A rare migrant butterfly from Europe appears to be attempting to establish a colony in Britain. The Queen of Spain Fritillary butterfly has been breeding at a location on the Sussex coast. The butterfly has been increasing in numbers across northern Europe and its arrival in Britain is almost certainly a sign of climate change.
The butterfly, although common in northern France, was hardly ever seen in mainland Britain between the 1950s and 1989. Since then sightings have become more frequent and there was a short-lived breeding colony in Suffolk in the late 1990s.
However, Queen of Spain Fritillary butterflies have been seen along the Sussex coast in the past month and Neil Hulme of the Sussex Branch of the charity Butterfly Conservation has photographed them mating.
These appear to be the progeny of an immigrant female butterfly spotted nearby in July. He and other Sussex butterfly enthusiasts are now waiting to see if this results in a permanent Queen of Spain colony. In particular they are searching for the butterfly's eggs, which are usually laid on field pansies growing on the edges of arable fields.
Experts think that the warm, sunny autumn will have helped them reproduce again. Dr Tom Brereton, Head of Monitoring at Butterfly Conservation's national HQ, said that the Queen of Spain Fritillary had been edging northwards over recent years, especially in warm summers.
He said: "It is most likely that the Queen of Spain Fritillaries which arrived in July were migrants dispersing from strongholds in eastern Normandy, northern France. From the Normandy coast near Le Havre to Sussex, the sea crossing is a distance of about 90 miles - i.e. a six hour flight in favourable southerly winds."
Neil Hulme, chair of Butterfly Conservation's Sussex Branch, said: "I was amazed to see this incredibly rare butterfly in Sussex but even more amazed to see a mating pair late in October. It does look like they are trying to establish a breeding colony for the first time in Sussex".
If the Queen of Spain does establish itself in Britain it will be the third butterfly to do so in the last 20 years, following the Red Admiral which now overwinters regularly across southern Britain and the Clouded Yellow which breeds regularly at one location on the south coast.
The Queen of Spain name was given to the butterfly in 1775 by Moses Harris in The Aurelian's Pocket Companion, but there is no explanation for why he did so.