Ann Duff, of South Godstone in Surrey, has told me of an unfortunate experience with a family of blackbirds that had a happy ending. Hearing a commotion from the laurel hedge where their nest was situated, she rushed out and averted a calamity by chasing away a pair of magpies. The nestling blackbirds had prematurely fled the nest and were cheeping loudly nearby. She tried returning them to the nest but they were soon out again. There was no more she could do and the future of the brood looked bleak. That seemed to be the end of the story but over the next few days, both parent blackbirds were seen feeding healthy fledglings. At least two of the brood had survived the magpies' onslaught.

It is distressing if you accidentally disturb a nest of nearly full-grown baby birds and they jump out of the nest but this is a valuable safety drill. If a predator, such a magpie, stoat or squirrel, should find them, they are all surely doomed. But, if they leave the nest and scatter, there is a chance that one or more will escape detection and eventually be reunited with their parents.

In this instance, two young birds had survived and Ann Duff noticed that one was being fed by the female blackbird and the other by the male. In blackbirds, robins and a few other species, the brood is sometimes split between the parents. Each adult feeds only certain fledglings and ignores the others, while the fledglings learn to beg for food only from their 'own' parent. This behaviour may be another way to avoid the loss of the entire family.

Followed up on 18 August 01

A note last month on the blackbird’s care for its young after they leave the nest resulted in the question of the chances of survival of these young birds. This is a very difficult time in the life of any bird. Wing and tail feathers are not yet fully-grown and, while the rudiments of flight are instinctive, manoeuvring has to be perfected through practice. It is also vital that the newly-fledged youngsters maintain contact with a parent so that they will continue to be fed while they learn to forage for themselves.

In one study of garden blackbirds, each pair produced an annual average of four fledglings that left the nest. Fewer than two of these survived to the following spring, but this was more than adequate because less than one bird was needed to replace the deaths among adults. However, mortality will vary from place to place and year to year. A spell of dry weather can be a killer for young blackbirds because insects and worms stay underground where the birds cannot find them.

In the past, blackbirds have been found to bring off more young in suburban gardens than in woodland. This is rather surprising because some other birds are known to do better in the richer woodland environment. The situation could have changed in recent years as the numbers of suburban predators in the form of cats and magpies, and motor traffic, increase. Blackbirds, like many common species, are now generally in decline.