The blackbird is the most numerous breeding bird in the British Isles, with a population of around 6 million pairs.
The highest breeding densities are to be found in small urban parks and residential areas.
The European population has been estimated at between 38 and 55 million pairs.
The only European country with no breeding blackbirds is Iceland; small numbers do occur there in the winter.
The reason for its success is its adaptability, for it is equally at home in a town park or suburban garden as it is in a remote Welsh wood.
Blackbirds are what is known as sexually dimorphic, which means that the plumage of the female is completely different from that of the male.
The song of the blackbird is arguably the most beautiful and best-loved of any British bird, as well as being the most familiar.
The first blackbird song of the year can usually be heard at the end of January or early February, though urban birds often start earlier.
Studies have shown that the first birds to sing are cocks that were hatched the year before. The older birds do not start singing until well into March.
Blackbirds typically like to sing after rain.
The song period continues well into the summer, but it is unusual to hear sustained song much after the middle of July.
The song Sing a song of sixpence, a pocket full of rye, four-and-twenty blackbirds, baked in a pie was actually a coded message used to recruit crew members for the notorious 18th-century pirate Blackbeard.
The majority of English blackbirds seldom move any distance from where they were hatched.
British birds are joined in winter by large numbers of migrants from Europe, mainly Scandinavia, the Baltic States, Russia and Germany.
The most common causes of death for ringed blackbirds are cats and cars.
It takes a pair of blackbirds between 11 and 14 days to make a nest. Most of the work is done by the female.
It is only the female that incubates the eggs, but the male helps feed his offspring.
Scottish blackbirds are usually two weeks behind their English counterparts when it comes to nest building and egg laying.
Blackbirds have been successfully introduced to south-eastern Australia and New Zealand.
Attempts to establish blackbirds in New York and Oregon in the 19th-century both failed.
The oldest ringed blackbird recovered was over 20 years old.