House Wren

Taxobox
name = House Wren

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image_width = 200px
image_caption = Northern House Wren
status = LC
status_system = iucn3.1
regnum = Animalia
phylum = Chordata
classis = Aves
subclassis = Neornithes
infraclassis = Neognathae
superordo = Neoaves
ordo = Passeriformes
subordo = Passeri
infraordo = Passerida
familia = Troglodytidae
genus = "Troglodytes"
species = "T. aedon"
binomial = "Troglodytes aedon"
binomial_authority = (Vieillot, 1809)

The House Wren, "Troglodytes aedon", is a very small songbird of the wren family, Troglodytidae. It occurs from Canada to southernmost South America, and in most of suburban America it is the single most common wren. Its taxonomy is highly complex and some subspecies groups are often considered separate species.

__TOC__Adults are 11.5 cm long and weigh 12 g. The subspecies vary greatly, with upperparts ranging from dull greyish-brown to rich rufescent-brown, and the underparts ranging from brown, over buff and pale grey, to pure white. All subspecies have blackish barring to the wings and tail, and some also to the flanks. All subspecies show a faint eye-ring and eye-brow and have a long, thin bill with a blackish upper mandible, and a black-tipped yellowish or pale grey lower mandible. The legs are pinkish or grey. The short tail is typically held cocked.

This bird's rich bubbly song is commonly heard during the nesting season but rarely afterwards. There is marked geographical variation in its song, though somewhat more gradual than in the birds' outward appearance which can strikingly differ e.g. on neighboring islands in the CaribbeanVanderGaast & Jaramillo (2005)] . Birds from far north and south of the species' range nonetheless have songs that differ markedly.

ystematics and taxonomy

The House Wren is usually divided into three distinct subspecies groups and one or several distinct island-endemic subspecies. Some or all of these are often considered distinct species.
* Northern House Wren, "Troglodytes (aedon) ardon" group – Canada to southern USA
* Brown-throated Wren, "Troglodytes (aedon) brunneicollis" group – southern USA and central ranges of Mexico
* Cozumel Wren, "Troglodytes (aedon) beani" – Cozumel Island off the Yucatan Peninsula, Mexico
* Southern House Wren, "Troglodytes (aedon) musculus" group – southern Mexico, Central and South AmericaIt has also been suggested that the taxa from the Lesser Antilles represent one or more separate species, but there is less agreement as to their subdivision, because as far as they have been studied to date, there is little clear biogeographical structure among these populations.

Three additional taxa from more oceanic islands were in former times included in the House Wren, but are now considered separate species:
* Cobb's Wren, "Troglodytes cobbi" – Falkland Islands (South Atlantic)
* Socorro Wren, "Troglodytes sissonii" – Socorro, Revillagigedo Islands
* Clarion Wren, "Troglodytes tanneri" – Clarion, Revillagigedo Islands (East Pacific)The Socorro Wren is a highly distinct form, appearing somewhat like a mixture between a House Wren and a Bewick's Wren.

Ecology

In North America, the House Wren is thought to achieve the highest density in floodplain forests in the western great plains where it uses woodpecker holes as nesting sites. In South and Central American it can be found in virtually any habitat and is, as indicated by its common name, often associated with humans. North American birds migrate to the southern United States and Mexico for winter. Most return to the breeding grounds in late April to May, and leave for winter quarters again around September to early October [OOS (2004)] . These birds forage actively in vegetation. They mainly eat insects such as butterfly larvae, also spiders and snails.

Reproduction

The nesting habits do not seem to differ significantly between the Northern and Southern House Wrens at least. They usually construct a large cup nest in various sorts of cavities, taking about a week to build. Nest cavities are usually a few meters above ground at most, but occasionally on cliffs as high up as 15 meters and more at least in southern populationsVerify source|date=February 2008 ; they may be natural or man-made, often using bird houses where they are available, and sometimes choosing unusual sites such as old shoesFact|date=February 2008.

House Wrens are feisty and pugnacious animals considering their tiny size. They are known to occasionally destroy the eggs of other birds nesting in their territory by breaking the eggshell. They are also known to fill up other birds' nests within its territory with sticks to make them unusable.

The House Wrens' clutch is three to six red-blotched cream-white eggs, weighing about 1.4 grams each and measuring c.17 and 13.4 mm at the widest points. Only the female incubates these, for around 14-16Fact|date=February 2008 days, and she will every now and then leave the nest for various reasons. When on the nest, the male provisions her with food. The young, which like all passerines hatch almost naked and helpless, take another 15-19 days or so to fledgeFact|date=February 2008 . They are being fed by both parents, and need plenty of food given their tiny size (see also Bergmann's Rule). As the young near fledging, the parents spend much of their time procuring food for them. Brood loss due to predation was found to be light in the Southern Andean Yungas, with predation of nestling young being almost insignificant.Auer "et al." (2007)]

Migrant populations are nesting within 6 weeks of returning from winter quarters, leaving theoretically time for a second brood [Henninger (1906), OOS (2004)] . In the subtropical montane forest of northwestern Argentina and similar habitat, the Southern House Wren breeds in the rainy summer months from late October to late December.

Conservation status

The House Wren may have been displaced somewhat in some northern parts of its range by the introduction of the House Sparrow, but is still common and widespread throughout most of the Americas. It is not considered threatened by the IUCN, though this would certainly not hold true for several of the island population if they turn out to be good species.

Some taxa, especially from the Lesser Antilles, are rare and highly endangered or possibly already extinct. Several factors seem to have contributed to a varying degree to the decline of these birds, namely habitat destruction, predation by introduced mongooses, and hurricanes:
* Martinique Wren, "Troglodytes aedon martinicensis") – Martinique, apparently extinct (c.1890)
* Guadeloupe Wren, "Troglodytes aedon guadeloupensis" – Guadeloupe, possibly extinct (late 20th century?)
* Saint Lucia Wren, "Troglodytes aedon mesoleucus" – Saint Lucia, believed extinct by 1970s, subsequently rediscovered but still precariously rareThe Saint Vincent Wren ("Troglodytes aedon musicus") of Saint Vincent was close to extinction in the mid-late 20th century; it has since recovered and today is not uncommon

As remarked above, these are variously placed in "T. musculus" if that is considered distinct, or as one or several distinct species.

House Wrens and humans

Its diminutive size and seemingly overconfident and bold behavior make the House Wren a well-liked bird to many Americans. House Wrens can be encouraged to nest in gardens in their range by offering nest boxes with hole small enough to prevent competitive cavity nesters.

King Friday XIII, a protagonist of the PBS children's educational program "Mister Rogers' Neighborhood", had a wooden wren upon a stick that he often played with as a cherished toy. This bird was referred to as House Wren when the King composed and sang a song about his toy, mentioning the scientific name "Troglodytes aedon".

References

References

* (2007): Breeding biology of passerines in a subtropical montane forest in Northwestern Argentina. [English with Spanish abstract] "Condor" 109(2): 321-333. DOI:10.1650/0010-5422(2007)109 [321:BBOPIA] 2.0.CO;2 [http://www.umt.edu/mcwru/files.pdf/Tom's%20PDF/Auer%20et%20al%20%202007%20Condor%20Argentina%20breeding%20biology.pdf PDF fulltext]
*|year=2004|id=52036|title=Troglodytes aedon|downloaded=12 May 2006 Database entry includes justification for why this species is of least concern
* (1991): "A guide to the birds of Trinidad and Tobago" (2nd edition). Comstock Publishing, Ithaca, N.Y.. ISBN 0-8014-9792-2
* (1906): A preliminary list of the birds of Seneca County, Ohio. "Wilson Bull." 18(2): 47-60. [http://elibrary.unm.edu/sora/Wilson/DJVU/v018n02/P0047-P0060.djvu DjVu fulltext] [http://elibrary.unm.edu/sora/Wilson/v018n02/p0047-p0060.pdf PDF fulltext]
* (2003): "Birds of Venezuela". Christopher Helm, London. ISBN 0-7136-6418-5
* (2004): Annotated Ohio state checklist. Version of April 2004. [http://www.ohiobirds.org/publications/OBRClist.pdf PDF fulltext]
* (2005): Field Guides Incorporated Trip List - Lesser Antilles April 9, 2005 to April 23, 2005. [http://www.fieldguides.com/2005weblists/les05LIST.pdf PDF fulltext]

External links

* [http://ibc.hbw.com/ibc/phtml/especie.phtml?idEspecie=5761 House Wren videos] on the Internet Bird Collection
* [http://www.sdakotabirds.com/species/house_wren_info.htm House Wren Information and Photos] - South Dakota Birds and Birding
* [http://www.mbr-pwrc.usgs.gov/id/framlst/i7210id.html House Wren - "Troglodytes aedon"] - USGS Patuxent Bird Identification InfoCenter
* [http://www.birds.cornell.edu/AllAboutBirds/BirdGuide/House_Wren.html House Wren Species Account] - Cornell Lab of Ornithology
* [http://www.youtube.com/watch?v=zjK2mL5GaMk House Wren] - Video at YouTube
* [http://www.faunascope.com/faunascope/house_wren/index.html Videos from inside a house wren nest] - Video clips showing development from eggs to fledglings (Faunascope)
* [http://www.bird-stamps.org/cspecies/13505600.htm Stamps]