This marker on the Cambridge Butterfly Trail is at Byron’s Pool local nature reserve – see the map above.

This is a small, elusive butterfly that spends most of its life high in the canopy of oak trees, making it tricky to spot.

While it often looks dark at a distance, males have a striking purple sheen on their upper wings that glints in the sunlight. It’s one of the few butterflies in the UK that feeds primarily on honeydew rather than nectar, which it collects from aphids in the treetops.

Although widespread across southern Britain, it is easily overlooked because of its secretive habits. The best chance to see one is during warm summer evenings, when they sometimes come lower down to bask or feed.

For more information, please visit Butterfly Conservation’s page on this species – Purple hairstreak.