THERE used to be a tradition that today was the first day of spring. I am sure that was connected with the lengthening days, the warmth that can be generated by the sun if we are lucky, the appearance of new shoots among a variety of our plant life and a few notes of bird song. In reality, of course, spring is some time ahead - there is another month or so before the new season can be officially welcomed.

Added to this obsolete idea was the notion that if today happened to be cold, it heralded a period of deeper chill coupled with a damp and miserable time. It was also said that if there was snow today, it would persist for a further 40 days; likewise, if there was rain, it would continue for 40 days or if there was sunshine, it would remain for forty days.

Weather prognostications of this kind are usually associated with a saint's day, but today's saint appears to have very little to do with English weather. It is the feast day of St Margaret of Cortona who died in 1297. She was an Italian who lived in the Tuscany region and was known, in later life, for her works of charity and her secluded lifestyle.

So far as I can see, no British saint is celebrated today but there is another ancient belief - if you see your first new born lamb today, with its head towards you, good luck may be expected! It is bad luck if it is facing away from you, but that can be countered by turning over the cash in your pocket or purse.

I have never associated herons with an ability to forecast the weather but there are one or two ancient sayings associated with this huge bird.

One is that a heron, when it soars high and particularly when it flies above low clouds, is an indication of strong winds. If it flies low, however, showery rain is forecast and if, during the evening, it flies up and down the river or backwards and forwards across a lake or open area as if looking for somewhere to rest, a spell of very severe weather may be on its way. If, on the other hand, it stands on the river bank with an appearance of misery and sadness, rain is due.

The ability of birds, animals and insects to forecast our weather is well documented and there is little doubt that, in comparison with humans, they are infinitely more sensitive to atmospheric changes. Our ancient weather-lore books are rich with sayings dating from the mists of time, most of which have resulted from the careful, long-term observations of nature by our forefathers, and I think it is fair to say much of that well-used weather-lore is surprisingly accurate.

My recent excursions into the dales and moors have revealed a surprising number of herons along our rivers and beside our lakes, and one of them even flew over our garden, probably heading for a nearby patch of inland water.

It is not difficult to identify this bird; its immense size makes it comparatively simple to spot whether in flight or standing in water, while its predominant colours of grey and white, with black wing markings, are an additional factor. It has a black line running down the front of its neck and another crossing the face and eye, with a neat. little black crest which trails from the back of the head.

In flight, it looks cumbersome and heavy, with its long neck drawn back, its slow wingbeats and its long legs stretched out behind, like a kind of rudder.

At more than three feet (almost one metre). it is indeed a large bird and more surprisingly, it nests in trees, usually in colonies where some observers mistakenly believe it is a gathering of storks.

Looking very much like a stork, the heron stands upright on long slender legs and with a long neck; it is also blessed with a very long and sharp beak which it uses to good advantage to spear fish which it swallows whole.

A quiet walk beside a river or lake will sometimes take you very close to a heron in deep concentration as it awaits a meal. It stands rock-still in the water, often with its head tucked into its shoulders and sometimes balanced on one leg but frequently almost invisible when among reeds or tall vegetation. It has endless patience, sometimes waiting for hours while staring into the water as it watches for the arrival of an unwary fish or eel, Occasionally, it may batter the surface of the water with its wings to drive fish into the shallows where it can make its selection.

It might even be tempted by a swimming mammal of some kind, such as a vole, or even a frog, snake of young bird. But once such a tempting object of prey strays within its reach, the heron will respond with bewildering speed to spear the creature with a swift plunge of its beak. It will often consume the hapless victim in one go. And it rarely misses with that downward plunge of its razor-sharp beak.

The heron is widespread throughout the British Isles, although there is some movement during the winter, often with visitors coming from Scandinavia and other parts of Europe to escape the worst of the weather.

One of the heron's less welcome habits is raiding ornamental lakes and even small garden ponds for goldfish, but it might counter this by visiting farmyards to pick off rodents and other pests.

Its nesting habits are peculiar because it often - but not always - nests in trees. The female usually builds a platform of sticks with a slight hollow in the centre and this is frequently positioned high in a tree.

Although they appear to prefer isolated localities for nesting, they will occasionally make use of trees in parkland, apparently unconcerned about the presence of humans. Sometimes, though, a heron will nest on a cliff ledge or even among reeds around the edge of a lake.

As early as February, the female will lay three, four or five eggs, and within little over three weeks the huge chicks emerge to be fed, via regurgitation, by both parents.

Herons like to nest in colonies and it is not uncommon to find several of these huge nests in one locality, but as each year goes by, the birds make use of the original nest by adding more sticks and twigs. The result is a colossal pile of what look like untidy sticks but in fact, these nests are very safe from predators, although they are liable to destruction by gale force winds.

Another of its strengths is that a heron may travel several miles on each foray for food and, once it finds a ready supply of fish, it will return time and time again - garden pond owners beware! As hunters, herons are ruthless and extremely efficient and perhaps we should be pleased that, on occasions, they turn their talents to the destruction of farmyard vermin.

Following my notes about haggs and marshy places (D&S, Feb 8), I am reminded that the words carr or carrs are also applicable to open areas of marshland, but not those which are found on the moors.

Carrs seem to be rough patches of ground more applicable to the lowlands of the dales and moors, and the word crops up in place-names. At Glaisdale, where I was born, one area of the village is called Carr End and I believe that name also appears in the Aysgarth area. There are Upsall Carrs, Lease Carr, several places known simply as The Carrs (often on the outskirts of a village) and one or two Carr Halls dotted about the county.

Canon J C Atkinson, the vicar of Danby-in-Cleveland who died in March, 1900, wrote widely about life in the moors and he maintained the word carr indicated a grove of alder trees. This was disputed by Sir Alfred Peace and Major Jack Fairfax-Blakeborough, who noted that alders were often a feature of carrs but only because those trees favour ground which is wet. It just so happens that the soil of an area called, say, The Carrs, is ideal for alder trees - and places where alder flourish are often called ellers.

I doubt if villages whose names begin with Car, such as Carthorpe, Carperby or all those Carltons, can be linked to carr. More than likely, such communities would be named after the family who first settled there, those 'cars' therefore being the remnants of someone's personal name.

And a puzzle with which to end - the Swaledale name of Carkin seems to have defied all attempts to explain its origins.