Size and Wingspan
Distance and sex differences makes size difficult to judge in the field but over time it's possible to develop a sense of bigger than / smaller than between the species that can be useful. For comparative purposes, the smallest to largest average wingsize is listed below.
35mm - Small Heath
43mm - Gatekeeper
47mm - Ringlet
49mm - Wall Brown
51mm - Speckled Wood
52mm - Meadow Brown
56mm - Grayling
Non-visual Characteristics
Habitat and distribution can be invaluable aids to identifying which Brown butterfly you’ve seen, and this comes with practice and experience. Key factors to know are that Grayling and Marbled White are extremely restricted in range and limited to just a few sites in Norfolk at present, and the Wall brown and Small Heath are also less widely distributed than the other species.
Habitat
Small Heath - grassy heaths, lowland moors, coastal dunes
Gatekeeper - lane verges and hedgerows, scrubby heaths, open woodland rides, meadows and grassland
Ringlet - shady hedgerows, damp woodland rides, scrubby grassland
Meadow Brown - dry grassland, verges, woodland rides, scrubland, coastal dunes
Wall Brown - grazed downland, disused railways, field edges, coastal dunes
Speckled Wood - woodland glades and rides, lanes, wooded hederows, gardens
Grayling - coastal dunes, acid lowland heaths
Marbled White - chalkland flower meadows, woodland rides
Flight Times
Just anecdotally, from my own observations in the same locale, Gatekeepers have tended to emerge slightly later than their larger Meadow Brown cousins, but I am sure county level statistics are more trustworthy. In order of appearance, below is a list of Norfolk first sightings from the Butterfly Conservation Norfolk Branch Autumn 2024 Newsletter
Wall Brown - 3/3/23 -17/3/23
Speckled Wood - 25/3/23 - 18/10/23
Gatekeeper - 4/6/23 - 21/9/23
Meadow Brown - 7/6/23 - 16/9/23
Ringlet - 10/6/23 - 24/8/23
Small Heath - 26/6/23 - 25/9/23
Grayling - 26/6/23 - 18/9/23
Host Plants
Small Heath - various grasses including Annual Meadow Grass, Fescues and Bents
Gatekeeper - various grasses including Annual Meadow Grass, Cock's-foot, Common Bent, Common Couch, Fescues and Timothy
Ringlet - various grasses including Cock’s-foot, Creeping Bent, False Brome, Tor-grass, Tufted Hair-grass
Meadow Brown - various grasses including Annual Meadow Grass, Bents, Fescues and Rye grasses
Wall Brown - various grasses including Cock’s-foot, Black Bent, Common Bent, False Brome, Tor Grass, Wavy Hair-grass, Yorkshire fog
Speckled Wood - various grasses including Cock’s-foot, False Brome, Yorkshire fog
Grayling - various grasses including Sheep's Fescue, Red Fescue , Bristle Bent, Early Hairgrass, Tufted Hair-grass
Marbled White - Sheep’s Fescue, Red Fescue, Tor Grass
Resources
Butterfly Conservation Society - Species Information and Factsheets
R Lewington - Pocket Guide to the Butterflies of Great Britain and Ireland
A Riley - British and Irish Butterflies
All images taken by and © Kiri Stuart-Clarke. All rights reserved