Butterfly surveying in the South Downs National Park

Written by Charlotte Wray, Assistant Ranger

What better way to spend a hot July day than walking through beautiful chalk grassland surveying butterflies?! This is how South Downs Volunteer Ranger Service member John Walton and I spent last Thursday.

In the Western end of the South Downs we carry out three butterfly surveys throughout the summer across three chalk grassland sites near Winchester, as part of the monitoring programme that feeds into the Winchester Downs Cluster Group. Last weeks’ site was Hockley Golf Club, where we have been managing scrub and encouraging grazing since 2012. Our volunteers have spent a great deal of time working on all three sites and it is encouraging for them to see the results of our surveys, which we also share with Butterfly Conservation.

A particularly exciting find, in addition to the 19 other species spotted this year so far, was a brown argus near the 13th hole. This butterfly, although brown, is actually a member of the blue family and is quite fussy with its choice of food plant preferring rock rose and some wild geraniums. Its presence is an indication that the grassland management we are carrying out is having the desired effect and is producing a good habitat for this and other chalk grassland dependent species.

If you’re interested in carrying out your own survey then you still have time to join the Butterfly Conservation’s Great Butterfly Count which continues until the 06 August. With three-quarters of British butterfly species in decline, surveys such as these are incredibly important in helping to monitor the status of these important indicators of biodiversity.

Photo Brown Argus © John Walton