The Emperor Strikes Back

Once thought extinct in many areas, purple emperors are now turning up everywhere, even in supermarkets.

- Matthew Oates

Though most of our UK butterflies have suffered horrific declines in recent decades, a brave few are bucking the trend. None more so than the purple emperor, Apatura iris, long regarded as a rare denizen of southern oak woods – even though its essential requirement is the humble sallow bush, the caterpillar’s foodplant.

The State of the UK’s Butterflies 2015, a review produced by Butterfly Conservation and the Centre for Ecology and Hydrology, shows that during the 10 years leading up to 2014, the purple emperor increased its distribution by a staggering 135 per cent. Its closest rival was the silver-washed fritillary, another showy butterfly, which expanded its range by 55 per cent during that time. The next review, likely to be published late next year, should show the continuation of that positive trend.

In recent years, individuals of this distinctive butterfly have turned up in an impressive range of unlikely situations, which is not surprising, as it has eccentric tendencies and pushes limits – all limits. Purple emperors have been seen in several supermarkets (mainly Tesco, but also Sainsbury’s and Waitrose), two nursing homes, two public schools, a hospital, a borstal, a prison, a trout farm, an ammunition dump, a crematorium, the national film archive at Berkhampsted, outside the Royal Courts of Justice in central London, and, best of all, the departures lounge at Gatwick Airport. Most of these were dispersing males.