Purple hairstreak

Purple Hairstreak butterfly

©Philip Precey

Purple hairstreak

Scientific name: Favonius quercus
The Purple hairstreak is an elusive butterfly with a brilliant purple sheen. It is entirely reliant on oak trees and can be spotted chasing around the treetops in woodlands and parks.

Species information


Wingspan: 3.1-4.0cm

Conservation status


When to see

June to September


The Purple hairstreak is a small butterfly that flies in the summer between the end of June and early September. It is very rarely seen as it spends most of its time perched on leaves at the top of oak trees. Very occasionally, it does come down to ground level, but it is best spotted with binoculars: males can sometimes be seen chasing each other in the treetops. Found in oak woodland and on solitary oak trees in parks or along hedgerows.

How to identify

The Purple hairstreak is an unmistakeable butterfly. Females are black above, with a purple patch on the forewings, while males are almost entirely purple above with a black border. The underside of both sexes is a silvery-grey, with an orange eyespot on the hindwing.


Fairly widespread in England, Wales and southern and central Scotland.

Did you know?

The Purple hairstreak is the only butterfly in the UK which is entirely reliant on the oak tree. It can use our two native species - Sessile oak and Pedunculate oak - as well as the introduced Turkey and Evergreen oaks.

How people can help

The Wildlife Trusts manage many woodland nature reserves sympathetically for the benefit of all kinds of butterflies, including the Purple hairstreak. A mix of coppicing, scrub-cutting, ride maintenance and non-intervention all help woodland wildlife to thrive. You can help too: volunteer for your local Wildlife Trust and you could be involved in everything from traditional forest crafts to surveying for butterflies.