It may be a common sight hopping across our lawns, but don't let familiarity breed contempt. The blackbird has real charisma and some very unusual habits. In the light evenings of mid-summer, or even where street lights illuminate their breeding a...

It's not at all obvious, looking at an adult male blackbird with its black plumage and orange-yellow beak, that it is a member of the thrush family. Take a look at a female, however, and you can see the resemblance - the definite spotting on its breast makes it look a bit like a well-rounded thrush.

Unlike the song thrush, which has declined dramatically in recent years, blackbird numbers are up by about 16% across the last decade. This may in part be due to their very varied diet and the foods that they consume. Blackbirds certainly don't have food fads. In August, for example, they'll eat rowan berries. They move on to apples and blackberries during September and October, then haws in October and November. In December, holly berries are a favourite, but by the time January and February arrive, all that's left are ivy berries. The recent run of warm summers and mild winters have meant plenty of these fruits on which the blackbirds can feast.

Their berry-eating habits are a bonus for the plants. The seeds usually pass through the birds' digestive systems undamaged; indeed those that do will germinate much more quickly than others, deposited as they are in their own little pile of manure. Thus the blackbirds are an important dispersal mechanism for the trees on which they feast.

Blackbirds are not just fruit and berry eaters. At any time of year, except during severe frosts, you'll see them probing the grass for worms and grubs, and they're never afraid of coming to the bird table, or even the window, for a free hand-out.

It's probably due to their catholic feeding habits, and possibly also to their relatively large size, that blackbirds fare well in winter. Figures for the severe winter of 1962/63 show that whilst there was a 57% mortality rate in other thrushes, only about 18% of blackbirds succumbed to the cold.

The blackbird currently has a British population of about four million breeding pairs. Many more arrive here in the autumn from Scandinavia, Germany and France to enjoy our mild winters, so it's not inconceivable that there might be 20 million blackbirds in the country right now, with at least three visiting each Devon garden during the course of a day.

Although the blackbird is typically a bird of the woodland fringe, it has adapted well to garden life and benefits from the facilities that we provide, like bird table, pond, shrubbery and lawn, which provide everything a blackbird could need in a very compact space.

Blackbirds love bathing and do so with vigour in bird bath or garden pond. On really hot days in summer they enjoy basking in the full heat of the sun, opening up their wings to allow the sun's rays to reach every part, and they puff out their feathers to retain as much heat as possible. As they seem to become uncomfortably warm in the process, you'll see them with their beaks open in an attempt to lose some of that excess heat. Blackbirds can become quite confiding whilst sunbathing, almost stupefied by the effect of the heat.

Sunbathing in this way is helpful because it stimulates the preen gland at the base of the tail to produce oil, and helps its 'spreadability'. After sunbathing they'll find somewhere safe to preen, spreading the oil through their feathers and ruffling them back into position.

The blackbird's gorgeous flutey song is a real sign that spring has arrived, and it's then that the bird sings most powerfully, usually from a conspicuous position on post or tree top, to establish a breeding territory. The birds sing mainly at daybreak but they'll also sing at night, especially where there are street lights, and the lusciousness of their song can almost rival that of the nightingale. At night they don't have to compete so much with other birds who have quietly gone to roost, so their song may have a more productive effect. In winter they are far less vocal, but may sing a more jumbled collection of notes from positions in the undergrowth, a feature known as subsong.

While their song is attractive, their alarm calls can be most irritating, especially if you're a tawny owl. The naturally defensive blackbird keeps watch for unwelcome visitors, and as dusk falls it's not unusual to hear a group flapping and twittering around the edge of a wood. If so, have a closer look because it's quite possible that the birds will have discovered a tawny owl recently awakened from its daytime snooze. Having given away its position, it's not long before the sentry will be joined by all the other nearby birds to give the owl a good scolding.

Blackbirds have little to fear from the owl but their instinct is to try to chase it off, though in my experience they're rarely successful. If there are no owls about they'll probably find something else to scold; perhaps it's a local cat that gets the telling-off. Whatever the subject of their attention, it's rare that dusk approaches without a blackbird venting its anger on something.

DAVID CHAPMAN