It’s not often that butterflies make the news, but this year one species has turned up to the UK in their millions.
Painted Ladies (Vanessa cardui) are a migratory species that are seen every summer in the UK in numbers that vary annually. However approximately every decade they turn up in vast numbers. 2019 is certainly one of those years and the first since 2009 when approximately 11 million crossed the channel. Early counts suggest that this year the numbers may be even higher.
Painted Ladies are one of the most widely distributed species of butterfly; they are present on all continents except South America and Antarctica. They are the only species of butterfly seen in Iceland. They also perform the most spectacular migration of any butterfly, including the famous Monarch butterfly migration in North America. Their migration routes vary depending on where in the world they are of course but the ones that we see have originated from tropical Africa. They migrate North in overlapping generations, travelling over 12,000km annually. Individual animals can fly more than 4,000km including crossing the Sahara, as they follow suitable conditions for breeding. Populations that breed in some hotter areas of the Mediterranean in summer return south (again in overlapping generations) across the Sahara where the cycle starts again.
The butterflies that we see in the UK exploiting the wildflowers and sources of nectar in wildlife-friendly gardens tend to lay their eggs on thistles. Unfortunately Painted Ladies can’t survive our winters as eggs, caterpillars or adults so it is currently a one-way trip, though this may change in the future if our climate continues to warm.
For now, get out and enjoy them as it may be another 10 years before they can be encountered so frequently!
Have you seen an influx where you are?