Wren Life Cycle: Nest Building To Fledging (and everything in between)

The Wren (Troglodytes troglodytes), or Eurasian Wren or northern Wren as it is also known, is a small, plump, sturdy bird with rounded wings and a short tail. The Wren is slightly larger than the Goldcrest and has long legs and toes.

Wrens are easy to identify with their reddish-brown backs, greyish underparts with bars of darker brown and grey which spreads as far as the wings and tail. They have dark brown bills and pale brown legs.

Wrens have a loud voice and are extremely vocal birds. With their calls being around ten times as loud as that of a Cockerel weight for weight.

In this article we’ll be looking at the life cycle of the Wren from the laying of their eggs to the fledging of their chicks, and much more besides. Come with us on this remarkable voyage of discovery into the secret life of the Wren.

How Long Does A Wren Live?

The average life expectancy of the Wren is around 2 years. However, there is evidence of individual birds surviving for far longer. One individual Wren survived for more than 7 years according to ring data.

Their survival depends on food availability, climatic conditions and predator pressure. Given favourable conditions, the Wren will generally survive for 2 breeding seasons before reaching the end of life.

How Fast Can A Wren Fly?

Wrens can reach speeds of between 15 to 28 miles per hour (24 to 45 km/h) when in flight. However, they commonly fly at around 22 mph (35 km/h).

These speeds are quite remarkable considering the size and weight of the Wren. Plus many Wrens in Europe are resident birds and don’t need to migrate over large distances.

Are Wrens Aggressive?

Wrens are generally not known to be aggressive birds, especially towards humans. However, like many small birds, they can be quite territorial, particularly during the breeding season. 

Male Wrens are highly territorial and will defend their nesting area vigorously from other males. This often involves loud singing, aggressive posturing, and sometimes chasing intruders away.

During the breeding season , they are especially protective of their nesting sites. They can exhibit aggressive behaviour towards other small birds if they perceive them as a threat to their territory.

While they are more likely to live peacefully with other bird species, they often show some aggressive behaviour if there is competition for food or nesting sites. Wrens will not usually display any aggressive behaviour towards larger bird species due to their small stature.

What Is A Wren’s Habitat?

The Wren can be seen in a large range of habitats including any area, whether cultivated or not, where there are bushes and low ground cover. These can be gardens, hedgerows, thickets, woodlands, reed beds and plantations.

Wrens can also be found in more open locations like rough pasture, moorland rocky slopes, rocky coasts and sea cliffs. They breed in Europe as far north as Norway, Finland, Sweden and Russia. And as far south as northern Spain, southern France, Italy, Sicily and southern Russia.

Wrens can also be found breeding in western Asia and as far east as Syria.

How Long Does It Take For A Wren To Build A Nest?

On average, it takes a Wren around 4 to 6 days to build a nest. The process can take longer depending on weather conditions, the experience of the male Wren and the availability of building materials.

The male Wren usually starts by choosing a suitable nesting site. They often prefer hidden locations like dense bushes, crevices, or holes in walls.

He will build a dome-shaped structure with the outer framework made from twigs, moss and leaves. Once this outer structure is completed, and the female has selected the nest of her choice, he will line the nest with softer materials like feathers, fur and fine grasses.

Interestingly, male Wrens may build several nests in different locations. The female then chooses one of these nests to lay her eggs in, often adding some of her own finishing touches. The male only lines the nest that has been selected by the female.

Eggs

Once the nest has been constructed to the satisfaction of both parents, the female will lay her eggs. This is an important time in the life cycle of the Wren as it is the beginning of a new generation of Wrens.

When Do Wrens Lay Eggs?

The breeding season for the Wren starts in late March or April. The female will lay her eggs as soon as the weather warms up sufficiently which is typically in April.

She will coincide her egg laying with the emergence of insects and other small invertebrates to ensure that her offspring have sufficient protein rich food to sustain them through the early stages of their development.

How Many Eggs Does A Wren Lay?

The female will lay a clutch of between 3 to 11 eggs with an average clutch containing 5 or 6 eggs. The number of eggs laid depends on the age, health and experience of the female.

She will typically lay 2 broods during the breeding season.

What Do Wren Eggs Look Like?

Wren eggs are white with a number of reddish-brown spots or speckles mainly concentrated at the broad end. Each egg is around 16 mm long by 13 mm wide and weighs around 1.3 grams.

How Long Do Wren Eggs Take To Hatch?

The eggs take around 14 to 18 days of incubation before they hatch. The female is solely responsible for the incubation of the eggs. The male is usually defending his territory and bringing food back for the female during the incubation period.

Chicks

Once the eggs hatch, we move onto the next important stage in the life cycle of the Wren, the chicks. Wren chicks are altricial which means they are hatched with their eyes closed and without any feathers.

How Many Chicks Does A Wren Have?

The number of chicks should correspond to the number of eggs laid. However, not all eggs hatch and not all chicks survive to the fledgling stage.

Factors like non-fertilisation, the non-development of the embryo and predation can account for significant losses in any bird population including the Wren.

But generally, 80 to 90% of the eggs will produce a healthy chick.

When Do Wren Chicks Open Their Eyes?

Wren chicks typically open their eyes when they are around 6 days old. When they first hatch the chicks are naked, blind and fully dependent on their parents for all of their needs.

Both parents feed the chicks with high protein foods to ensure they grow and develop at a rapid rate. As their eyes open and they begin to recognise the world around them, the chicks start to develop and become ready to face the challenges that will meet them outside of the nest.

When Do Wren Chicks Fledge?

The chicks typically fledge or leave the nest when they are around 15 to 20 days old. Even after fledging, the younglings still remain close to their parents who will still be feeding them and teaching them how and where to find food and avoid danger.

SEE ALSO: Blackcap Warbler Life Cycle: Nest Building To Fledging (and everything in between)

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