to this, old-growth forests exhibit unique ecological features. The Food and Agriculture Organizati ...

and

secondary forest A secondary forest (or second-growth forest) is a forest or woodland area which has regenerated through largely natural processes after human-caused Disturbance (ecology), disturbances, such as Logging, timber harvest or agriculture clearing, or ...

up to 2,060 meters above sea level. It is more common in higher elevations. The

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

has assessed this bird as

least-concern species A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

as it is still common throughout its large range. The population is decreasing due to the habitat loss and deforestation in the

. More studies are recommended to better understand this species, population and conservation status.

References

sulphur-billed nuthatch The sulphur-billed nuthatch (''Sitta oenochlamys'') is a species of bird in the family Sittidae. It is Endemism, endemic to the Philippines. Its natural habitats are subtropical or tropical moist lowland forest, tropical moist lowland forest and ...

Endemic birds of the Philippines

Taxonomy articles created by Polbot {{Certhioidea-stub