Insh Marshes RSPB Reserve - Dark Bordered Beauty Bash

Saturday 3rd August 2019

By Pete Moore

Twenty-two folk turned up for the Big DBB Bash at RSPB Insh Marshes. Eighteen moth traps had been set up the day before and run overnight in areas where the habitat looked good for Dark Bordered Beauty i.e. areas of low growing aspen suckers – the food-plant of this rare moth, found only on three sites in Scotland and one site in England.

 

After a run of exceptionally warm nights (and bumper hauls of moths) it turned cool and clear on the night of the trapping. Sod’s Law. Sure enough, there were low numbers of moths in the traps. This would normally be very disappointing but……it turned out that we saw a record number of DBB! RSPB volunteers Thijs and Poppy found 15 DBB when they covered up the traps in the morning. Then during the course of the day, a further 14 were seen, either inside traps or disturbed from the vegetation, giving a grand total of 29 DBB, all of them males (the males are much more active than the females and thus more likely to be seen flying or caught in light traps). 22 of them were potted up (7 escaped capture) and given to Tom Prescott to have their wings marked with unique combinations of coloured dots. This was part of an MRR project – Mark, Release and Recapture – being undertaken by Tay Davies through a Graduate Placement with Scottish Natural Heritage. Through the recapture of marked individuals we can learn how far the moths fly. This is important information for us to understand how readily the moths can occupy new suitable habitat.  Also, by comparing the number of marked individuals with unmarked individuals, an estimate of the population size can be made. All of the marked moths were released unharmed at their point of capture.

 

So, it was a very successful day with lots of DBB being caught and marked. Plenty of other species were also seen, even though overall numbers were low. With eighteen traps to go through, it was maybe just as well that we didn’t have a bumper haul of moths – it would have taken us days to go through them!

 

Many thanks to Thijs and Poppy for helping to set up the eighteen traps, fire them all up on Friday evening and then get up early Saturday morning to cover them up and pot up DBBs. Thanks also to the moth “experts” who went through the traps and identified moths – Tom Prescott, Mike Taylor, Thijs Claus and Bill, a moth-er from England.

DBB Paparazzi

 

 

 

Marked Dark Bordered Beauty