Butterflies are nature's artwork, symbolising both the beauty and fragility of the natural world. In Britain, we are fortunate that some of our most common species are also the most enchanting. My favourite is the red admiral, with its bright red sash across a velvet black background. Other common garden visitors like the peacock and painted lady are a glorious sight on a hot summer's day.

The smallest butterflies are the moth-like skippers with their rapid darting flight, followed by the blues, many with iridescent colours that reflect the sky. Other groups are white or yellow, like the brimstone, our harbinger of spring. Some of the larger species are fritillaries; the silver-washed fritillary is a sight to behold in high summer. Largest of all is the swallowtail, now confined to the Norfolk Broads where it swoops gracefully over the fens and occasionally visits gardens.

Unfortunately all is not well in the butterfly world: over half our species have experienced serious declines over the past 50 years. The main reason is the drastic loss of breeding habitats such as flower-rich grassland, reduced to small fragments in our modern, intensively farmed landscapes.

Butterflies have never needed support more than now. They are a true indicator of the health of the countryside and if we can understand their problems we can help much other wildlife. In conserving these vulnerable creatures we create a healthier world for us all.

Dr Martin Warren is chief executive of the charity Butterfly Conservation