If it isn't a leaf...

...it must be a Brimstone butterfly.

Unless I happen to see something really unusual, I promise this is the last butterfly of the year.  It's been a butterfly bonanza, but I suspect that yesterday was "peak butterfly".

The Brimstone was the first butterfly we saw in the Spring.  They hibernate for 7 months of the year in evergreen trees or hollies in the woodland, which sort of describes the edges of my garden.  They then find a suitable buckthorn bush in a wetland, which sounds like the scrub around the chalk pit lakes at the bottom of the hill, mate and lay eggs.  It takes 50 days to get from eggs, to caterpillars, to chrysalis, to new butterflies.  They've all just flown back up the hill to my garden because they like blue flowers - guess what, lavender and buddleia.

This is a young male, so perfect, and bright yellow green.  He was flirting with the young females which are paler, a sort of lemon yellow.  But they won't mate until next May.  They gorge themselves on nectar and then find a tree to hibernate in September.  They are among the longest lived butterflies - 10 to 12 months.  It's a strange thought that during the Winter months, there are lots of Brimstones asleep in the hollies waiting for the Spring.