Dear Readers, Butterfly Conservation have just published their report based on the Big Butterfly Count this year, and it makes for very interesting reading. First up, the Jersey Tiger, the Vulcan Bomber of the moth world, is up by an amazing 136%, making it the species with the biggest single increase. Anecdotally, people have been tripping over these moths all over London, and at one point there were three in my garden alone. The caterpillars feed on hemp agrimony, of which I have several unruly clumps, so this might be part of the explanation.
In other news, blue butterflies have had an excellent year, with Holly Blues up 120% from 2021, and Common Blues up 154%, although the blues had a very bad year in 2021 so it isn’t quite as impressive as it seems.
Gatekeepers had a very good year too, with nearly 143,000 spotted, making them the commonest butterflies in the count. They were up 57% on 2021.
However, while we celebrate these winners, it’s worth noting that overall, numbers are down – each person who counted for the survey only saw an average of 9 butterflies, an all time low for the 13 years that the survey has been running. There was a hope that the numbers would be up because of the hot summer, but clearly habitat destruction has a bigger impact. Some species, such as the Jersey Tiger and the blue butterflies are heading north, as climate change makes the temperature conditions more amenable, but some very common, iconic butterflies are still declining.
The Red Admiral was down 20% on the 2021 figures.
The ringlet is down 38%
And the Marbled White is down 71%. This, however, is a butterfly that has been making a comeback in London in particular, and which likes unimproved grassland. It lives very briefly as an adult (less than six weeks), and I wonder if the timing of the count didn’t quite coincide with its emergence this year. Fingers crossed. You can read more about this species, and some other London butterflies, here.
So, there are ups and downs but it is something of a depressing picture. When we’re planning our gardens (if we’re lucky enough to have one), or campaigning for local green space, it’s so important to make sure that there’s something for caterpillars as well as adult butterflies, even if that makes the place a little untidier than we’d like. Let’s see if No Mow May has had an impact when the count takes place next year – I get the feeling that it was taken up as a challenge by more people than usual, which will have saved a lot of eggs and caterpillars. Long may it continue.
You can see the full results at the link below, including a breakdown by country which made for very interesting reading.