It’s not just the engineering and beauty of these intricate creations that draw attention, the counting of butterfly and moth webs on peatland restoration sites is a crucial technique for keeping an eye on their population size. Monitoring the number of webs can tell us how much a species is thriving or declining on a particular habitat. 

On Islay, Butterfly Conservation are going to continue the monitoring of four sites we monitored during the Collaborative Action for the Natura Network (CANN) project where we worked on restoring precious peatlands on the island for five years. Butterfly Conservation secured funding to take over the monitoring of the threatened marsh fritillary on these sites (and potentially more) for the next 10 years. 

“We are thrilled that the legacy of the CANN project lives on and will provide really valuable insight on this rare and declining butterfly,” says Angharad Ward, who works on ACT’s peatland initiative. 

Marsh fritillary butterfly on Islay, by Angharad Ward

Once widespread in Britain, the marsh fritillary is a threatened species which is now found mainly on the western side of Britain. And its future is uncertain. 

Last week, Anthony McCluskey of Butterfly Conservation held a volunteer training event to teach volunteers how to identify marsh fritillary larval webs, which are spun by the caterpillars of this beautiful butterfly. Angharad Ward joined Anthony for the morning training session. In the afternoon, the pair visited one of the best sites on Islay for the marsh fritillary to count this years’ webs – the site visited is one that was monitored during our CANN project, which concluded last year.

Marsh fritillary spotting tips

  • Butterflies can best be seen in June
  • Webs are best seen in August and September
  • Caterpillars spin these webs for protection and there can be over 100 caterpillars in just one web! 
  • Look out for the purple Devils-bit scabious flower, which is the foodplant for the caterpillars. Their webs will be nearby.

Read all about the marsh fritillary here 

Volunteer pointing out a marsh fritillary web , by Angharad Ward

Community-led peatland restoration

In 2022, we launched our new peatland initiative to build upon the work started within the CANN project. Our aim is to make peatland restoration more accessible to everyone on the islands of Islay, Jura and Colonsay, regardless of the size of their landholding. At the same time, we're also building the connection that people have with the peatlands around them and we're improving our understanding of the species that call this landscape home.

Read about our peatland restoration work here 

Marsh fritillary web with caterpillars basking in the sun, by Angharad Ward