The grey-cheeked nunlet (''Nonnula frontalis'') 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

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 ...

and

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

Taxonomy and systematics

The grey-cheeked nunlet was first described by P.L. Sclater in 1854 in

. Three subspecies are generally recognized, the nominate ''N. f. frontalis'', ''N. f. stulta'', and ''N. f. pallescens''. The nominate has been suggested to constitute more than one taxon based on differences in coloration observed in specimens. ''N. f. pallescens'' has occasionally been suggested to be a subspecies of the rufous-capped nunlet (''N. ruficapilla'') of southern Amazonia. The grey-cheeked nunlet forms a

superspecies In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

with the rufous-capped nunlet and the chestnut-headed nunlet (''N. amaurocephala''), which is restricted to a small area in northwest

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 ...

. It has been suggested to be

conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organism ...

with the rufous-capped nunlet and also with the brown nunlet (''N. brunnea'').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, 2021Remsen, 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. and N. Collar (2020). Gray-cheeked Nunlet (''Nonnula frontalis''), 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.gycnun1.01 retrieved November 10, 2021

Description

The grey-cheeked nunlet is long and weighs . The nominate subspecies has a very dark chestnut crown and plain brown upperparts, lighter on the rump. Most of the face is gray with a ring of bare red skin around the dark brown eye. The tail is dark brown and almost black near the tip. The chin, throat, breast, and flanks are rufous and the belly is buffy. The bill is mostly blue-gray and the feet dull brown or greenish gray. ''N. f. stulta'' has a very dark crown and its tail is blacker and rump drabber than those of the nominate. ''N. f. pallescens'' has much paler upperparts than the nominate and its throat and breast are buff.

Distribution and habitat

The grey-cheeked nunlet has a somewhat restricted range that extends from central Panama to north-central Colombia. ''N. f. stulta'' is the northernmost subspecies; it is found from central Panama into extreme northwestern Colombia. ''N. f. pallescens'' is found in the Caribbean lowlands of northern Colombia. The nominate subspecies is found in the interior of northern Colombia. The species inhabits a variety of landscapes including moist to humid

primary Primary or primaries may refer to: Arts, entertainment, and media Music Groups and labels * Primary (band), from Australia * Primary (musician), hip hop musician and record producer from South Korea * Primary Music, Israeli record label Work ...

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 ...

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 thickets; it especially favors woodlands along rivers. it usually inhabits the lower levels of the forest but can be found up to the subcanopy. In elevation it ranges from sea level to .

Behavior

Feeding

The grey-cheeked nunlet's feeding behavior has not been documented, though it has been observed taking a variety of

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 ...

prey. It sometimes 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 grey-cheeked nunlet breeds from February to June in Colombia but little else is known about its breeding

phenology Phenology is the study of periodic events in biological life cycles and how these are influenced by seasonal and interannual variations in climate, as well as habitat factors (such as elevation). Examples include the date of emergence of leav ...

. The nesting behavior of the entire genus ''

Nonnula ''Nonnula'' is a genus of puffbird in the Bucconidae family. They are commonly known as nunlets. Extant Species It contains the following species: References

Nonnula, Bird genera Taxa named by Philip Sclater Taxon ...

'' is poorly understood, but the rusty-breasted nunlet (''N. rubecula'') nests in a shallow scrape that it covers with twigs and leaves. That species' clutch size is usually four eggs.

Vocalization

The grey-cheeked nunlet's song is a "plaintive, measured series of up to 20 notes, 'weeip weeip, weeip...'."

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 grey-cheeked nunlet as being of Least Concern, though its population is estimated to be fewer than 50,000 mature individuals and decreasing. The species is considered uncommon to rare in Panama and generally fairly common in Colombia.

References

{{Taxonbar, from=Q1264077 grey-cheeked nunlet Birds of Panama Birds of Colombia grey-cheeked nunlet grey-cheeked nunlet Taxonomy articles created by Polbot