Hertfordshire & Middlesex Branch

Distribution and Status

The Small Heath was fairly widespread in the two counties in th 1980s and 1990s but by the start of this century many colonies had been lost. Many grassland places like meadows had been left unmanaged giving rise to taller vegetation unsuited to this species. 2017 saw a welcome return for this butterfly and abundance increased further in 2018 with colonies once again found in south Hertfordshire and Middlesex. In 2022, however, numbers have dropped about 40% since the 2015-19 period although there has been a similar increase in range

Habitat Requirements

Grassland where the sward is kept short and is most common on well-drained soils like chalk downland, heaths and coastal dunes. Smaller colonies can occur in woodland rides, roadside verges, disused quarries, waste ground and even large gardens

Larval Foodplants

Sheep's Fescue Festuca ovina is probably most frequently used. Creeping Bent Agrostis stolonifera, Smooth Meadow-grass Poa pratensis

Adult Food Sources

Meadow Buttercup Ranunculus acris, Devil's-bit Scabious Succisa pratnsis, Common Bird's-foot Trefoil Lotus corniculatus

Behaviour/Observation notes

Males are very active when patrolling over open grassland around a suitable landmark, like a shrub, in search for females. Mated females will stay in the vicinity of the foodplants and can be approached with ease. The butterfly always basks with its wings closed

Life History

Two or three generations are produced each year but they often overlap so the butterfly can be seen anytime between May and September. Eggs are laid singly on a grass blade. Larvae spend much of their time at the bottom of a tuft of grass but will feed at night on the grass tips. Larvae will either hibernate or develop to form pupae suspended on a grass stem