IN the last few weeks one of Britain's most graceful and beautiful birds has started to arrive on our shores after undertaking a mammoth journey from the equatorial regions of Africa.

Swallows are fantastic fliers and have evolved to a near perfect aerodynamic design.

Despite our best computer-designed modern aircraft, which cost millions of pounds, we would be hard pressed to beat the natural design of the swallow.

Their long, slender wings and distinctive long, forked, tails give them a beautifully streamlined shape. This gives the birds a wonderful turn of speed and, with a twist of the tail feathers, they can weave their way through the sky with outstanding agility and grace, which aerobatics teams, such as the Red Arrows, could only dream about.

I always enjoy watching the aerobatics show put on by these birds. They like the open pastures, particularly ones that are a bit wet, as it is here that the swallow finds its food - flying insects - which they hunt on the wing.

The aerobatics always seem to be best around mid-morning, which might be due to the facts that the insects are usually lower in the air column at this time of day and, as the swallows hunt, they are then much more at eye-level.

If the meadowy area has a small pool, you may be lucky enough to witness the even more spectacular sight of the swallows swooping low down over the surface of the pool to scoop a mouthful of water.

It is quite an alarming thought that the swallows are attracted to England and are prepared to fly the vast distance from Africa because of the abundance of flies our country (and others in Western Europe) has.

This food is what the swallow needs during the few weeks it will take to build its nest from mud and grass and line it with soft feathers, and to rear its brood of young. Swallows quite like buildings as nest sites, so a few of us will be lucky enough to have a grandstand view of the swallows raising a family.

Into these nests a pair of swallows will lay four to five eggs, which the birds will incubate for up to 20 days before the young hatch. The hatchlings will then spend a further 20 or so days in the nest, being fed a near constant stream of insects by its parents before taking to the skies and fending for themselves.

Come September, as our summer fades, the swallows begin their journey back to Africa to bask in the warmth of the African sun, away from the chill of our winters and our very poor supply of winter insect food.