In the winter of 2012/13 Nicholas planted a few Alder Buckthorn saplings, which are the food source for the Brimstone caterpillar. Quite simply if there was no Alder Buckthorn, or Purging (Common) Buckthorn, the Brimstone would not exist. Luckily we now have regular visitors.

Can you spot the Brimstone Caterpillars in this picture? They are very well-camouflaged....