The period between today and May 14 is known as the Ice Saints' days or sometimes the Frost Saints' days. There are four saints whose feast days occur during this period - St Mamertus (May 11), St Pancras (May 12), St Serviatus (May 13) and St Boniface (May 14) - and the reason for this unseasonal name is that very cold weather is likely to arrive around this time.

In day of old, the shepherds of the dales and moors would say, "He who shears his sheep before St Serviatus' Day loves the wool more than the sheep," although it must be said that his feast day, May 13, is generally regarded as beneficial for planting beans.

Little is known of these saints, especially in this country, and it must be said that St Pancras is not the patron saint of railway stations. The reason for the London railway station bearing his name is that it is built upon the site of the former St Pancras church.

One might wonder why these obscure saints continue to feature in our weather-lore calendar and the reason dates to 1752, when the calendar changed. Afterwards, May 11 was long regarded as Old May Eve and May 12 was Old May Day, thus elevating these saints into figures of some importance in the rustic calendar. In addition, May 14 is sometimes called Pack Rag day.

That was when farm workers left their employment to seek new work, packing their belongings into bags and trekking to their new place of work. And for those interested in saints' days, May 13 is also the feast day of St Euthymius the Enlightener, while May 15 is the feast day of St Dympna, patron saint of the insane, as well as being Buttercup day.

The latter arises from one of those wonderful old legends where a fair damsel was terrorised by a huge serpent. A gallant knight came riding by as they do, and after a terrible fight, slew the fearsome creature and rescued the damsel. Tragically, the gallant knight was fatally wounded in the process and as he lay dying, he plucked a buttercup and quoth to the maid, "Think of me when you first see a buttercup." And then he died, but no-one know where this happened.

An Easingwold correspondent has called to query the word lek as it applies to the mating ritual of cock game birds such as the black grouse, and to ask whether it has any connection with the dialect word laik which means to play. Laik, pronounced in ways varying from lark to lake, seems to be very widespread in this region, ranging from south Yorkshire well into Northumberland.

So far as lek is concerned, this name can be used for the area in which a game cock performs his mating ritual, or it can mean the courtship display itself. In the case of the black grouse, for example, several males and females will gather at dawn for a communal exhibition and they will often choose a location which has been used on many previous occasions.

Each cock bird selects his own special patch of ground where he will take up a position with his tail of black, curled feathers and straight white feathers standing erect. His wings are spread wide and droop slightly while he faces another cock bird and makes a long bubbly sound which is broken by occasional harsher notes. Fights can sometimes break out between these displaying males but for most of the time they strut around in what appears to be a threatening manner, sometimes jumping into the air.

While this performance is underway, the females pretend to be totally disinterested, wandering around the area and apparently paying little or no attention to the parading cock birds. After a suitable length of time, however, a female might decide that a particular cock bird is the hero of her dreams, and she will indicate her desire by crouching in front of him.

The word lek appears to come from Scandinavian sources - there is the Swedish lek which means sport or play, and the Old Norse leikre which means the same thing, this being similar to our dialect word laik. In some parts of the North York Moors, laik can also mean to tease someone, while laikings mean toys and other playthings. In parts of West Yorkshire, however, laik can refer to being unemployed or off work, while laik tally means to play truant.

Another term used in the moors was laiking brass which meant pocket money, or money which could be used for frivolous purposes. This was often handed out to children by their parents when they were going to the fair. Laiking about, sometimes pronounced larking about, continues to be used in many parts of this region.

I thank my Easingwold correspondent for allowing me to laik about with these words!

The bird activity in our garden is increasingly fascinating. I am writing these notes having just returned from enjoying my morning coffee out of doors, during which my wife and I were greeted to a repetitive hammering sound from within the blue tits' nest box. It sounded just like someone knocking nails into a hollow box or perhaps more like a woodpecker trying to hack its way out.

It was neither. It was a pair of blue tits carrying out an examination of a possible nesting site. Being scrupulously clean birds, they dislike mites in their nesting sites and so they peck fiercely at the wood so that if any insect pests are lurking within the seams or cracks, they will be shaken out or terrified into fleeing for their lives. In this way, the tits ensure they have a clean place in which to built their nest and raise their brood. Having seen tits enter our nest box over the past few weeks, with nothing further developing during those early stages, it does now seem as if the nest box has been given their approval - along with a spring clean just like anyone occupying a new home in fact. We await developments with interest.

The second piece of fascinating bird life involves our pied wagtails. Having spent time in the garden, they are now building a nest in the ivy directly outside our lounge window, or perhaps they are repairing their old nest. I suspect the latter is the case for a sneak look at the old nest does suggest it has been subjected to some intricate maintenance work.

The curious thing is that my reference books suggest that the female builds the nest. In our case, both birds are doing so but how does one distinguish the male from the female? One of my books says the male is more black than his mate; she has a greyer colouring, although another book says both birds are identical. Further checks do indicate the female is slightly more grey along the back than her companion, although there is a European variety whose backs are rather more grey than black. In our case, I am sure the one in the sharp black and white suit is the male, with his partner sporting more gentile grey plumage on her back.

The unexpected arrival of these wagtails, and their return to the very nest they used last year, makes me wonder if wagtails mate for life, or whether either of these joined us last year and has since found a new companion. None of my references, however, suggest that wagtails return to their former nests. It all means we have some interesting visitors to the garden and our own sojourns to the patio are, once again, to be undertaken with these nesting birds very close at hand. I hope our routine family activities - and our boistrous grandchildren - do not disturb them.

The dawn chorus has not been so noticeable this year. In the past, we have been roused at dawn by hundreds of birds singing in unison. Chaffinches would dominate the music, with blackbirds, thrushes and others in the background. This year, our dawn chorus has sometimes comprised a single blackbird whose music was divine, although our evenings have been brightened by a song thrush singing from the top of a silver birch. Sometimes, he was joined by the blackbird. Sheer bliss!