The white-throated dipper is small and stout. It has a compact build with strong legs and a short tail. It has dark plumage, often a sooty black, that contrasts with its large snow-white bib over the breast. In Britain, the bird’s underparts beneath the bib are a rusty brown, with the same colour over its crown, extending beneath the eyes. Bill and legs are dark. Sexes are similar. Juveniles are dull grey with pale wavy bars above and dark ones below. Depending on regional variation, they may show a hint of a pale bib.
The dipper’s call is a short, hoarse “stretts” that can penetrate through the sound of rushing water, and is often given as the bird flies along a watercourse. The song is causally delivered with a soft series of alternating throaty notes.
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The dipper eats large, mainly aquatic invertebrates, some worms and small fish. Dippers swim and walk along the riverbed against the current, foraging and identifying prey by touch. They use their wings to paddle along the bottom of the river while their strong feet grip on to rocks. They will sometimes emerge from the water with caddisfly larvae and hammer them out of their casings on a rock.
Dippers are well adapted for their underwater forays. They have nasal flaps that prevent water from entering their nostrils. They can enhance their vision underwater using focus muscles that change the curvature of the lens in their eyes. Their ability to store oxygen in their blood means they can stay underwater for up to 30 seconds.
The dipper is found exclusively along the edges of fast-flowing waterways. For this reason, it favours upland regions such as in Scotland or Wales, although it can also be seen in lowland rivers in South-West England. They are present in the UK all year round.
Dippers are often seen perching on rocks and boulders mid-stream, bobbing in characteristically spasmodic fashion, then suddenly disappearing underwater. They will also swim on the surface of the river with their body low and wings open. The dipper’s short, rounded wings give it a characteristic whirring sound during its flight, which is straight and fast. The main clue that a dipper is nearby is the tell-tale droppings it leaves on rocks in the river.
Dippers breed exclusively along fast-flowing streams and rivers. During courtship displays, the male sings and runs around, posturing in front of the female while exhibiting its snowy white breast. Dippers rear their young in a concealed nest, usually under a river bank and sometimes even behind a waterfall. Pairs work together to build their nests, which will be a dome of moss and grass in a hole or crevice. Nest sites are traditional and are used by successive generations of birds. One site is said to have been in continuous use for 123 years. The female will lay a clutch of 4-5 white eggs any time between March and June. The eggs are incubated for around 16 days. The youngsters will fledge after about 3 weeks. A second clutch will be started 1o days after the first one has fledged.
The average lifespan for a dipper is 3 years; however, the oldest recorded in the UK and Ireland was 8 years and 9 months old.
Most European populations are resident, moving to lower altitude valleys in the winter. Some northern birds are partial migrants.
Given their dependence on fast-flowing waterways with clear water, dippers are vulnerable to water pollution, and habitat changes such as dam building. However, despite these threats, dippers are evaluated a species of least concern globally. In the UK they have a Amber conservation status. There are though to be anywhere from 6,000 – 18,000 breeding pairs in the UK.
Known collective nouns for a group of Dippers are as follows: