Eurasian Wren

## Description

The Eurasian wren (Troglodytes troglodytes ) or northern wren is a very small insectivorous bird, and the only member of the wren family Troglodytidae found in Eurasia and Africa (Maghreb). In Anglophone Europe, it is commonly known simply as the wren. It has a very short tail which is often held erect, a short neck and a relative long thin bill. It is russet brown above, paler buff-brown below and has a cream buff supercilium. The sexes are alike.

It was once lumped with Troglodytes hiemalis of eastern North America and Troglodytes pacificus of western North America as the winter wren. The Eurasian wren occurs in Europe and across the Palearctic – including a belt of Asia from northern Iran and Afghanistan across to Japan. It is migratory in only the northern parts of its range. It is also highly polygynous, an unusual mating system for passerines.

The scientific name is taken from the Greek word "troglodytes" (from τρώγλη troglē "hole", and δῠ́ειν dyein, "creep"), meaning "hole-dweller", and refers to its habit of disappearing into cavities or crevices whilst hunting arthropods or to roost. The taxonomy of the genus Troglodytes is currently unresolved, as recent molecular studies have suggested that Cistothorus spp. and Thryorchilus spp. are within the clade currently defined by Troglodytes.

## Appearance

The Eurasian wren is a very small insectivorous bird found in Eurasia and North Africa. It has a very short tail which is often held erect, a short neck, and a relatively long thin bill. It is russet brown above, paler buff-brown below, and has a cream buff supercilium. The male and the female are alike.

## Distribution

Eurasian wrens occur in Europe and across the Palearctic including a belt of Asia from northern Iran and Afghanistan across to Japan. They are migratory in only the northern parts of their range. Eurasian wrens live in a great variety of habitats including cultivated or uncultivated areas with bushes and low ground covers; gardens, hedgerows, thickets, plantations, woodland, and reed beds. They inhabit more open locations with clumps of brambles or gorse, rough pasture, moorland, boulder-strewn slopes, rocky coasts, and sea cliffs.

## Behavior

Eurasian wrens are active birds, constantly on the move foraging for insects, in the open or among thick vegetation. They move with quick jerks, probing into crevices, examining old masonry, hopping onto fallen logs, and delving down among them. They sometimes move higher in the canopy, but for the most part stay near the ground, often being flushed from under overhangs on banks. Sometimes they hop up the lower part of tree trunks. They may also flit away their tiny round wings whirring as they fly. Eurasian wrens are birds of the uplands even in winter, vanishing into the heather when snow lies thick above. At night, usually in winter, they often roost, true to their scientific name, in dark retreats, snug holes, and even old nests. In hard weather, they may do so in parties, consisting of either the family or of many individuals gathered together for warmth. The most common call of Eurasian wrens is a sharp, repeated 'tic-tic-tic'. When the birds are annoyed or excited, their call runs into an emphatic 'churr'. The song is a gushing burst of sweet music, clear, shrill, and emphatic. The males have remarkably long and complex vocalizations, with a series of tinkling trills one after the other for seconds on end. They have an enormous voice for their size and despite their secretive behavior the males sometimes sing from an exposed low perch. Their song begins with a few preliminary notes, then runs into a trill, slightly ascending, and ends in full clear notes or another trill. The song may be heard at any season, though most noticeable during spring.

## Diet

Eurasian wrens are carnivores (insectivores) and insects form the bulk of their diet. Other dietary items include spiders, and some seeds are also taken. The young are largely fed on moth larvae, with caterpillars of the cabbage moth and crane fly larvae.

## Reproduction

Eurasian wrens are highly polygynous; a male can have, at any one time, more than one female with an active nest on his territory. An active nest is one in which there are eggs or nestlings. Some males have been recorded with four females breeding on his territory. The male builds several nests in his territory; these are called "cock nests" but are never lined until the female chooses one to use. The number of nests on a territory influences the female's choice of mate; she prefers to choose a male that had constructed numerous nests. Courtship includes display and posturing by the male. He sings with wings and tail half-open, or with them drooping, sometimes with one wing extended, or the wings may be raised and lowered several times in quick succession. The neatly-domed nest has a side entrance and is built of grass, moss, lichen, and dead leaves, whatever is available locally. It is often tucked into a hole in a wall or tree trunk or a crack in a rock, but it is often built in brambles, a bush or a hedge, among ivy on a bank, in thatch, or in abandoned bird's nests. On making her selection, the female wren lines the nest generously with feathers. A clutch of 5-6 eggs is laid from April onwards. These are white with variable amounts of reddish-brown speckles, mostly on the broad end. The female alone incubates the eggs for 14 to 15 days. The chicks hatch blind and helpless and fledge after about 16 days. There are usually two broods.

## Population

### Threats

There are no major threats to the Eurasian wren at present.

### Number

According to the IUCN Red List, the total population size of the Eurasian wren is 10,000,000-500,000,000 mature individuals. In Europe, the breeding population consists of 32,700,000-56,500,000 pairs, which equates to 65,300,000-113,000,000 mature individuals. National population estimates include around 10,000-100,000 breeding pairs in China; around 100-100,000 breeding pairs in Taiwan; possibly around 10,000-100,000 breeding pairs in Korea; around 100-100,000 breeding pairs in Japan and possibly around 10,000-100,000 breeding pairs and around 1,000-10,000 individuals on migration in Russia. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and but its numbers today are decreasing.

## Fun Facts

The scientific name of the Eurasian wren is taken from the Greek word "troglodytes" meaning "cave-dweller", and refers to its habit of disappearing into cavities or crevices whilst hunting arthropods or to roost.

In European folklore, the wren is the king of the birds, according to a fable attributed to Aesop by Plutarch, when the eagle and the wren strove to fly the highest, the wren rested on the eagle's back, and when the eagle tired, the wren flew out above him. Thus, Plutarch implied, the wren proved that cleverness is better than strength.

In Japan, the wren is labeled the king of the winds, and the myth of "The Wren Among the Hawks" sees the wren successfully hunt a boar that the hawks could not, by flying into its ear and driving it mad.

The Wren is one of the animals of the Celtic zodiac.

Wrens have been featured on stamps of many countries including Albania, Albany, Belarus, Belgium, Bulgaria, Faroe Islands, France, Germany, Britain, Guernsey, Hungary, Iceland, Ireland, Isle of Man, Jersey, Netherlands, San Mario, USA and The Vatican.