The local results for the Big Butterfly Count are in and we are doing better than the national picture, but we could do better.

The annual Big Butterfly Count is a huge citizen science project run by Butterfly Conservation every year since 2010. Over three weeks in late July and early August, volunteers find a sunny spot and count how many of 20 different butterflies and day flying moths they see in a 15 minute period.

This year 80,000 volunteers carried out over 130,000 counts. The Sid Valley has an active citizen science population who carried out nearly 200 counts. The local picture is quite good, we see far more butterflies than some parts of the country, but this year’s local figures are down on last year, probably because of the awful spring weather. The long term trend is not so bright, people are seeing far fewer butterflies than in the past.

The top three butterflies in local counts were the Meadow Brown, Gatekeeper and Ringlet, the first two are also the top two nationally. We have more Ringlets than other places because we have many areas with the caterpillars’ food plant, rank grasses.

We are not so lucky when it comes to the Small Tortoiseshell. This colourful butterfly used to be very common but sightings have plummeted in recent years. Scientists are unsure whether there are far fewer, or it may be that their breeding cycle has changed with a changing climate and they are just not flying at the time of the Big Butterfly Count. Further work is ongoing to get a clearer picture.

The two big factors in butterfly populations are the weather and the availability of habitats, particularly food plants for the caterpillars. The count got off to a slow start this year because it rained most days of the first week, but the weather picked up and so did the butterfly numbers, but we were still 15% down on last year by the end.

Unsurprisingly, many more butterflies were seen out in the countryside than in gardens, even gardens which are planted to be wildlife friendly. The key factor is not the flowers but the food plants of the caterpillars and the connectivity between them.

Adult butterflies can travel around looking for flowers to provide the nectar they suck up through their long coiled probosces and, although they might have favourites, they can feed from a wide range of different flowers. Their caterpillars are often more fussy and so the adults tend to congregate where they can access their own food but also lay their eggs.

One example is the beautiful Six-spot Burnet Moth. You can see plenty of their red-spotted metallic blue wings at Jabob’s Ladder where there are plenty of thistles and ragwort flowers for the adults, but also a carpet of Bird’s-foot Trefoil which is the food plant of the caterpillars.

It is a similar story with the Ringlet and other meadow species and this explains the big difference in scores from grassland areas managed for wildlife such as Sid Meadow in The Byes and those mown regularly such as the Lawns area. The eleven counts from the long grass areas of The Byes yielded an average of 12 butterflies per 15 minute count. The seven counts in the Lawns area returned an average of only 4 butterflies per count.

There may be clover and daisies flowering among the short grass but meadow butterflies usually lay their eggs among tussocks of coarse grass so their caterpillars can feed safely deep in the shelter of the tussocks, so that is where the butterflies seek the nectar they need for themselves.

There is much more information about the local results on the Biodiversity Group website sidvalleybioversity.org.