According to the National Trust, last year’s changeable weather has resulted in an influx of migrant species with mixed fortunes for resident British wildlife.
The ‘stop-start’ spring, with temperatures warming then plummeting in February and March, before warming again, brought migrant species such as butterflies to our shores. But the changeable summer, with short, sharp rainstorms, proved to be challenging for some wildlife, including water voles, puffins and terns. The end of the year was warm and wet, with few cold spells, but more deluges of rain particularly in November resulted in flooding in many parts of the country.
Warm spells of weather in the early half of the year saw migrant species of butterflies, moths and dragonflies from the south and east arrive in the UK. Significant numbers of painted lady (Vanessa cardui) butterflies were seen arriving en masse for the first time in a decade.This 5-7cm orange and black spotted butterfly is commonly seen in the UK but the last mass arrival was in 2008. This year’s influx, with over 420,000 recorded, appeared to be countrywide particularly in the North East, Lake District, Northern Ireland and South West.
In August, an exotic migrant from the Mediterranean, the long tailed blue butterfly (Lampides boeticus) set new records with 50 seen across the south coast of England, mating and laying eggs. It was the third time in the last six years that numbers of this delicate butterfly appear to be increasing, although successive generations haven’t yet made it through a British winter.
A rare moth was also recorded at Killerton in Devon – the Clifden nonpareil (Catocala fraxini). As the largest underwing moth to be found in the UK with a uniquely blue ‘underwing’, it became extinct as a resident in the UK in the 1960s, but over the last few years it has been trying to re-establish itself. Many more have been spotted in the south of the country, with numbers at their highest for at least 25 years.
June, July and October also saw high numbers of migrant dragonflies including the red-veined darter and vagrant emperor. Rare, vagrant birds were also seen in the summer. A Brown Booby, usually at home in the Caribbean, or around Venezuela, was spotted for the first time in Kent and two were seen in different parts of Cornwall for the first time ever in August.
And, last autumn, birds including the American black tern at Longham Lakes, Dorset and a red eyed vireo, a small songbird, on the Lizard were seen, probably due to low pressure systems driving them off-course on their journey down the eastern seaboard of the USA.
Ben McCarthy, head of nature conservation and restoration ecology, said, “Sightings of migrant insects and birds are becoming more common. This is a result of our changing climate. Although this can seem exciting, the obvious flipside is how these changes will start to affect some of our native species already under pressure from intensive land use, habitat fragmentation and climate change.
“By improving the condition of our remaining habitats and increasing patch size it is easier for species to move across landscapes in response to our changing environments. It also means that when they arrive in their new location there is habitat to support them. If our wildlife doesn’t have anywhere to move to as temperatures rise and the weather changes, over the coming years we will inevitably see more and more species at risk of becoming extinct.”
Keith Jones, climate change expert at the National Trust, added, “This year’s changeable weather is a symptom of the warming climate. The more our temperatures go up – the more erratic our weather will become. This will force changes to the lifecycles of many species as food webs are knocked out of sync. Like all conservation organisations, we are working hard to protect and care for habitats, and everyone has a part to play in the battle against climate change.”