They are the butterflies of high summer and of long hot dusty days – the ones that small children run after on their holidays; the ones we set flying whenever we walk through a grassy field.
Today, in the 12th of our status reports, we look at six members of the family Satyridae or the browns, which are all visible now, as the schools are starting to break up, and will remain visible throughout the summer break.
As their family name suggests, all employ a colour scheme which involves variations on a theme in brown, apart from the stunningly different marbled white (and also the ringlet, which, when freshly emerged, can appear almost black).
They all lay their eggs on grasses such as fescues and bents and bromes, and they form part of that August experience of walking through grassland, when the grasshoppers bounce away from under your feet and the brown butterflies are flying all about you.
None required a special journey to see. We have encountered all these butterflies on trips to find other, rarer species which are extremely localised, for most of the ones profiled here are very widespread and common; indeed, the meadow brown is probably Britain's commonest butterfly, closely followed by the gatekeeper (in southern Britain). However in recent years the wall, also known as the wall brown, has declined alarmingly across many parts of Britain, while the small heath has also experienced the loss of many of its colonies.
Most of these butterflies share a typical feature of the brown family: a prominent eyespot in the upper corner of the forewing. This is an evolutionary adaptation against predators (mainly birds): it encourages birds to peck at the eyespot rather than at the more vulnerable body. You can often find these insects with a piece pecked out of the wing, but gamely fluttering on to live another day.
The Great British Butterfly Hunt: Species 34-39 (of 58)
The upper wings are a lovely velvety chocolate brown, and can appear almost black; when they fade the butterfly is quite similar to the male meadow brown.
Larval food plant: Coarse grasses including cock's foot and tufted hair-grass.
Where seen: Most of Britain apart from north-west England and northern Scotland.
Current conservation status: A big increase in populations of nearly 300 per cent since 1976.
The wall is well named for its habit of basking on warm wall surfaces. It is the brightest of the browns, and sometimes mistaken for a medium-sized fritillary, but the eyespot in the corner of the wing makes its identity clear.
Larval food plant: Various grasses from common bent to tor-grass.
Where seen: Over much of England, Wales and southern Scotland in dry areas.
Current conservation status: Down 79 per cent since 1976.
36. Meadow brown
If house sparrows were still as abundant as they were 30 years ago, we might say this was the house sparrow of the butterfly world: it is found right across Britain and in colonies of hundreds or even thousands.
Larval food plant: A wide range of grasses, from fescues to cock's foot.
Where seen: On grasslands and downlands, and also on roadside verges, hedgerows, waste ground, parks and gardens.
Current conservation status: Stable.
37. Small heath
Formerly another of our commonest grassland butterflies, the small heath has dwindled in numbers. You will struggle to see its orangey-brown upper wings for it always perches with its wings closed.
Larval food plant: A range of grasses including bents and fescues.
Where seen: Dry, well-drained places on downland, heathland, sand dunes and mountain sides.
Current conservation status: Down 59 per cent since 1976.
Quite like a smaller version of the meadow brown, but the gatekeeper has two white "pupils" in the forewing eyespots, while the meadow brown has one.
Larval food plant: Various grasses ranging from bents to common couch-grass.
Where seen: Pretty ubiquitous in the south.
Current conservation status: Stable.
39. Marbled white
Its striking wings with their black and white chequer give it the appearance of a miniature flying chessboard.
Larval food plant: Grasses especially red fescue, and also tor-grass.
Where seen: On unimproved grassland in various locations.
Current conservation status: Thriving.