The Dunnock

About

The dunnock takes its name from the English word dun, meaning greyish brown. ‘Ock’ is from Latin, meaning one who sings with another. Dunnocks are predominantly brown, from afar, but rather more striking when seen close up. Sometimes – erroneously – called a hedge sparrow, the dunnock is not a sparrow. Although they look similar from a distance, the dunnock has a much thinner and more pointed beak. Sparrows meanwhile have a broad and powerful looking beak. And dunnocks are usually seen in pairs, whereas sparrows tend to flock together in noisy groups.

Dunnocks can sometimes be found in gardens searching for insects and other invertebrates in the leaves beneath bushes. They are also found in areas of woodland, including the nature reserve I frequent. Following a decline in numbers of around a third during the 1970s and 80s, dunnocks were placed on the Birds of Conservation Concern amber list. Although numbers are increasing slowly, the dunnock remains a conservation concern.

Life

Dunnocks have a complex social structure. Both female and male birds have their own territories, with the male territory being slightly larger. Some males share a territory, between a dominant ‘alpha’ male, and another ‘beta’. The less dominant bird gains access to the territory through persistence, and will as a result have (limited) access to females. The males team up to defend their territory from intruders. They also have bouts of singing together to mark their ownership of the area.

Although some dunnocks have monogamous pairings, many females prefer a polyandry relationship with two males, so the alpha/beta set up suits them. This is rare among avians, with less than one per cent of bird species thought to have polyandrous systems.

Mating with the beta male is not guaranteed though, as the alpha spends up to 40 minutes of every hour protecting ‘his’ female. However, the female will create opportunities to elope with the beta dunnock, and encourage him to mate with her. This behaviour helps the female when raising the brood. After several pairings, male birds will join the female in feeding the young. By having mating sessions with both alpha and beta, the female dunnnock secures ongoing parenting support from them both.

Cuckoos

The dunnock nest is a popular target for cuckoos. Individual female cuckoos focus on a single host – robins, pied wagtails, and meadow pipits are popular. Each cuckoo inherits their designated host from their mother. Cuckoo’s eggs have evolved to match their allocated host’s as closely as possible. A 2014 study found that some birds have countered this by evolving distinct patterns on their eggs, to enable them to tell them apart from cuckoos’ eggs. Once spotted, a cuckoo’s egg is ejected from a nest, before the chick hatches and destroys the host bird’s young. There is, in effect, an ongoing battle of egg disguising between cuckoos and their hosts.

Although the cuckoo’s egg is markedly different in colour to the dunnock’s, the dunnock does not appear to be able to differentiate. This suggests that dunnocks are a comparatively recent choice of host, and have yet to enter the evolutionary battle of egg changing behaviour. That the cuckoo’s egg is so different to the pale blue of the dunnock’s suggests in turn that the cuckoo has yet to evolve a mimic pattern.

Dunnocks raise two to three broods a year, making them a good target for the cuckoo, which is on the Conservation Red List.

Finally

Dunnocks and cuckoos were mentioned by Shakespeare in King Lear (1606), where he wrote ‘the hedge-sparrow fed the cuckoo so long’. Although the date feels like an awfully long time ago, in evolutionary terms, it is very recent. Changes through evolution take thousands, even millions of years. Cuckoos were part of Ancient Greek mythology* so have been cuckooing for a while.

An earlier mention (although again, recent in evolutionary terms), was in 1382 in Chaucer’s poem ‘The Parlement of Foules’. Here the narrator chastises the cuckoo as ‘mordrer of the heysugge’. Heysugge is the Old English word for hedge sparrow, or more correctly, dunnock.

Owing to its song, the dunnock is sometimes known as the Irish nightingale. The happy daytime song is replaced by a more plaintive refrain at night. People believed this to be the cries of the souls of unbaptised babies searching for their parents.

Dunnock singing at the nature reserve (6 March 2024)

This led to another Irish tradition. The dunnock’s eggs were regarded as charms against witches’ spells when hung along the hob. They were especially good for keeping spirits from coming down the chimney.

Bring dunnocks to your garden by leaving the grass and wildflowers to grow, in turn attracting insects. Dunnocks are shy birds, and prefer to stay out of sight if they can. Leave seed, crushed peanuts and suet pellets on the ground beneath bushes. Do your best to ensure that this is out of line of direct predatory access to other garden visitors.

*Cuckoos were the sacred messengers of spring, the season in which Hera was wedded to Zeus