The white-throated dipper is closely associated with swiftly running rivers and streams or the lakes into which they fall. It often perches bobbing spasmodically with its short tail lifted up on the rocks around which the water swirls and tumbles. It acquired its name from these sudden dips, not from its diving habit, though it dives as well as walks into the water. It flies rapidly and straight, its short wings whirring swiftly and without pauses or glides, calling a shrill
zil, zil, zil. It then either drops on the water and dives or plunges in with a small splash. From a perch, it walks into the water and deliberately submerges, but it cannot defy the laws of
specific gravity and walk along the bottom. Undoubtedly when entering the water, it grips with its strong feet, but the method of progression beneath the surface is by swimming, using the wings effectively for "flying" under water. It holds itself down by muscular exertion, with its head well down and its body oblique, its course beneath the surface often revealed by a line of rising bubbles. In this way, it secures its food, usually aquatic
invertebrates including
caddis worms and other aquatic insect
larvae,
beetles,
Limnaea,
Ancylus and other freshwater
molluscs, and also
fish and small
amphibians. A favourite food is the small crustacean
Gammarus, an
amphipod shrimp. It also walks and runs on the banks and rocks seeking terrestrial invertebrates. Dippers may be preyed on by predatory fish such as
brown trout, although only one case has been recorded for this species unlike in
American dipper. The winter habits of the dipper vary considerably and apparently individually. When the swift hill streams are frozen, it is forced to descend to the lowlands and even visit the coasts, but some remain if water is still open.
Breeding White-throated dippers first breed when they are one year old. They are monogamous and defend a territory. The nest is almost invariably built either very near or above water. It is often placed on a rocky ledge or in a cavity. Human-made structures such as bridges are also used. The nest consists of a dome-shaped structure made of moss, grass stems, and leaves with a side entrance within which is an inner cup made of stems, rootlets, and hair. Both sexes build the main larger structure, but the female builds the inner cup. The eggs are laid daily. The clutch can contain from one to eight eggs but four or five are usual. The eggs are smooth and glossy white and are with a calculated weight of . They are incubated by the female beginning after the last or sometimes the penultimate egg has been laid. The male brings food to the incubating female. The eggs hatch after around 16 days and then both parents feed the altricial and nidicolous nestlings. For the first 12–13 days, they are brooded by the female. Both parents remove the faecal sacs for the first 9 days. The chicks fledge at around 22 days of age, but the parents continue to feed their young for another week, but feeding can continue for 18 days. If the female has started a second clutch, then only the male parent feeds the fledglings. One or two broods are reared, usually in the same nest. When disturbed, the young that hardly feathered will at once drop into the water and dive. The maximum recorded age of a white-throated dipper from
ring-recovery data is 10 years and 7 months for a bird ringed in Finland. Within the United Kingdom and Ireland, the maximum age is 8 years and 9 months for a bird ringed and recovered in
County Laois, Ireland. ==Dippers and humans==