Our guest blog this week is written by our Isle of May national nature reserve manager, David Steel, who saw an influx of a favourite visitor to the island this week.

Painted Lady butterfly

Over the last five days, the Isle of May has experienced an invasion only rarely seen before. At the weekend, the island welcomed thousands of Painted Lady butterflies with an estimate of 10,000 individuals present on Sunday, with several thousand a day since then. Staggering numbers for an insect, let alone a butterfly! 

A Painted Lady butterfly taking advantage of the flowering ragwort.

This invasion was not just confined to the Isle of May, as the entire east coast of the United Kingdom were reporting vast numbers and it’s just so impressive to witness. But why were we getting so many and where were they coming from?

1, 2, 3…it’s easy to lose count!

Every year, huge numbers leave tropical Africa and head north reaching as far north as the Arctic Circle (over 7,000 miles…for an insect!) However once every decade or so, numbers are great (the last big invasion occurred in 2009) as a result of good breeding conditions on their migration route — hence the bigger than normal numbers. The natural world can be mind-blowing at times and this is just another fine example. So the next time you see one, just appreciate how far those little wings have travelled!