Species in the Spotlight: Marbled White

Sun 28th Jun, 2020

The marbled white is one of the most striking of all UK butterflies. Dan Lombard Senior Ecologist at Wold Ecology celebrates one of Yorkshire’s finest species. We hope you enjoy his blog and fantastic photos. 

Roosting male © Dan Lombard

Despite its appearance, this white-winged butterfly is more closely related to the ringlets and meadow browns with which it shares its grassland home than the true ‘whites’. The marbled white does however behave more like a white, being conspicuous on warm days with its distinctive strong, gliding flight, in contrast to the short, fluttering flight action of other browns. Unfortunately this spectacle is all too short, with the first individuals appearing around late June and the last seldom persisting beyond mid-August.

Roosting male © Dan Lombard

As one might expect from a butterfly which spends its life flitting between tall grasses in unimproved grasslands, the caterpillars are grass feeders. Having overwintered in a dormant stage, the newly-hatched caterpillars have their first feed in early spring, showing a preference for the narrow leaves of Red Fescue. Later they move on to coarser species like tor-grass, cocksfoot and timothy and switch to a more nocturnal lifestyle. Searching the flowering heads of the latter two grasses can also reveal roosting adults.

Marbled Whites gathering to roost © Dan Lombard

The marbled white has shown a marked increase in the region over the past two decades. Once restricted to isolated colonies on south-facing embankments, notably dry river valleys in the Wolds, it can now be found in a wide variety of well-drained calcareous habitats. I have even found small colonies in isolated urban areas within York City centre, notably road verges and unkempt grasslands. Undoubtedly, a warmer regional climate has increasing colony viability.

Male © Dan Lombard

The spring of 2020 has seen marbled whites and many other species emerge earlier than ever. Mathew Oates author of the excellent book His Imperial Majesty has found 10 species on the wing earlier this year than any since his records began in 1971.  

Dan Lombard Wold Ecology and Richard Baines