The dunnock (Prunella modularis) is a common bird of gardens, woods and parks, familiar to many people still under its old name of hedge sparrow. The name is slightly misleading as, while the bird does indeed frequent hedgerows, it is not related to sparrows. Dunnocks belong to a family known as accentors, small ground and scrub-dwelling birds that hop around in a characteristically crouched posture. Both sexes are similar in appearance, being predominantly brown with a striated back and belly, and with a grey head and noticeably brown eyes. Young birds are more boldly streaked with dark brown or black, these marks also extending to the head and neck, a feature not found on the adults. Dunnocks resemble robins in their habits and many people still confuse the young of the two species. The song of the dunnock is nowhere as melodic as that of the robin, consisting of a loud, clear but tuneless series of tinkling notes, often delivered from the top of a bush or a prominent branch of a tree. However, the birds sing this ditty throughout the year, and it is often the only birdsong to be heard during the otherwise dull days of late autumn and winter.
Although a common bird in the UK, only recently have studies shown that the dunnock has an interesting domestic arrangement. Although the pair-bond between the birds appears strong during the breeding season, females will often court another male and mate with him. This ensures that her chicks – whichever partner actually sires them – will receive an adequate supply of food from both males. The nest is hidden in a hedge or shrub and contains up to five pale blue eggs. There can be up to three clutches laid in a season, the first appearing in March or April. Incubation takes about two weeks with the female taking sole charge of the brooding. The young are fed by both sexes and fledge after some 12 to 14 days. The dunnock is primarily an insect feeder although small seeds often form part of the bird’s diet as well.
In the south of England, the dunnock is the principal host of the cuckoo (Cuculus canorus). Although cuckoos also parasitise the nests of meadow pipits, and match their eggs to those of that host, they rarely produce blue eggs to match those of the dunnock. This does not seem to stop dunnocks becoming unwitting foster parents to the much larger cuckoo, and faithfully rear the interloper as their own young. The cuckoo chick has a much greater appetite than the young dunnocks so, for this reason, after it hatches the cuckoo chick evicts the dunnock eggs or chicks from the nest to remove the competition for food.
The dunnock is found across the whole of Europe, and parts of western Asia. It occurs throughout the UK and republic of Ireland, where it is a resident, but in the northern part of its range, it is a migratory bird.
In Britain, the dunnock can be seen almost anywhere in the lowlands, in gardens, parks, on heaths and in woodlands. It prefers habitats with some areas of cover as the bird is rather shy in behaviour. In other parts of Europe, dunnocks are found also in spruce woods and upland forests.
The dunnock is classified as Least Concern (LC) on the IUCN Red List (1). It receives general protection under the Wildlife and Countryside Act (as amended) in the UK. Included in the Birds of Conservation Concern Amber List (medium conservation concern).
Although the dunnock appears to be an abundant and familiar bird, figures compiled by the British Trust for Ornithology show that in the decade from mid the 1970s, populations fell by nearly 50 percent. This was particularly true of woodland dunnocks, and the cause is still unknown. However, the populations have stabilised and there are signs of a slight recovery in recent years.
While the dunnock remains a relatively common bird, recent studies have shown that populations in woodland habitats are at risk. Many of the UK’s once common birds have declined drastically in the last 30 or 40 years, many as a result of increased agricultural pressure. Although the dunnock is a bird that seems adapted to survive in a variety of habitats, the pressures of our increasing demand for urban and industrial development could still prove damaging.
Recently, wildlife-friendly gardening techniques have become more popular in both rural and urban environments. So long as we provide our garden birds with a healthy balance of wild plant and insect food, there is no reason why our still familiar species such as the dunnock cannot maintain their numbers and continue to gladden us with their modest but cheerful winter songs.
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