Williamson's Weekly Nature Notes

It shows what all song thrushes do in hot weather '“ break open snails to eat the innards.

They leave these piles of empty shells on the paths, known as thrush anvils. It's a bit like litter louts throwing out their rubbish after a picnic.

I'm very grateful to Roger. Back in 1964, he started me on recording positions of breeding birds for the CBC '“ Common Bird Census.

This was one of the first methods of finding out what was happening to birds in this country. Were they increasing or decreasing? The British Trust for Ornithology started the scheme under a namesake of mine, Kenneth Williamson. He was no relation.

Anyway, Roger lived in Sussex and came over to Kingley Vale to set me on the business of listening to birds singing in the breeding season and marking their position on to maps.

I have carried out my CBC every year since 1964 and that meeting with Roger, and it must be the longest-running in the UK.

For full feature see West Sussex Gazette June 4