ONCE the clocks have been changed, we are ready to Spring forward into the countryside!

Apart from the obvious fact that the April countryside around Bolton will see an increase in birdsong and the number of flowers in bloom, there are other signs to look out for.

Early butterflies emerge to warm their wings in the first shafts of sunlight. Two species to look out for are the small tortoiseshell, which is always common, and the peacock, which is certainly on the increase in our area.

Both these butterflies hibernate as adults and this means that they are on the wing early in the Spring. Like many insects, these butterflies survive the Winter because they have a substance called ethylene glycol in their blood - we know this compound as anti-freeze!

Other hibernators to emerge during April are hedgehog and the bats. You can help hedgehogs by putting out peanuts (not salted!) in your garden and they will also welcome dog food. They do not like fishy food, and bread and milk can be lethal to hedgehogs.

The most common species of bat in the Bolton area is the pipistrelle, but the phrase "blind as a bat" is not quite true. Bats do have very tiny eyes but they cannot see so well as most mammals and they are only able to appreciate whether it is dark or light. This obviously tells them when to come out to feed.

Bats have no need of eyes to hunt because they have a wonderful echo-location system very similar to modern radar. All scientists accept that the bat's system is much more sophisticated than any system that we humans have been able to invent!

One fascinating discovery recently made is that the insects on which the bats feed are not stupid.

Many moths have developed high-pitched sounds which "jam" the bat's radar system. Up there, in among our house eaves and above the trees, a real dog fight is going on.

Scientists have invented detectors which pick up the sounds of a hunting bat and also the sounds made by the jamming device of the moths.

It just goes to show that there is nothing new under the sun!

Converted for the new archive on 14 July 2000. Some images and formatting may have been lost in the conversion.