Dunnock

About

The Dunnock, also known as the Hedge Accentor or Prispolone in Italian, is a small passerine bird found throughout temperate Europe and into Asia. It is a rather inconspicuous bird, often overlooked due to its subtle brown and grey plumage, but it is well-known for its complex and variable breeding strategies, including polyandry and polygynandry.

Size & lifespan

Length

13-14.5 cm

Wingspan

19-21 cm

Weight

16-25 g

Lifespan

2-3 years (up to 9 years recorded)

Diet

Omnivore (primarily insects and spiders in summer, seeds and berries in winter)

Physical characteristics

Plumage

Adults have a streaky brown back and wings, a grey head and breast, and a buffy-brown flank with fine streaking. The throat is a paler grey. The undertail coverts are buffy-white. The overall impression is of a small, rather plain, sparrow-like bird, but with a finer bill and more upright posture.

Beak shape

Slender, pointed, dark grey to blackish bill, typical of an insectivorous/granivorous passerine.

Eye color

Dark brown.

Leg color

Reddish-brown to brownish-orange.

Distinguishing features

Its most distinctive feature is the combination of a grey head and breast with a streaky brown back, and its characteristic shuffling, 'mouse-like' movements when foraging low in vegetation.

Juvenile appearance

Juveniles are browner overall than adults, with a streaky brown head and breast, lacking the distinct grey coloration. They have a scaly appearance on the back and breast due to pale feather fringes.

Seasonal changes

There are no significant seasonal plumage changes. The plumage remains consistent throughout the year, though fresh plumage after the post-breeding moult may appear slightly richer in colour.

Sexual dimorphism

Males and females are virtually identical in plumage, making them difficult to distinguish visually in the field. Males may be slightly larger on average, but this is not a reliable field mark.

How to identify

1. 1

   Plumage

   Look for the combination of a plain grey head and breast contrasting with a streaky brown back. This grey-brown pattern is key. No strong facial markings or wing bars.

2. 2

   Size and Shape

   Small, rather dumpy passerine, slightly smaller and more slender than a House Sparrow, with a relatively long tail and a fine, pointed bill.

3. 3

   Behavior

   Observe its foraging style: a characteristic shuffling, 'mouse-like' movement low in dense vegetation or on the ground, often flicking its tail. It is generally shy and keeps to cover.

4. 4

   Song

   Listen for its distinctive, rapid, high-pitched, and somewhat 'tinkling' warble, often delivered from a hidden perch or the top of a bush.

5. 5

   Habitat

   Often found in gardens, parks, hedgerows, and woodland edges where there is plenty of dense undergrowth.

Habitat & range

Biomes

Temperate forests, woodlands, scrublands, hedgerows, gardens, parks, and urban green spaces.

Geographic range

Widespread across Europe, from the Atlantic coast eastwards through Russia to the Ural Mountains. Also found in parts of the Middle East and North Africa. Introduced to New Zealand.

Elevation range

Sea level up to 2,000 meters in some mountainous regions, but typically found at lower elevations.

Preferred environments

Dense undergrowth, thickets, hedges, shrubbery, and areas with good ground cover. They prefer habitats with a mix of open ground for foraging and dense vegetation for cover and nesting.

Behavior

Activity time

Diurnal.

Feeding habits

Forages primarily on the ground or low in vegetation, often shuffling and creeping 'mouse-like' through dense cover. Diet consists mainly of insects (beetles, ants, flies, caterpillars) and spiders during the breeding season. In winter, they switch to seeds (especially from grasses and weeds) and small berries. They will also visit bird feeders for seeds and crumbs.

Social behavior

Generally solitary or found in pairs during the breeding season. Outside of breeding, they can be seen singly or in small, loose groups. They are known for their complex mating systems, which can include monogamy, polygyny (one male, multiple females), polyandry (one female, multiple males), and polygynandry (multiple males and females in a communal breeding group).

Flight pattern

Flight is typically short, low, and undulating, often between patches of dense cover. They are not strong or sustained fliers.

Migration pattern

Northern and eastern populations are migratory, moving south and west for the winter. Western and southern European populations are largely resident or undertake short-distance movements. British and Irish populations are mostly resident.

Territoriality

Males defend territories during the breeding season, often with complex interactions due to their varied mating systems. Females also defend territories, particularly against other females in polyandrous systems.

Breeding & reproduction

Breeding season

March to August, with peak activity from April to June. Can raise 2-3 broods per year.

Nesting habits

The nest is a neat, cup-shaped structure built by the female, typically low down in dense vegetation such as a hedge, bush, or conifer. It is made of moss, twigs, and roots, lined with finer materials like hair or feathers.

Clutch size

3-6 eggs

Egg description

3-6 (typically 4-5) eggs per clutch. The eggs are a distinctive bright, glossy blue, sometimes with a few faint reddish-brown speckles, but usually unmarked.

Incubation period

12-14 days, primarily by the female, though males may assist in polyandrous systems.

Fledging period

10-14 days after hatching. Young leave the nest before they can fly strongly.

Parental care

Both sexes feed the young, but the level of male involvement varies greatly depending on the mating system. In polyandrous systems, multiple males may feed the same brood. Females often do the majority of the incubation and initial brooding.

Where to find

Field tips

1. Be Patient and Quiet. Dunnocks are often shy and inconspicuous. Sit quietly near dense cover and wait for them to emerge to forage.
2. Look Low. They spend most of their time foraging on the ground or very low in vegetation. Focus your attention on the base of hedges and bushes.
3. Listen for the Song. Their distinctive song is often the first indication of their presence, even if they are hidden from view.
4. Check Bird Feeders. In winter, they may visit ground feeders or feed under hanging feeders, picking up dropped seeds.

Similar species

Quick facts

Family:

Prunellidae (Accentors)

Diet:

Insects, spiders, seeds, berries

Habitat:

Gardens, hedgerows, woodlands, scrub

Conservation Status:

Least Concern

Distinguishing Feature:

Grey head/breast, streaky brown back, 'mouse-like' foraging

Fun facts

• Dunnocks are famous for their complex and varied mating systems, which can include monogamy, polygyny, polyandry, and polygynandry, often within the same population. This makes them a fascinating subject for behavioral ecologists.
• Despite their plain appearance, their social lives are anything but simple. Females often mate with multiple males, and males may help raise broods from multiple females, leading to intricate parental care arrangements.
• The Dunnock is a common host for the Cuckoo (Cuculus canorus) in Europe, which lays its eggs in the Dunnock's nest, relying on the Dunnock to raise its young.
• Their scientific name 'Prunella' comes from the Latin 'prunus' meaning 'brownish', referring to their plumage, and 'modularis' refers to their song, which is often described as 'modulating'.

Scientific classification

Kingdom

Animalia

Phylum

Chordata

Class

Aves

Order

Passeriformes

Family

Prunellidae

Genus

Prunella

Species

Prunella modularis

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