The cold 2021 spring and early summer seems to have had an impact on some of our garden butterflies – so far in 2021 nearly all of the 13 species, monitored as part of the British Trust for Ornithology’s (BTO) Garden BirdWatch (GBW), are being seen in fewer gardens and are also appearing later than usual.
The cold start to the season is probably behind the lower than average reporting rates for Comma and Green-veined White but it is still early in the season and with good weather their numbers could pick up. An increasingly common butterfly, the Holly Blue, is normally seen most often in May, but as a result of the cold spring weather this year they have peaked in June. As part of National Butterfly week, the BTO are asking people to look out for butterflies in their gardens and take part in its Garden BirdWatch, which also monitors butterflies and other garden wildlife alongside birds. It is free to take part in and is the only survey that monitors garden wildlife throughout the year.
Rob Jaques, BTO Garden BirdWatch, said, “It is not all bad news for our garden butterflies, at least one has done better than usual this year. Painted Lady, a migrant species which travels from as far as the Mediterranean and North Africa, has been seen in twice as many gardens in June than a typical year. By submitting observations into the BTO GBW we will be able to monitor how they do as the summer progresses, and monitor those species, such as Meadow Brown and Ringlet that are just beginning to emerge.”
The BTO GBW has been monitoring garden butterflies since the survey began in 1995 and it is thanks to those people who take part in the survey that we are able to keep an eye on how they are doing year on year. The BTO would love more people to tell them about the butterflies they see in their gardens. To take part and for more information, please visit www.bto.org/gbw
Header image: Ringlet. Credit: Liz Cutting.