Hallow Fields Butterflies – End of year report 2023

Starting at the beginning of April 2023 and running through to the end of September, Group members have been surveying butterflies at Hallow Fields each week and this is a summary of what we saw. Surveyors follow the same prescribed route at a slow amble, noting the numbers of each species they see. The results have been entered onto a spreadsheet and also entered into the UK Butterfly Monitoring Scheme (UKBMS) which is a nationwide record of butterflies seen by hundreds of surveyors all over the country. 

April 2023 was a cool wet month, not good for butterflies, and we had two weeks of zero returns but we did have one good week where 28 butterflies were recorded including 14 Orange Tips. May was a better month as it was a bit warmer with Orange Tips again being the most numerous species but also Peacock, Green-veined White and Brimstone were seen. Late May and early June are usually quiet, this being the natural gap between the end of the spring butterflies and the emergence of the summer species, and this is what we experienced. Toward the end of June began the emergence of the Meadow Brown, our most numerous species seen by a long way. Into July the Meadow Browns registered 170 at the peak. The other common summer butterfly, the Gatekeeper, emerges toward the end of July and into August and we had good counts of this species, up to a maximum of 18 in mid-August. Going into September, butterfly numbers fell as expected although temperatures held up well – we recorded mainly whites and Speckled Woods.

Overall we recorded 18 species and a grand total of 699 butterflies. The most common species being Meadow Brown (223), Large White (86), Gatekeeper (65) and Speckled Wood (49).

At the other end of the scale, it was sad that only two Small Tortoiseshells were seen – a once very common butterfly but alas not any more; also Common Blue (1) had a poor year. These low figures reflected the findings of other transect walkers all over the country.

The three common white species, Large White, Small White and Green-veined White, are notoriously difficult to identify in flight and I think all surveyors had problems with these! Altogether these three species totalled 168 seen.

Other transects nationwide reported a huge increase in Red Admiral numbers over previous years; we recorded 25 but obviously did not have anything to compare this figure with.

Mike Hails has kindly drawn up some graphs to illustrate numbers of each species present and numbers seen per transect.

Mike Hails has kindly drawn up some graphs to illustrate numbers of each species present and numbers seen per transect.

Another factor to take into account this year was that one field on the transect route (sections 3 and 4) had been sprayed with weedkiller, which is obviously not ideal for the survey as butterflies are attracted by flowering weeds. So the counts on these two sections were lower than expected. 

I am hoping that these figures will provide a base-line for the conservation work at Hallow Fields and that as improvements are made, butterfly numbers will reflect this and show increases in overall numbers and range of species. Currently the site mainly attracts only grassland species.

Call for butterfly surveyors 2024

I will soon need to set up a rota for these weekly surveys to take place in 2024 and am now asking for volunteers please to come forward to offer their help by taking on just a small number of transect walks over the 6 month period. Those who took part last year are very welcome to join again this year and new recruits will also be very much appreciated. 

The transect takes 1–11/2 hours; it is an easy, flat walk to be taken on a (preferably) warm, windless day and requires only fairly basic identification skills. I am happy to show you the route and explain what to do. If you feel unsure of your butterfly identifications, I will endeavour to pair you with a more experienced surveyor.

Please contact me if you are interested in taking part: email vanessa.chaplin@yahoo.co.uk or phone 07771 848700. Thank you.

Vanessa Chaplin