THERE is an old tradition which says that wild birds mate on the feast of St Valentine, and that the crocus comes into bloom at this time. In some parts of Yorkshire, the crocus was dedicated to this saint - although, in fact, some 52 saints share this name, while two of them share this same feast day.

This annual day of romance, which arrived on Wednesday, is also the day when countrymen of bygone times planted their new seeds, particularly broad beans.

When planting beans, they always reckoned it needed four for every one which reached maturity - one to rot and one to grow, one for the pigeon and one for the crow!

With birds being so prominent around Valentine's Day, it is not surprising that my postbag contains several interesting notes about these delightful creatures, some of which arose following my comments about the varieties which have graced our feeding station.

Beginning with a more serious note, however, one sad fact, widely reported earlier this month, is that song thrushes, mistle thrushes and blackbirds are increasingly rare on farmland; this is due to the widespread use of chemicals which destroy their sources of food, and to the destruction of their habitat like hedges and ditches, although these birds can often be found in domestic gardens.

Nonetheless, there is serious decline - figures show that 4m breeding pairs in this country 30 years ago have now dwindled to fewer than 1m. These figures complement my reference to the decline of house sparrows. During the past 20-25 years, according to research by the RSPB, their population has fallen by as much as 50pc.

New research by the Mammal Society now indicates that much of this is due not to a loss of environment or chemicals, but to the killer instincts of the domestic cat.

In just one year, Britain's domestic cats killed a staggering 275m small mammals and birds. Based on a population of 9m domestic cats, this works out at just over 30 creatures per cat per year.

These figures were calculated after a study of almost 1,000 cats in more than 600 households.

Among their mammal victims, mice were the most numerous, followed by field voles and bank voles, then shrews. Rats did not feature highly in the figures, chiefly because a rat will fight back, but it was found that domestic cats killed a wide range of animals, including rabbits, squirrels, stoats, weasels, hamsters and even bats, frogs and slow worms, as well as rarer animals like water shrews, harvest mice, yellow-necked mice, dormice and water voles.

Among the bird casualties, the house sparrow was the most numerous to suffer death from our feline friends, but there were some surprises because their catches included gulls of various kinds, jays, woodpeckers, swifts, swallows, tree creepers and goldcrests - an indication that the cat will cover a large area of countryside beyond its home boundaries.

Outings of this kind, coupled with a pet cat's ability to revert to its natural hunting and killer instincts, is a reminder that we know so little of the true face of nature. And we don't really know the truth about the secret life of our own pet cat. Just what does he or she get up to when let out of the house?

Bird nut rage

Continuing with a reference to the birds which have graced my own feeding station, I can now add longtailed tits to the list of my regular callers.

At first, we witnessed one of them who arrived somewhat cautiously, to tackle the nuts in our container, but once he had established himself, he was joined by a second and then a third. Now all three feed constantly just in front of our kitchen window and provide us with hours of joy and interest.

The interesting thing is that our longtailed tits do not fight with each other, nor do they drive away other birds. This might be due to the fact that, outside the breeding season, longtailed tits form small groups and so they are accustomed to communal life. Of further interest is that they are normally insect eaters, tackling nuts and seeds only occasionally.

A correspondent from Knaresborough tells me of his own bird feeding station which, in addition to attracting a range of garden birds such as blue tits, great tits and sparrows, has recently been visited by a blackcap.

This is a member of the warbler family, distinguished by the black cap of the male and the reddish-brown cap of the female. Normally, this bird would fly to Africa for the winter, although some do remain in England, usually in the mild south-west, consequently a visit to a northern bird table in winter is somewhat unusual.

My correspondent did comment upon the very aggressive nature of this blackcap, and I saw a similar report in a national paper, when a blackcap had visited a bird table and shown signs of unusual aggression. Bird nut rage, perhaps?

Other unusual visitors to my Knaresborough correspondent's bird table have included a goldcrest - the tiniest of birds and normally an insect eater - and also a marsh tit, a rare sight in a domestic garden. My correspondent does add that the British Trust for Ornithology organises a continuing survey into the activities of garden birds. This is the Garden Bird Watch, an important insight into the movements and behaviour of the many species which grace our domestic landscape.

Yet more correspondence about birds has come from a lady living at Carlton near Stockton. While walking near a reservoir recently, she found a dead kingfisher, but its sad demise was all the more curious because it had a small dead fish in its beak, pointing headfirst down its throat. She wonders if the bird had been suffocated by this; because there was no sign of injury to its body.

Kingfishers do eat small fish, and have a cruel manner of dealing with them. They dive into the water to catch them, then find a branch upon which they beat the fish until it dies. Then they turn it around and swallow it head first, to avoid the fins catching in their throats. A tough ending for a fish. Without seeing this particular kingfisher, I cannot say whether it tackled a fish which was too large or whether it died from some other cause. What is interesting, of course, is that a kingfisher has been sighted at all - this is another species which is increasingly rare.

During the harshness of winter many kingfishers may head for our coastal areas because tough winter conditions can sometimes restrict their supplies of food.

Search for Lizzie

On a different topic, I have received a letter from a reader at Crayke, near Easingwold, who refers to my notes about Maj Jack Fairfax-Blakeborough. He wonders if the major's loveable character, Lizzie Leckonby, was based on a woman who used to live at Carthorpe near Bedale.

He thought the major once lived at Carthorpe, to be inspired by a delightful woman who kept dozens of cats and travelled everywhere by bus. The same woman thought so much of my correspondent, that she left him £5 in her will.

The major always said that, if you went into any village in Yorkshire, you'd find a Lizzie Leckonby, and I always believed that she, and her constant protagonist, Mary Thompson, were inspired by women living at Castleton, near the major's Westerdale home.

The third character in the major's popular dialect tales was Matty Pearson but he was real. He travelled around Castleton and district with a horse and cart, selling vegetables and fruit, thus helping to blur the distinction between fact and fiction.

One day, a bus load of tourists arrived in Castleton, some of whom attempted to find Lizzlie Leckonby's house. They spotted Mattv Pearson's cart, with his name on the back, and asked him for directions to Lizzie's house. Quick as a flash and anxious to perpetuate the long-running myth, he replied: "She's doon wi' scarlet fever, so you'd best keep away or mebbe you'll git smitten.