It is 29 July as I write, and the summer is flying sunnily by. Despite the glorious weather, populations reported from across the country are low in most cases. Where high numbers are observed, these are usually of two migrants, the Red Admiral and Painted Lady. In short, hot, sunny weather is great for Ireland’s butterflies, but it’s just one ingredient needed for the meal. More resources are required to provide a happy home for butterflies. One explanation for low numbers is the scarcity of resources needed to grow and sustain populations. Populations reflect the carrying capacity of habitats as well as weather and predator populations. With 90% of EU-protected habitats in unfavourable condition, the reason for low abundance is clear.
Despite the ‘great thinning’ of the fabric of the natural world, our butterflies will still fly in August, despite diminished figures.
Here are the species we can hope and expect to encounter.
Green-veined White is a butterfly we expect to see. This gentle wetland butterfly can reach high numbers in August, and the rainfall in the first half of June will have helped its caterpillars. Look out for the lovely yellow form of the female.The Peacock is another expected butterfly. A nettle breeder, it flies in abundance in flower-rich rides in and near woods, where it overwinters. While its populations fluctuate from year to year, it has remained mainly stable since systematic recording began in 2008.The male Large White has no forewing spot on its upper sides, but it does have a forewing spot on the underside. Its upper sides are clear white with a forewing tip that is more extensive than in its smaller white relatives. Formerly much disliked for stripping brassicas when more commonly grown, this large, snowy butterfly is in far lower numbers than in the past.Small White female on a Creeping Thistle flower. This butterfly suffered a 78% decline from 2008-2024. You can expect to see it, but you should expect to see 12, whereas in 2008 you could expect to see one hundred.A beautiful male Brimstone feeding on Common Knapweed. Wills cigarettes featured the Brimstone on its cigarette cards in 1927, rather ironic in the context of the product promoted. The Brimstone vanished from Northern Ireland in the 1980s but has been stable in the rest of the areas it inhabits in Ireland since 2008. The butterfly can be expected in its habitats during August, the peak flight month for the overwintering adult butterfly.The Holly Blue is the greatest fan of our gardens. It loves gardens even more than wild habitats! A sunny, sheltered garden with shrubs is ideal for this gorgeous, lilac marvel. The spring females lay eggs on a range of garden shrubs, including dogwood and firethorn, but its big favourite is Holly. It lays happily on Alder Buckthorn, if you have this much rarer plant. Second-generation Holly Blues lay their eggs on flowering Ivy, so don’t cut it back until late winter. This is a butterfly we expect to see, and happily has not seen an abundance crash.The Common Blue (male pictured) remains widespread in wilder grassland in Ireland, using vetches and clovers as larval foodplants. Black Medic and Common Bird’s-foot-trefoil are commonly used where these grow in suitable conditions. The species flies in at least two generations annually, and responds to summer drought by producing very small individuals in late summer. In some years it flies into early October. This butterfly still belongs to the ‘expected’ category, but a decline of -68% between 2008 and 2024 threatens to relocate it to the ‘hope to see’ category.A lovely male Small Copper butterfly, second generation. This species had fallen by 68% in 2024 compared with the 2008 baseline. Its Irish distribution closely matches the Common Blue, but the Small Copper is naturally less numerous. This lovely butterfly hovers between the ‘expected’ and ‘hoped to see’ brackets.The Brown Hairstreak belongs firmly in the ‘hope-to-see’ basket. It is naturally rare, occurring in just 1.8% of Ireland’s 10km squares (18 out of 1019 10km squares). It depends on uncut Blackthorn, usually in scrub, adjoining unfertilised species-rich grassland in warm places. August is the key month for this autumn-leaf coloured butterfly.Grayling (female), Sheskinmore, County Donegal. Look for this large butterfly on tall dunes and on rocky outcrops, including outcrops in wet bogs. The Grayling’s peak month is August but usually flies from July to early September. It is disappearing from some apparently suitable places and is one of a group of brown butterflies that is declining in distribution and probably in abundance. It is a butterfly one hopes to see when exploring suitable habitat along the east coast, but one expects to see it in the right habitats along the western seaboard.The Wall Brown has declined in abundance and distribution. This once-common species is now rare or absent in most of Ireland. The species is endangered. August is the key month in its flight period.This Silver-washed Fritillary continues to fly in August, and one should expect to encounter it in clearings and rides in semi-natural deciduous and mixed woodland but not in dark plantation forests.The Small Tortoiseshell flies in numbers towards the latter part of August. It can appear anywhere, but it has fallen by -63% between 2008 and 2024.A Painted Lady basking in August 2025. We are having a glorious Painted Lady summer in 2026. It might reach high abundance this August. The Red Admiral is our other common migrant, and like the Painted Lady, it is thriving this year. August is a great month to see it.Clouded Yellow, Agios Georgios, Corfu. This beautiful migrant is making its presence felt in the southern coastal counties, and it might appear in numbers further north. Like Painted Lady and Red Admiral, it is having a bumper year.
