Dwarf vireo

{{Speciesbox | name = Dwarf vireo | image = Dwarf Vireo (Vireo nelsoni).jpg | status = LC | status_system = IUCN3.1 | status_ref = <ref name=IUCN>{{cite iucn |author=BirdLife International |date=2021 |title=Dwarf Vireo ''Vireo nelsoni'' |volume=2021 |article-number=e.T22705179A137794525 |doi=10.2305/IUCN.UK.2021-3.RLTS.T22705179A137794525.en |access-date=6 December 2025}}</ref> | genus = Vireo | species = nelsoni | authority = Bond, 1934 | synonyms = | range_map = Vireo nelsoni map.svg }}

The '''dwarf vireo''' ('''''Vireo nelsoni''''') is a species of bird in the family Vireonidae, the vireos, greenlets, and shrike-babblers. It is endemic to Mexico.<ref name=IOC15.1>{{cite web |url=https://www.worldbirdnames.org/new/bow/shrikes/ |title=Vireos, shrike-babblers |website=IOC World Bird List |version =v 15.1 | 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=March 2025 |access-date=3 March 2025 }}</ref>

==Taxonomy and systematics==

The dwarf vireo was originally described in 1898 as ''Vireo nanus'', but in 1934 James Bond recognized that the binomial ''V. nanus'' had already been used for the flat-billed vireo. Bond coined the species' present binomial and is credited with the first valid naming.<ref name=AOU1998>{{cite book | last = | first = | title =Check-list of North American Birds | publisher =American Ornithologists' Union |edition =7th | date =1998 | location =Washington, D.C. | pages =433 }}</ref><ref>{{cite journal |last=Nelson |first=Edward William |date=1898 |title=Descriptions of New Birds from Mexico |url=https://www.biodiversitylibrary.org/item/24139#page/81/mode/1up |journal=Proc. Biol. Soc. Wash. |volume=12 |pages=59 |access-date=December 6, 2025 }}</ref><ref>{{cite journal |last=Bond |first=James |date=1934 |title=The Systematic Position of Lawrencia and Laletes |url=https://www.jstor.org/stable/4064157?read-now=1&seq=1#page_scan_tab_contents |journal=Proc. Acad. Nat. Sci. Philadelphia |volume=86 |pages=399–402 |access-date=December 6, 2025 }}</ref><ref>{{cite journal |last=Bond |first=James |date=1936 |title=Vireo nelsoni Bond |url=https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=14084&context=auk |journal=The Auk |volume=53 |issue=4 |pages=458 |access-date=December 6, 2025 }}</ref>

The dwarf vireo is monotypic.<ref name=IOC15.1/>

==Description==

The dwarf vireo is {{convert|10|to|11|cm|in|sigfig=2|abbr=on}} long; two individuals weighed {{convert|9.2|and|9.4|g|oz|sigfig=2|abbr=on}}. The sexes have similar plumage. Adult males have a bluish gray crown and adult females an olive crown. Both sexes have grayish white lores and a grayish white eye-ring with a gap above the eye on an otherwise grayish olive to olive face. Their upperparts are grayish olive to olive. Their wing coverts are dusky with grayish white tips that form two wing bars. Their flight feathers are dusky with pale olive gray edges. Their tail is dusky with pale yellowish olive green edges on the feathers. Their throat and underparts are white with a faint grayish wash on the breast. They have a reddish iris, a black or blackish bill, and blue-gray legs and feet.<ref name=DWVI-BOW>Rodríguez-Flores, C. I., C. A. Soberanes-González, M. d. C. Arizmendi, G. M. Kirwan, and T. S. Schulenberg (2020). Dwarf Vireo (''Vireo nelsoni''), version 1.0. In Birds of the World (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.dwavir1.01 retrieved December 6, 2025</ref><ref name=vanPerlo2>{{cite book | last =vanPerlo | first =Ber | title =Birds of Mexico and Central America | publisher =Princeton University Press | series =Princeton Illustrated Checklists | date =2006 | location =New Jersey | pages =Plate 78, map 78.7 | isbn =0691120706 }}</ref>

==Distribution and habitat==

The dwarf vireo is found inland in southwestern Mexico from Jalisco and southern Guerrero south to central Oaxaca. It inhabits dry (semi-arid to arid) scrublands that often have oaks. In elevation it ranges between {{convert|1000|and|2500|m|ft|abbr=on}}.<ref name=DWVI-BOW/><ref name=vanPerlo2/>

==Behavior== ===Movement===

The dwarf vireo is a probably a year-round resident though a few authors have suggested seasonal elevational movements.<ref name=AOU1998/><ref name=DWVI-BOW/>

===Feeding===

The dwarf vireo's diet is not known though it is assumed to eat mostly arthropods and some fruit. It typically forages singly or in pairs and typically near the ground.<ref name=DWVI-BOW/>

===Breeding===

The dwarf vireo's breeding season has not been detailed but is known to include June. Its nest has not been described beyond that it is placed at low to medium levels above the ground in a tree or bush. Nothing else is known about the species' breeding biology.<ref name=DWVI-BOW/>

{{birdsong|url=https://xeno-canto.org/species/Vireo-nelsoni |species=the dwarf vireo}} ===Vocalization===

One description of the dwarf vireo's song is "rich to slightly scratchy, hurried warbling phrases, often prolonged, and short, scratchy, warbled phrases, ''whee chi-a-wee wee-chi'', or ''wee ch'wee wee chir'-awee'', or ''wi chee'r ch wit'', etc.". Its calls include "a short, dry ''dri-dri-it'' or ''chi-chi chi-chi-chi'',...a gnatcatcher ''Polioptila''-like mewing ''meearr-meear'', and a scolding ''cheh-cheh''...or ''jeh-jeh-jehr''".<ref name=DWVI-BOW/>

==Status==

The IUCN originally in 1994 assessed the dwarf vireo as Near Threatened and since 2000 as being of Least Concern. It has a large range; its estimated population of 20,000 to 50,000 mature individuals is believed to be decreasing. No immediate threats have been identified.<ref name=IUCN/> Its abundance has been variously described as "very uncommon" and "uncommon to fairly common but local".<ref name=DWVI-BOW/>

==References== {{Reflist}}

Category:Vireo (genus) Category:Endemic birds of Mexico Category:Mexican montane bird species Category:Natural history of the Mexican Plateau Category:Birds described in 1936 Category:Taxa named by James Bond (ornithologist) Category:Taxonomy articles created by Polbot