WHAT will YOU be doing on July 24? The Dorset-based Butterfly Conservation charity hopes very much that you’ll be out in your garden or your local park, counting butterflies for them.

The first Big Butterfly Count starts on July 24 and lasts for a week. Butterfly Conservation’s director, Martin Warren says: “Just find a place where you might see butterflies, such as a garden or park, and count the different butterflies you see in just 15 minutes. You can make counts in several places during the week.”

And you’ll be in good company – among the counters will be Butterfly Conservation’s patron, Sir David Attenborough, who is understood to be counting butterflies in London. Butterfly Conservation staff will be counting the butterflies in and around their headquarters near Lulworth.

It’s important to count butterflies, says the charity, because butterflies and moths are very sensitive to environmental change, which makes them an excellent indicator of the health of the countryside. “Protecting butterflies means creating a healthier environment for everyone but conservation work must be targeted where the need is greatest,” says Martin Warren.

There are 58 species of butterfly native to Great Britain and more than 2,500 moth species. But don’t expect to see all of them; butterflies and moths are fussy about when they emerge and can only do so when a host of variables are in harmony, such as the weather, the warmth and whether their favourite feeding grounds – usually specific types of flower – are in bloom.

And don’t worry if you don’t know your Red Admiral from your hawkmoth – the charity has a handy guide you can print out from its website plus loads of tips on how to record your information.

Those who use bigbutterflycount.org to do this will receive 10 per cent off butterfly-friendly plants when they shop online at Butterfly conservation’s corporate supporter, M&S.