The male common blackbird attracts the female with a courtship display which consists of oblique runs combined with head-bowing movements, an open beak, and a "strangled" low song.
The female remains motionless until she raises her head and tail to permit copulation.
This species is monogamous, and the established pair will usually stay together as long as they both survive.
Pair separation rates of up to 20% have been noted following poor breeding.
Although the species is socially monogamous, there have been studies showing as much as 17% extra-pair paternity.

The nominate T. merula may commence breeding in March, but eastern and Indian races are a month or more later, and the introduced New Zealand birds start nesting in August (late winter).
The breeding pair prospect for a suitable nest site in a creeper or bush, favouring evergreen or thorny species such as ivy, holly, hawthorn, honeysuckle or pyracantha.
Sometimes the birds will nest in sheds or outbuildings where a ledge or cavity is used.
The cup-shaped nest is made with grasses, leaves and other vegetation, bound together with mud.
It is built by the female alone.
She lays three to five (usually four) bluish-green eggs marked with reddish-brown blotches, heaviest at the larger end; the eggs of nominate T. merula are 2.9×2.1 centimetres (1.14×0.93 in) in size and weigh 7.2 grammes (0.25 oz), of which 6% is shell.
Eggs of birds of the southern Indian races are paler than those from the northern subcontinent and Europe.

The female incubates for 12–14 days before the altricial chicks are hatched naked and blind.
Fledging takes another 10–19 (average 13.6) days, with both parents feeding the young and removing faecal sacs.
The nest is often ill-concealed compared with those of other species, and many breeding attempts fail due to predation.
The young are fed by the parents for up to three weeks after leaving the nest, and will follow the adults begging for food.
If the female starts another nest, the male alone will feed the fledged young.
Second broods are common, with the female reusing the same nest if the brood was successful, and three broods may be raised in the south of the common blackbird's range.

A common blackbird has an average life expectancy of 2.4 years, and, based on data from bird ringing, the oldest recorded age is 21 years and 10 months.
The male common blackbird attracts the female with a courtship display which consists of oblique runs combined with head-bowing movements, an open beak, and a "strangled" low song. The female remains motionless until she raises her head and tail to permit copulation. This species is monogamous, and the established pair will usually stay together as long as they both survive. Pair separation rates of up to 20% have been noted following poor breeding. Although the species is socially monogamous, there have been studies showing as much as 17% extra-pair paternity.
The nominate T. merula may commence breeding in March, but eastern and Indian races are a month or more later, and the introduced New Zealand birds start nesting in August (late winter). The breeding pair prospect for a suitable nest site in a creeper or bush, favouring evergreen or thorny species such as ivy, holly, hawthorn, honeysuckle or pyracantha. Sometimes the birds will nest in sheds or outbuildings where a ledge or cavity is used. The cup-shaped nest is made with grasses, leaves and other vegetation, bound together with mud. It is built by the female alone. She lays three to five (usually four) bluish-green eggs marked with reddish-brown blotches, heaviest at the larger end; the eggs of nominate T. merula are 2.9×2.1 centimetres (1.14×0.93 in) in size and weigh 7.2 grammes (0.25 oz), of which 6% is shell. Eggs of birds of the southern Indian races are paler than those from the northern subcontinent and Europe.
The female incubates for 12–14 days before the altricial chicks are hatched naked and blind. Fledging takes another 10–19 (average 13.6) days, with both parents feeding the young and removing faecal sacs. The nest is often ill-concealed compared with those of other species, and many breeding attempts fail due to predation. The young are fed by the parents for up to three weeks after leaving the nest, and will follow the adults begging for food. If the female starts another nest, the male alone will feed the fledged young. Second broods are common, with the female reusing the same nest if the brood was successful, and three broods may be raised in the south of the common blackbird's range.
A common blackbird has an average life expectancy of 2.4 years, and, based on data from bird ringing, the oldest recorded age is 21 years and 10 months.
Common blackbird