What do they look like?
Gatekeepers have orange upperwings with a broad brown edge. Males also have a prominent band of dark scales running diagonally across the forewings – the sex brand. This is a line of specialised scent scales called androconia forming a sex brand which is absent in females.  Both sexes have a large dark eyespot on each upper forewing and a much smaller one on each hindwing. The eyespots on the forewing contain two white dots and this can help with identification. With their wings closed a large eyespot and orange colour can be seen on the forewing but the hindwings have brown and cream shadings with a few tiny white spots.
 
The wingspan is between 37 and 43mm for males; 42 to 48mm for females.
 
Where are they found (in Britain and Ireland)
All southern and central England; most of Wales except mid-Wales; the north-west coast of England and south coastal Ireland. Not in Scotland.
 
What is their preferred habitat outside gardens?
The butterflies like to fly in places with long grass, shrubs and flowers.  Hedgerows, field edges, country lanes and gateways are usually ideal, hence the common names (it is sometimes called the hedge brown).
 
Resident or migrant?
Resident
 
When to see them?
The gatekeeper is another single brood butterfly of high summer seen from the end of June until early September.  They live in colonies with little movement between sites and the males can spend several days in one small area, frequently perching and keeping a lookout for females and rival males. Colony sizes vary depending on habitat and weather.
 
What happens in winter?
They overwinter as caterpillars. The butterflies lay their eggs from late July through August with the caterpillars hatching out during September. The caterpillars feed in the daytime until their first moult and then enter hibernation in October when they are still quite small. Feeding begins again in the spring, this time at night; the caterpillars grow slowly going through three more moults until they pupate in early June and so the cycle begins again.
 
 
Gatekeeper or Hedge brown Pyronia tithonus   
Family: Nymphalidae   Subfamily: Satyrinae
 
Female
Male
Underside - sexes similar
What do the early stages look like?
When the caterpillars first emerge from their eggs they are a very pale brown colour and about 1.5 mm long. Soon after beginning to feed they turn green with thin white lines running down their bodies. Apart from getting bigger their appearance is largely unchanged until the final (4th and 5th) instars when some of them turn brown. By the time of pupation, they are slug-shaped, 25mm long and eight to nine months old.
 
What do the caterpillars eat?
The caterpillars eat a range of grasses. The main ones recorded are cock's-foot Dactylis glomerata, bents Agrostis spp., fescues Festuca spp. and meadow-grasses Poa spp.
 
Flowers they take nectar from
The butterflies will feed on honeydew but also take nectar from many flowers. Brambles and ragworts are said to be favourites but common fleabane, cuckooflower, devil's-bit scabious, hemp-agrimony, red clover, thistles, water mint, wild privet, and wild thyme are also cited.  From my own experience a large patch of marjoram left to flower can attract lots of gatekeepers if you’re lucky enough to have a colony nearby.
 
How are they doing?
The population appears stable at present. The 2022 State of UK butterflies report shows a 42% decrease in numbers since 1976, but this is almost unchanged from the 2015 version.3.  
 
Other interesting facts
Historically, gatekeepers were not frequently seen in city-centre gardens. However, in recent years, they have been recorded at some urban sites across north-east London and Hampstead Heath and, more recently, on Wimbledon and Mitcham commons. It’s thought that this expansion into urban areas may be due in part to changes in the management of urban parks and cemeteries.4.
 
 
References
 
1. Biological Records Centre database 
 
2. UK Butterflies website   
 
3.  State of UK Butterflies report 
 
4. BTO website  
 
Page written by Judy Skinner, reviewed and compiled by Steve Head
Young caterpillar.
For other stages see UK butterflies page
Male
Female
Underside - sexes similar
Gatekeeper or Hedge brown  Pyronia tithonus   
Family: Nymphalidae    Subfamily: Satyrinae
 
What do they look like?
Gatekeepers have orange upperwings with a broad brown edge. Males also have a prominent band of dark scales running diagonally across the forewings – the sex brand. This is a line of specialised scent scales called androconia forming a sex brand which is absent in females.  Both sexes have a large dark eyespot on each upper forewing and a much smaller one on each hindwing. The eyespots on the forewing contain two white dots and this can help with identification. With their wings closed a large eyespot and orange colour can be seen on the forewing but the hindwings have brown and cream shadings with a few tiny white spots.
 
The wingspan is between 37 and 43mm for males; 42 to 48mm for females.
 
Where are they found (in Britain and Ireland)
All southern and central England; most of Wales except mid-Wales; the north-west coast of England and south coastal Ireland. Not in Scotland.
 
What is their preferred habitat outside gardens?
The butterflies like to fly in places with long grass, shrubs and flowers.  Hedgerows, field edges, country lanes and gateways are usually ideal, hence the common names (it is sometimes called the hedge brown).
 
Resident or migrant?
Resident
 
When to see them?
The gatekeeper is another single brood butterfly of high summer seen from the end of June until early September.  They live in colonies with little movement between sites and the males can spend several days in one small area, frequently perching and keeping a lookout for females and rival males. Colony sizes vary depending on habitat and weather.
 
What happens in winter?
They overwinter as caterpillars. The butterflies lay their eggs from late July through August with the caterpillars hatching out during September. The caterpillars feed in the daytime until their first moult and then enter hibernation in October when they are still quite small. Feeding begins again in the spring, this time at night; the caterpillars grow slowly going through three more moults until they pupate in early June and so the cycle begins again.
 
 
Young caterpillar.
For other stages see UK butterflies page
What do the early stages look like?
When the caterpillars first emerge from their eggs they are a very pale brown colour and about 1.5 mm long. Soon after beginning to feed they turn green with thin white lines running down their bodies. Apart from getting bigger their appearance is largely unchanged until the final (4th and 5th) instars when some of them turn brown. By the time of pupation, they are slug-shaped, 25mm long and eight to nine months old.
 
What do the caterpillars eat?
The caterpillars eat a range of grasses. The main ones recorded are cock's-foot Dactylis glomerata, bents Agrostis spp., fescues Festuca spp. and meadow-grasses Poa spp.
 
Flowers they take nectar from
The butterflies will feed on honeydew but also take nectar from many flowers. Brambles and ragworts are said to be favourites but common fleabane, cuckooflower, devil's-bit scabious, hemp-agrimony, red clover, thistles, water mint, wild privet, and wild thyme are also cited.  From my own experience a large patch of marjoram left to flower can attract lots of gatekeepers if you’re lucky enough to have a colony nearby.
 
How are they doing?
The population appears stable at present. The 2022 State of UK butterflies report shows a 42% decrease in numbers since 1976, but this is almost unchanged from the 2015 version.3.  
 
Other interesting facts
Historically, gatekeepers were not frequently seen in city-centre gardens. However, in recent years, they have been recorded at some urban sites across north-east London and Hampstead Heath and, more recently, on Wimbledon and Mitcham commons. It’s thought that this expansion into urban areas may be due in part to changes in the management of urban parks and cemeteries.4.
 
 
References
 
1. Biological Records Centre database 
 
2. UK Butterflies website   
 
3.  State of UK Butterflies report 
 
4. BTO website  
 
Page written by Judy Skinner, reviewed and compiled by Steve Head
       Garden Wildlife
             Garden Wildlife