Black-tailed Gnatcatcher

Taxobox
name = Black-tailed Gnatcatcher
status = LC | status_system = IUCN3.1
regnum = Animalia
phylum = Chordata
classis = Aves
ordo = Passeriformes
familia = Polioptilidae
genus = "Polioptila"
species = "P. melanura"
binomial = "Polioptila melanura"
binomial_authority = (Lawrence, 1857)

The Black-tailed Gnatcatcher ("Polioptila melanura") is a small, insectivorous bird which ranges throughout the Sonoran and Chihuahuan Deserts of the southwestern United States and northern Mexico. It is nonmigratory and found in arid desert areas year-round.

Taxonomy

The Black-tailed Gnatcatcher was described by American ornithologist George Newbold Lawrence in 1857. Meaning 'black-tailed', its specific name is derived from the Ancient Greek "melano-" 'black' and "oura" 'tail'.cite book | author = Liddell, Henry George and Robert Scott | year = 1980 | title = A Greek-English Lexicon (Abridged Edition) | publisher = Oxford University Press | location = United Kingdom | isbn =0-19-910207-4]

Description

The Black-tailed Gnatcatcher reaches about 4.5 to 5 inches in length, much of it taken up by a long black tail lined with white outer feathers. The body is blue-gray, with white underparts, and while it is similar to the Blue-gray Gnatcatcher, the two birds are differentiated by the amount of black in the tail feathers. The male has a black cap during the summer that extends to the eyes. Females and winter males, lacking the black cap, are difficult to distinguish from the Blue-gray Gnatcatcher. The best way to tell the two apart is the tail; that of the blue-gray is mostly white when viewed from below, and the black-tailed is predominantly black underneath. Like other gnatcatchers, it may give harsh, scolding calls while foraging for small insects and spiders in desert shrubs.cite book | last = Steven J. Phillips, Patricia Wentworth Comus (eds.) | title = A Natural History of the Sonoran Desert | publisher = University of California Press | date = 2000 | pages = 464-466 | isbn = 0-520-21980-5 ]

Behaviour

Black-tailed Gnatcatchers live in pairs all year, defending their territory and foraging in trees and low shrubs for a wide variety of small insects and some spiders. Unlike the Blue-gray Gnatcatcher, the black-tailed variety rarely catches insects in midair.

Breeding

The nest is an open-cup, built by both sexes, and is typically found in low shrubs less than five feet off the ground. It is constructed of a variety of materials including weeds, grass, strips of bark, spider webs and plant fibers. It is lined with finer, softer matter. Three to five bluish-white eggs with red-brown dots are incubated by both parents and take 14 days to hatch. The young are fed by both parents, and leave the nest 10 to 15 days after hatching. Even though cowbirds aften lay eggs in this species' nests, and the pair end up raising cowbird young, the Black-tailed Gnatcatcher population seems to be holding up well.

References

* Database entry includes justification for why this species is of least concern

*ITIS|ID=179857|taxon=Polioptila melanura|year=2006|date=24 January

External links

* [http://www.mbr-pwrc.usgs.gov/id/framlst/i7520id.html Black-tailed Gnatcatcher]
* [http://www.bird-friends.com/BirdPage.php?name=Black-Tailed%20Gnatcatcher Black-tailed Gnatcatcher] at birdfriends.com
* [http://vireo.acnatsci.org/search.html?Form=Search&SEARCHBY=Common&KEYWORDS=black-tailed+gnatcatcher&showwhat=images&AGE=All&SEX=All&ACT=All&Search=Search&VIEW=All&ORIENTATION=All&RESULTS=24 Black-tailed Gnatcatcher photo gallery] VIREO [http://vireo.acnatsci.org/species_image.php?species=Polioptila+melanura Photo-High Res--(Close-up)]
* [http://www.sdakotabirds.com/species_photos/black_tailed_gnatcatcher.htm Black-tailed Gnatcatcher Photos] South Dakota Birds and Birding