Butterfly transects are a well-established way of recording our wildlife. The Yarner Wood transect has been monitored since 1976 and is an important part of our Long-term Monitoring Network. We walk this transect weekly, for six months of the year, from April 1st to September 30th.
Which species and how many of each we see, varies widely. So far this year, in one week there was just one butterfly flying; another week 29 were counted, across five different species. The largest number of these were brimstones, with 23 recorded, these have been the most numerous. Others we have seen so far are: speckled wood, meadow brown, small heath, small white, orange tip, holly blue, peacock, red admiral and the rare pearl-bordered fritillary. Hopefully other species will turn up through the summer.
What affects the appearance of butterflies in and around the wood is difficult to say. The weather obviously has an effect, both the length and kind of winter we have had, humidity, temperature, food sources and perhaps the ongoing climate change factors.
The transect is divided into twelve sections and takes up to an hour and a half to complete. Brimstones appear in most of them, other species seem to prefer certain sections in particular; the open area of heath, the large field towards the end of the route, the damp area at the start of the Yarner drive, or in the wooded areas.
Five species winter as adults: brimstone, peacock, red admiral, comma and small tortoiseshell. I have seen one on a rare sunny winter day. My favourite butterflies are the bigger ones and those that stand still with their wings open for us to get a good look at, but they are all beautiful to see.
Walking around the woods is always productive of other creatures as well as the butterflies. A variety of small moths are usually in all sections. Luckily we don’t have to count them because they are really tiny! Also beetles, tiny spiders and literally thousands of wood ants swarming around their hills and often carrying an item bigger than themselves. Birds flit past, sometimes in and out of nest boxes, fixed for them, on various trees. Grey squirrels frequent one particular section, and occasionally we will see a deer. The best view I had of one recently, was when it raced down across the field in front of me!
The data we collect is inputted onto the United Kingdom Butterfly Monitoring Scheme by the end of October and you can view our records on the website (Records 1, Records 2). If you would like to read in more detail about the Long-term Monitoring Network at East Dartmoor NNR, please follow this link
Blog written by Janet Ritchie, Natural England volunteer
If you have been inspired to search for butterflies… through July to mid August, we are asking people to go in search of the elusive white-letter hairstreak. We are interested in any new records of these butterflies found in the NNR. They have been recorded high up in the elms trees found in the Bovey Valley Woodlands.
White-letter-Hairstreak Finder’s Guide.pdf