Streaked xenops

{{Short description|Species of bird}}

{{Use American English|date=August 2023}}

{{Speciesbox

| name = Streaked xenops

| image = Xenops rutilans -Piraju, Sao Paulo, Brazil-8.jpg

| image_caption = In Piraju, São Paulo, Brazil

| status = LC

| status_system = IUCN3.1

| status_ref = {{cite iucn |author=BirdLife International. |year=2020 |title=Streaked Xenops Xenops rutilus |volume=2020 |page=e.T22702998A168545979 |doi=10.2305/IUCN.UK.2020-3.RLTS.T22702998A168545979.en |access-date=16 August 2023}}

| genus = Xenops

| species = rutilans

| authority = Temminck, 1821

| range_map = Xenops rutilans map.svg

| synonyms = Xenops rutilusHBW and BirdLife International (2022) Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 7. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v7_Dec22.zip retrieved December 13, 2022

}}

The streaked xenops (Xenops rutilans) is a passerine bird in the Furnariinae subfamily of the ovenbird family Furnariidae. It is found in the New World from Costa Rica and Trinidad south to Bolivia and Argentina.{{cite web |url=https://www.worldbirdnames.org/new/bow/ovenbirds/ |title=Ovenbirds, woodcreepers |website=IOC World Bird List |version =v 13.2 | editor1-last=Gill | editor1-first=Frank | editor1-link=Frank Gill (ornithologist) | editor2-last=Donsker | editor2-first=David | editor3-last=Rasmussen | editor3-first=Pamela | editor3-link=Pamela Rasmussen |date=July 2023 |access-date=July 31, 2023 }}

Taxonomy and systematics

Early on the streaked xenops was assigned the binomial Xenops rutilus. In the mid 1900s taxonomists began using X. rutilans. By the principle of priority the earlier rutilus is correct but because of the long usage of rutilans most systems have stayed with that specific epithet.Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, G. Del-Rio, A. Jaramillo, D. F. Lane, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 31 May 2023. A classification of the bird species of South America. American Ornithological Society. https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm retrieved May 31, 2023Clements, J. F., T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, S. M. Billerman, B. L. Sullivan, and C. L. Wood. 2022. The eBird/Clements checklist of birds of the world: v2022. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ retrieved November 10, 2022Chesser, R. T., S. M. Billerman, K. J. Burns, C. Cicero, J. L. Dunn, B. E. Hernández-Baños, R. A. Jiménez, A. W. Kratter, N. A. Mason, P. C. Rasmussen, J. V. Remsen, Jr., and K. Winker. 2023. Check-list of North American Birds (online). American Ornithological Society. https://checklist.americanornithology.org/taxa/ A major exception is BirdLife International's Handbook of the Birds of the World (HBW), which uses X. rutilus.

The major worldwide taxonomic systems recognize these 11 subspecies:

Description

The streaked xenops is about {{convert|12|to|13|sigfig=2|cm|in|abbr=on}} long and weighs {{convert|10|to|15|g|oz|sigfig=2|abbr=on}}. Its bill is wedge-shaped, short, and thick. The sexes are alike. The nominate subspecies X. r. rutilans has somewhat variable plumage. Adults generally have a conspicuous buff supercilium and a pure white malar stripe on an otherwise brownish face with some darker and lighter highlights. Their crown is dark brown with rufous streaks. Their back is rufescent brown with faint paler rufous streaks, their rump and uppertail coverts plain chestnut-rufous, and their tail chestnut-rufous with a blackish inner web on one pair of feathers. Their wing coverts are rufescent-brown with darker inner webs and their flight feathers are dark fuscous and all but the inner pair have a rufous tinge on their outer webs. Their throat and uppermost breast are whitish with darker mottling. The rest of their underparts have wide buffy whitish streaks with dark brownish edges on a medium brownish background; the streaks narrow and fade on the lower belly. Their iris is brown to dark brown, their maxilla dark brown to blackish, their mandible whitish to pinkish gray with a blackish tip, and their legs and feet gray to black. Juveniles differ from adults with less distinct streaking, less black on the tail, and a cloudy grayish throat.Remsen, Jr., J. V. (2020). Streaked Xenops (Xenops rutilans), 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.strxen1.01 retrieved August 16, 2023

The other 10 subspecies of the streaked xenops differ in varying degrees from the nominate, though much of the differences fall within the variability of the nominate's plumage. The differences tend to be in the intensity of the rufous of the upperparts, the size and exact color of the underparts' streaks, and the exact base color of the underparts.

Distribution and habitat

The 11 subspecies of the streaked xenops are found thus:

In the Andes and Central American mountains the streaked xenops inhabits montane evergreen and deciduous forests, mostly at elevations between {{convert|700|and|2400|m|ft|abbr=on}}. In Costa Rica it occurs from {{convert|1200|to|2500|m|ft|abbr=on}} and in Colombia from {{convert|1400|to|2800|m|ft|abbr=on}}. In the lowlands it inhabits a wide variety of forest and woodland landscapes that range from semi-arid to humid. They include tropical deciduous and tropical lowland evergreen primary forest and also secondary forest. It is found in the forest interior and at its edges. In Ecuador it reaches {{convert|2000|m|ft|abbr=on}} in the west and spans from {{convert|800|to|2000|m|ft|abbr=on}} in the east. Much of its Brazilian range is at low elevation but it reaches as high as {{convert|2400|m|ft|abbr=on}} in that country.{{cite book |last1=Garrigues |first1=Richard |last2=Dean |first2=Robert |date=2007 |title=The Birds of Costa Rica |location=Ithaca |publisher=Zona Tropical/Comstock/Cornell University Press |page=168 |isbn=978-0-8014-7373-9 }}{{cite book | last1 =McMullan | first1 =Miles | last2 =Donegan | first2 =Thomas M. | last3 =Quevedo | first3 =Alonso | title = Field Guide to the Birds of Colombia | publisher = Fundación ProAves| date =2010 | location =Bogotá | pages =123 |isbn =978-0-9827615-0-2 }}{{cite book | last =Ridgely | first =Robert S. | last2 =Greenfield | first2 =Paul J. | title =The Birds of Ecuador: Field Guide | publisher =Cornell University Press | volume = II| date =2001 | location =Ithaca | pages =374 | isbn =978-0-8014-8721-7 }}de L. Fávaro, Fernando; dos Anjos, Luiz; Lopes, Edson V.; Mendonça, Luciana B. & Volpato, Graziele H. (2006): Efeito do gradiente altitudinal/latitudinal sobre espécies de aves florestais da família Furnariidae na Bacia do Rio Tibagi, Paraná, Brasil [Effect of altitudinal/latitudinal gradient about forest ovenbirds species (Aves: Furnariidae) in the Tibagi river basin, Paraná, Brazil]. Revista Brasileira de Zoologia 23(1): 261–266 [Portuguese with English abstract]. {{doi|10.1590/S0101-81752006000100020}} [https://www.scielo.br/pdf/rbzool/v23n1/a20v23n1.pdf PDF fulltext]{{cite book | last =van Perlo | first = Ber| title =A Field Guide to the Birds of Brazil | publisher =Oxford University Press | date =2009 | location =New York | pages =228 | isbn =978-0-19-530155-7 }}

Behavior

=Movement=

The streaked xenops is a year-round resident throughout its range.

=Feeding=

The diet of the streaked xenops is arthropods. The larvae of wood-boring beetles have been documented as an item in addition to adult arthropods. Single birds and pairs often join mixed-species foraging flocks. They feed in the forest understory at its edges and from the mid levels to its subcanopy in the interior. It climbs and hitches along slender branches and sometimes uses its tail as a brace, catching prey by gleaning, chiseling, and flaking bark and rotten wood. It has also been observed catching flying termites in mid-air.Machado, C.G. (1999): A composição dos bandos mistos de aves na Mata Atlântica da Serra de Paranapiacaba, no sudeste brasileiro [Mixed flocks of birds in Atlantic Rain Forest in Serra de Paranapiacaba, southeastern Brazil]. Revista Brasileira de Biologia 59(1): 75-85 [Portuguese with English abstract]. {{doi|10.1590/S0034-71081999000100010}} [https://www.scielo.br/pdf/rbbio/v59n1/v59n1a10.pdf PDF fulltext]Olson, Storrs L. & Alvarenga, Herculano M. F. (2006): An extraordinary feeding assemblage of birds at a termite swarm in the Serra da Mantiqueira, São Paulo, Brazil. Revista Brasileira de Ornitologia 14(3): 297-299 [English with Portuguese abstract]. [https://web.archive.org/web/20081217160357/http://www.ararajuba.org.br/sbo/ararajuba/artigos/Volume143/ara143not6.pdf PDF fulltext]

=Breeding=

The streaked xenops' breeding season has not been determined in most of its range. In Costa Rica it spans from January to May and on Trinidad from February to May. It nests in a cavity, whether natural, excavated by a small woodpecker, or excavated itself, and adds a small amount of soft plant fiber to the bottom. Nests have been noted between {{convert|1.5|to|9|m|ft|0|abbr=on}} above the ground. The clutch size is two or three eggs. The incubation period, time to fledging, and details of parental care are not known.

{{birdsong|url=https://xeno-canto.org/species/Xenops-rutilans |species=streaked xenops}}

=Vocalization=

The song of the streaked xenops is "an ascending and then descending, high-pitched series of 5–10 dry, squeaky 'swee' or 'zeet' notes, accelerating at [the] end". Its calls are "a high, piercing 'peet' or 'cheet' ".

Status

The IUCN has assessed the streaked xenops as being of Least Concern. It has an extremely large range and its estimated population of at least five million mature individuals is believed to be stable. No immediate threats have been identified. It is considered uncommon to fairly common across most of its range and occurs in many protected areas. It "[a]ppears fairly tolerant of habitat disturbance; survives in small and degraded forest fragments, although in some cases at lower densities".

References