Dunnock

The Dunnock is a small grey-and-brown bird about the size of a House Sparrow: about 14 cm long and about 21 g. Look for a slate-grey face, throat and breast, a brown crown and cheeks, and a warm brown back finely streaked blackish. The flanks are pale brown with dark streaks, and the belly paler. Up close, the bill is thin, pointed and blackish, the eye reddish-brown and the legs pinkish to reddish-brown.¹

The bill is the quickest check. A Dunnock's is fine and pointed, suited to insects and small seeds; a sparrow's is short and chunky. Dunnocks behave differently too: they creep and shuffle about low down, alone or in pairs, often flicking their wings, while sparrows hop about in groups.²

BTO measurements of live adults put most between 18.6 and 24 g.³

Males and females look the same. A female is a shade less richly coloured, with a browner head and a less heavily streaked back, but the difference is too slight to rely on. In BTO measurements males average slightly longer wings, while both sexes weigh the same. The bird singing from the top of a bush in spring is usually a male.

Young Dunnocks are browner and buffer than adults, with little of the grey, and their head and underparts are heavily streaked. A young Robin can look similar, but it is speckly brown all over rather than streaked.⁴

House Sparrow. The bird most often confused with a Dunnock, especially a female House Sparrow. She has a plain pale chest, a pale stripe behind the eye and a short, chunky bill, and sparrows go about in groups. The likeness gave the Dunnock its old name, hedge sparrow, but it is an accentor: the only one in the UK. Side by side, with photos: Dunnock or House Sparrow?

Wren. A Wren is far smaller, 9 to 10 cm, and almost round, with a short tail often cocked up, a pale stripe over the eye and finely barred wings. Its song is very loud and ends in a trill.

Young Robin. A juvenile Robin is speckly brown all over; a young Dunnock is streaked rather than speckled.

For much of the year Dunnocks are easy to overlook, but males sing from the top of a bush or tree. The song is a short, high, squeaky warble of 2 to 4 seconds, full of trills, and sometimes surprisingly loud. Most singing is in the first half of the year, and Dunnocks are part of the dawn chorus from March to May.

Each male has 10 to 15 phrases that he mixes into different songs, repeating one several times before switching, and neighbouring males share songs, which gives local dialects. Females sometimes sing when attracting a mate, and young birds start singing in their first autumn.

The call is a thin, high "tseep", used to keep in touch outside the breeding season; a louder, higher version is the alarm. Listen to recordings: Dunnock song and calls.

Dunnocks live across Britain and Ireland all year. In the last national atlas they were found in 93% of the UK's 10-km squares in winter, absent only where there are no trees in the Scottish Highlands and from some of the Outer Hebrides and Northern Isles. Numbers are highest in lowland England and in the south and east of Ireland.

What they need is dense, low cover: gardens with shrubs and hedges, parks, hedgerows, scrub and woods with a thick shrub layer. In BTO surveys they are found most often around villages, and they are at home in small town gardens.

That lowland life is unusual. In western Europe, Britain included, Dunnocks live mainly in the lowlands, but further north and east they are birds of mountain scrub and northern forests, up to 2,700 m in north-eastern Türkiye. The move into lowland gardens, hedges and farmland is unique in the accentor family.

Watch the ground under shrubs and along the edge of a flower bed or hedge: a Dunnock creeps about there like a small brown mouse, flicking its wings. In spring, listen for the squeaky song and check the tops of bushes. Under hanging feeders, it is often the bird picking up spilt seed. After breeding, in late summer and early autumn, Dunnocks skulk more and are harder to see.

Not in Britain. British, Irish and French Dunnocks are mainly sedentary, and local birds rarely move more than 30 km; the Dunnocks in your garden were very likely born within a few kilometres.⁵

Further north and east it is different. Dunnocks from Scandinavia, Russia, Poland and northern Germany migrate south-west from August to November, to winter around the Mediterranean, in Türkiye and the Middle East, and return from February to April. A few pass through Britain, turning up on islands such as Fair Isle where Dunnocks do not usually breed. A young bird ringed at Mandal, Norway, on 24 September 2000 was caught on the Isle of May, Fife, three days later, 643 km away.⁶

Mostly insects and spiders, picked from the ground. A Dunnock forages under bushes and hedges, hopping and picking, sorting through leaf litter and now and then probing the soil. Beetles and spiders make up much of its diet, with flies, bugs, springtails, caterpillars, small snails and earthworms.

In winter it switches to seeds. In Britain, seeds made up 90% of Dunnock droppings by volume in February; by April, invertebrates have taken over again.¹ Nettle, dock, grass and other small weed seeds are typical; in one Shropshire hedgerow study, nettle was the main seed.⁷ Winter is hard work: in January a Dunnock may spend 94% of its time feeding, against 54% in May.

Dunnocks visit gardens with feeders, but mostly to pick up what other birds drop; they are timid at feeding stations and rarely feed on raised platforms. The RSPB names small seeds as a food that attracts them.⁸

Follow the RSPB's current advice: put out seed only from November to April, in hanging feeders rather than on bird tables or trays, and clean them every week. Disease can spread through food lying on the ground under feeders, so clear old seed and droppings from beneath them too.⁹ Thick shrubs and hedges matter as much as food: they give Dunnocks cover to feed under and places to nest. More: what Dunnocks eat and how to feed them.

Dunnocks nest low in thick cover: a dense shrub, hedge or bush, sometimes ivy on a wall, between about 0.5 and 3.5 m up. The female builds a cup of twigs, stems, roots, grass and moss, lined with hair or wool, and usually lays 4 or 5 blue eggs.

In Britain the first eggs are laid on 27 April on average, anywhere from early April to mid-June, and most pairs raise two broods, sometimes three. The female incubates for 14 to 15 days, and the chicks leave the nest at 12 to 14.5 days old.

Who feeds the chicks depends on who mated with the female (see behaviour, below). In a long study in Cambridge, 59% of broods were fed by the female and one male, 33% by the female and two males, and 8% by the female alone.

Dunnocks are one of the Cuckoo's main hosts, though only about 2% of UK nests are taken over. A Cuckoo's egg looks nothing like a Dunnock's blue one, yet Dunnocks rarely throw it out, which suggests they are a fairly recent host. More detail: Dunnock nests, eggs and young.

The Dunnock's plain looks hide a mating system that has been studied in great detail. Both males and females hold territories, which is unusual for a songbird, and the arrangements vary. In the Cambridge study, of 254 breeding arrangements, 42% were simple pairs, 30% were one female with two or more males, 24% were groups of two or three males sharing two or three females, and 4% were one male with two or more females.¹

Where two males share a territory, one is dominant. He follows the female closely, guarding her for as much as 40 minutes an hour, while the other waits for his chance. The female encourages the second male, and sometimes slips away to mate with him.⁵

Before mating, the female crouches, quivers and lifts her tail, and the male pecks at her cloaca, sometimes for minutes, until she ejects sperm from earlier matings. It improves his chance of fathering the chicks.

Why mate with both? A male helps feed the chicks in line with his share of the matings, so by mating with both males a female can get both to help. In Cambridge, a successful brood fed by the female and two males produced about 3 fledglings, against 2.4 with one male and 0.8 with the female alone.

Dunnocks flick their wings as they shuffle about; one of their old folk names is Shufflewing. When rival males meet, the flicking becomes a display, with loud calling and chasing.²

Outside the breeding season most Dunnocks keep to themselves, feeding alone, or in small groups where food is plentiful. They are low in the pecking order at feeders, and Robins sometimes turn on them, perhaps because of their similar shape, perhaps as competitors.

A Dunnock that survives to breed typically lives about 2 years, and first breeds at a year old. About 47% of adults survive from one year to the next, and about 35% of young birds survive their first year.³

Nests are the weak point. In the Cambridge study about 30% of nesting attempts were lost to predators, among them cats, crows and mustelids (the weasel family). Hard winters can kill many too, and when food is short the dominant birds, such as adult males, feed first.

Much longer, occasionally. The record for a Dunnock ringed in Britain and Ireland is 10 years 7 months 23 days: a bird ringed in its first year at Sandwich Bay, Kent, in September 2001 and caught there by a ringer in May 2012.¹⁰ The European longevity list, which estimates each bird's age, includes a Danish Dunnock found dead at 20 years 10 months, far older than any other Dunnock on it (the next is 12 years 4 months).¹¹

The Dunnock is on the UK Amber List. UK numbers fell substantially from the mid-1970s to the mid-1980s and are 43% lower than in 1967.³ Since 1995 the population has changed little overall (up 5%, not a significant change), but it fell by 14% between 2014 and 2024, and by 17% in England.¹²

It is far from rare: there were about 2.5 million territories in the UK in 2016, and it is found almost everywhere. The likely causes of the decline are less winter food on farmland, especially in the "hungry gap" of February and March, and in woods the loss of the shrub layer as the canopy closes and deer browse the undergrowth. Worldwide it is of Least Concern.