The butterfly recordings gathered by this website reached an all-time high of 89,204 last year, being 99% up on 2018! Our very grateful thanks to anyone who sent in a sighting.

This percentage increase is probably not indicative of quite such a good year as it seems: 2019 was the last year in a five-year recording cycle and we saw a huge effort to fill the ‘White Holes’ in the Dorset map (thank you again!). An analysis of all the website results, plus transect walk results and lots of other data sources is happening as this is typed, so we will know more detail before long.

It does seem, however, that some species did well. Our page which compares 2019 to 2018 will show you how each species fared, but to pick out one or two increases:

• Chalkhill Blues were up from 454 to 1239; this is a species which is causing us considerable concern at the moment, so the big question is going to be where these sightings came from: big swathes of Dorset seem to have lost their Chalkhills completely.
• The Silver-studded Blue was up from 1924 to 3286
• Orange Tip up from 443 to 826. These results both seem very low for a relatively common butterfly, so please do report your Orange Tip sightings later this year.
• Meadow Browns seem to take the gold medal, up from 9178 to 25391!

Meadow Brown female. Photo: Shona Refoy

Decreases included:

• Green-veined White down from 1161 to 561. This seems odd, so maybe it is under-recording rather than a real slump, but please do look out for this butterfly in 2020. It is not easy to identify from a distance, so have a look at our species page on it to help you.
• White Admiral down from 189 to 81. Dorset is not a heavily wooded county which is why this butterfly is not as numerous as in some other places, but this apparent decline is concerning and will need to be checked against other results.

White Admiral. Photo: Tim Field

The number of kilometre squares on the Dorset map that have been ‘filled’ with at least one butterfly result over the last five years looks good, and the website map is not the final one: there are 2019 results from transect walks and other places to be added yet. In 2020 we start with a blank map and try to fill it again by 2024.

Lyn Pullen sends her apologies to members for the 2018 Butterfly Report not yet having been published due to pressure of butterfly and other voluntary work – she will get it out before the 2019 one arrives!