An opportunistic species, the black redstart feeds mainly on insects and larvae, as well as other invertebrates, such as earthworms, spiders and snails. In the autumn, the black redstart will also feed on fruits, berries and seeds (2) (3) (5) (10). The black redstart typically forages on the ground, sometimes digging in the earth to uncover larvae. It will also perch and make sallies to the ground, or catch passing insects in flight, as well as sometimes briefly hovering to take prey from vegetation (2) (12).
The black redstart breeds around mid-April to early July in the European parts of its range, May to August in India, and June to July in China (2) (3). The male black redstart sings intensively during the breeding season to establish and reinforce its territory (13). It is unusual among other small ground feeding passerines as it prefers high song posts, often perching 20 metres or more above the ground on natural or artificial perches, avoiding trees and tall shrubs (11).
The female black redstart builds a loose nest of dry grass, leaves and moss which is lined with hair, wool and feathers. It is usually placed in a hole, cavity, crevice or ledge among rocks or buildings (2) (3) (11), between 3 and 50 metres above the ground (11). Breeding sites are generally located in fairly close proximity to open, still or slow-moving water, such as streams, rivers or canals, or in areas of sparsely vegetated, rubbly or rocky terrain that provides the black redstart with an abundant source of insect prey with which to feed the young (11) (14). This species lays a clutch of between 4 and 6 eggs, which are incubated solely by the female for around 13 days. The black redstart may produce two broods each breeding season (2) (3) (8) (11). Both the male and female provide food for the chicks, which remain in the nest until they fledge between 12 and 20 days after hatching. The young are often flightless for several days after leaving the nest (2) (3).