The rusty-breasted nunlet (''Nonnula rubecula'') is a species of

near-passerine Near passerines and higher land-bird assemblage are terms of traditional, pre-cladistic taxonomy that have often been given to tree-dwelling birds or those most often believed to be related to the true passerines (order Passeriformes) owing to mor ...

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

Bucconidae The puffbirds and their relatives in the family Bucconidae are tropical tree-dwelling insectivorous birds that are found from South America up to Mexico. Together with their closest relatives, the jacamars, they form a divergent lineage within th ...

, the puffbirds, nunlets, and nunbirds. It is found in

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

Guyana Guyana, officially the Co-operative Republic of Guyana, is a country on the northern coast of South America, part of the historic British West Indies. entry "Guyana" Georgetown, Guyana, Georgetown is the capital of Guyana and is also the co ...

Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

Suriname Suriname, officially the Republic of Suriname, is a country in northern South America, also considered as part of the Caribbean and the West Indies. It is a developing country with a Human Development Index, high level of human development; i ...

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

, and possibly

French Guiana French Guiana, or Guyane in French, is an Overseas departments and regions of France, overseas department and region of France located on the northern coast of South America in the Guianas and the West Indies. Bordered by Suriname to the west ...

.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, A. Jaramillo, D. F. Lane, J. F. Pacheco, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 24 August 2021. Species Lists of Birds for South American Countries and Territories. https://www.museum.lsu.edu/~Remsen/SACCCountryLists.htm retrieved August 24, 2021

Taxonomy and systematics

Taxonomists recognize the seven subspecies of rusty-breasted nunlet listed below.Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, J. A. Gerbracht, D. Lepage, B. L. Sullivan, and C. L. Wood. 2021. The eBird/Clements checklist of Birds of the World: v2021. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ Retrieved August 25, 2021HBW and BirdLife International (2020) ''Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world'' Version 5. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v5_Dec20.zip xls zipped 1 MBretrieved May 27, 2021 However, the species' taxonomy is unsettled. Some of the subspecies might be species in their own right, some might not be valid at all as separate taxa, and the nominate subspecies might actually represent two subspecies or species.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, A. Jaramillo, D. F. Lane, J. F. Pacheco, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 24 August 2021. A classification of the bird species of South America. American Ornithological Society. https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm retrieved August 24, 2021Rasmussen, P. C., N. Collar, and G. M. Kirwan (2020). Rusty-breasted Nunlet (''Nonnula rubecula''), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.rubnun1.01 retrieved November 10, 2021 *''N. r. tapanahoniensis'' Mees (1968) *''N. r. duidae'' Chapman (1914) *''N. r. interfluvialis''

Parkes Parkes may refer to: * Sir Henry Parkes (1815–1896), Australian politician, one of the earliest and most prominent advocates for Australian federation Named for Henry Parkes * Parkes, New South Wales, a regional town * Parkes Observatory, a radi ...

(1970) *''N. r. simulatrix'' Parkes (1970) *''N. r. cineracea'' Sclater, PL (1881) *''N. r. simplex''

Todd Todd or Todds may refer to: Places Australia * Todd River, an ephemeral river United States * Todd Valley, California, also known as Todd, an unincorporated community * Todd, Missouri, a ghost town * Todd, North Carolina, an unincorporated c ...

(1937) *''N. r. rubecula''

Spix Johann Baptist Ritter von Spix (9 February 1781 – 13 March 1826) was a German natural history, biologist. From his expedition to Brazil, he brought to Germany a large variety of specimens of plants, insects, mammals, birds, amphibians and fish. ...

(1824)

Description

The rusty-breasted nunlet is long and weighs . The subspecies vary in structure and color from each other. In general, the more northerly subspecies have a longer and narrower bill and a shorter tail than the more southerly ones. The nominate subspecies has what amounts to two or three color morphs. Some members of it have plain dark gray-brown upperparts and wings. Their lores are rufous and they have a whitish band from the lores that joins a white ring around the eye. Their tail is dark brown. Their throat, breast, and flanks are brown with a reddish tinge and the abdomen is whitish. Other members of the nominate are paler and grayer, especially on the crown, but in the southeast are a darker brown with a warmer brown tail. Some have a bright orange-rufous (instead of brown) throat, breast, and flanks. ''N. r. tapanahoniensis'' has a very gray crown and a cinnamon tinge to the vent. ''N. r. duidae'' has a rufous chin. ''N. r. interfluvialis'' has a grayer tail and ''N. r. simulatrix'' a darker tail than the others. ''N. r. simplex'' is drab and dark while ''N. r. cineracea'' has warmer brown underparts.

Distribution and habitat

The rusty-breasted nunlet is found in two disjunct areas. The subspecies are distributed thus: *''N. r. tapanahoniensis'', the southern

Guianas The Guianas, also spelled Guyanas or Guayanas, are a geographical region in north-eastern South America. Strictly, the term refers to the three Guianas: Guyana, Suriname, and French Guiana, formerly British Guiana, British, Surinam (Dutch colo ...

and northern Brazil to the left bank of the lower Amazon River; "hypothetical" in French Guiana *''N. r. duidae'', eastern Venezuela north of the

Orinoco River The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

*''N. r. interfluvialis'', southern Venezuela and northern Brazil between the Orninoco and

Negro In the English language, the term ''negro'' (or sometimes ''negress'' for a female) is a term historically used to refer to people of Black people, Black African heritage. The term ''negro'' means the color black in Spanish and Portuguese (from ...

rivers *''N. r. simulatrix'', southeastern Colombia and northwestern Brazil between the Negro and Amazon rivers *''N. r. cineracea'', northeastern Ecuador, northeastern Peru, and western Brazil south of the Amazon *''N. r. simplex'', northern Brazil south of the lower Amazon *''N. r. rubecula'', eastern and southeastern Brazil, eastern Paraguay, and northeastern Argentina The rusty-breasted nunlet primarily inhabits humid '' terra firme'' and '' várzea'' forest, and is also found in

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 ...

and forest edges. It can be found at any level within the forest but is most often in the midstory. In Venezuela it is usually found in areas of sandy soil; in southeastern Brazil's

Paraná state Paraná, Paranã or Parana may refer to: Geology *Paraná Basin, a sedimentary basin in South America Places In Argentina *Paraná, Entre Ríos, a city * Paraná Department, a part of Entre Ríos Province In Brazil *Paraná (state), a state ...

it occurs in

gallery forest A gallery forest is one formed as a corridor along rivers or wetlands, projecting into landscapes that are otherwise only sparsely treed such as savannas, grasslands, or deserts. The gallery forest maintains a more temperate microclimate above th ...

, and in upper

Amazonia The Amazon rainforest, also called the Amazon jungle or Amazonia, is a moist broadleaf tropical rainforest in the Amazon biome that covers most of the Amazon basin of South America. This basin encompasses , of which are covered by the rainf ...

it shuns ''

igapó (, from Tupi language, Old Tupi: "root forest") is a word used in Brazil for Blackwater river, blackwater-flooded forests in the Amazon biome. These forests and similar swamp forests are seasonally inundated with freshwater. They typically occur ...

'' forest.

Behavior

Feeding

The rusty-breasted nunlet's diet is reported to include large

arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...

s, both adult and larval. The nunlet occasionally briefly joins

mixed-species foraging flock A mixed-species feeding flock, also termed a mixed-species foraging flock, mixed hunting party or informally bird wave, is a flock (birds), flock of usually insectivorous birds of different species that join each other and move together while fora ...

Breeding

The rusty-breasted nunlet was thought to nest in a burrow, but a 2020 publication revealed that it nests in a shallow scrape on sloping ground that it roofs with twigs and leaves. Over a seven year period the authors studied 17 nests in Argentina's

Misiones Province Misiones (, ''Missions'') is one of the Provinces of Argentina, 23 provinces of Argentina, located in the northeastern corner of the country in the Mesopotamia, Argentina, Mesopotamia region. It is surrounded by Paraguay to the northwest, Brazil ...

; they were in various stages of construction and use when discovered. Most clutches were of four eggs though one had three. Both sexes incubated the eggs and brooded and fed the nestlings.

Vocalization

The rusty-breasted nunlet's song is "a mewing series of 'weeip, weeip, weeip' notes (up to 20) that rise in both pitch and volume". It does not sing often.

Status

The

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

has assessed the rusty-breasted nunlet as being of Least Concern. It has an extremely large range but its population is unknown and believed to be decreasing. Its apparent density varies from rare to rather common in various parts of the range, though it might be undercounted due to its unobtrusive behavior. It occurs in several protected areas.

References

External links

Rusty-breasted nunlet photo gallery
VIREO {{Taxonbar, from=Q1264332 rusty-breasted nunlet Birds of the Amazon rainforest Birds of the Guiana Shield Birds of Brazil Birds of the Cerrado Birds of Paraguay rusty-breasted nunlet Taxonomy articles created by Polbot