Butterflies are seen throughout the year in Dorset, admittedly only in small numbers, during the winter months, but there were unusually few reports of any sightings in January this year. The first was on the 20th, of a Red Admiral. That was followed by two reports of a Brimstone on the 22nd. Thus, there were only three butterflies of two species recorded during the whole month. Of course, there may have been other records submitted elsewhere that we are not aware of yet, but the website is now one of the main locations for records to be sent to and it probably gives a representative indication of the overall picture.
The unfavourable weather during the month must have been a factor in such a small number of butterflies being seen, with only a few mild or sunny intervals between cloudy, cold and wet periods, but it does not seem to have been appreciably worse than the January weather in recent years. It is interesting therefore to make some comparisons in the number and emergence datesof butterflies over the past three years.
In 2020, 13 butterflies of five species were reported. The first was a Red Admiral seen on the 2nd, followed by Peacock, Brimstone, Comma and Small Tortoiseshell.
In 2019, 12 butterflies of four species were reported. Red Admiral and Peacock both appeared on the 1st and after that Small Tortoiseshell and Painted Lady were seen. The latter was clearly a bit of fluke. No less than seven of the 12 individual butterflies were actually seen on the 1st of the month., this must surely be something of a record for the start of the year.
This year the first butterfly sighting was some three weeks later than in the past two years so I thought it would be interesting to find out how long an interval there had been since the last sighting in 2020. Robin George kindly searched in the database for me and it turned out to be a gap of 36 days. We have to go back to the winters of 2003/4 and 2004/5 to find longer periods. In the first of those winters it was 45 days and in the second 46 days. Oddly enough, in both 2004 and 2005 the first butterfly was seen on the 12th January. This indicated that butterflies had disappeared relatively early in 2003 and 2004.
One other interesting fact that Robin discovered was that there are records of sightings of Red Admirals on every day of the year except for December 15th. Perhaps we should organise a Red Admiral Hunt on that date next winter to try to fill the gap!
Our thanks to Adrian Neil for this article.