Look out for these golden and rich brown butterflies flitting around hedgerows and in tall ash trees in August and September. Brown Hairstreak Facts: • They are the largest of the five British hairstreak butterflies. • They are one of the last butterflies to appear each year and can sometimes still be seen flying in October. • They are an elusive species with adults spending most of their time in tree tops. • One of the first recorded specimens of any butterfly in Britain was a Brown Hairstreak female caught ‘near Croydon’ by James Petiver in 1702 – giving it the name of ‘Our Golden Hair-streak’ • Other early, alternative names included 'Double Brown Streak' and 'Golden Brown Double Streak'.