Much of the biodiversity monitoring that takes place at Hope Farm is focused on birds, as you would expect. Fifteen years of breeding and wintering bird surveys has shown just how well birds have recovered during RSPB ownership and management of this farm. But as we all know birds are just one part of the ecosystem here.
We also monitor butterflies and bumblebees regularly during the spring and summer, and moths every night of the year. It really is a delight walking alongside our pollen and nectar margins, or flower rich meadows, and seeing the abundance and diversity of butterflies, bees and other insects.
While most of the species are expected, every now and again nature springs a surprise on us, and we get quite excited!
Remarkably we have had two such moments this summer.
The first happened while two of our Senior Conservation Scientists, Tony Morris and Rob Field, were inspecting a pollen and nectar research margin. When they came back to the farmhouse they were very quick to tell us about a white-letter hairstreak they had seen and photographed. To our knowledge this was only the second record of white-letter hairstreak on this farm, with the first being recorded during in 2010 during a farm walk to celebrate the farms 10th anniversary. Amazingly the next day when Derek Gruar, the Senior Research Assistant at the farm, and I went to check the margin we discovered at least 3 hairstreaks, and possibly four!
White–letter hairstreaks are a species associated with elm trees, and the records here this year were of adults feeding on a vetch dominated margin alongside elms trees.
White-letter hairstreak feeding on vetch at RSPB Hope Farm copyright: Ian Dillon/RSPB
The second Lepidoptera moment occurred when I received an email from our volunteer moth identifier, David Kipling. He had identified a toadflax brocade which was a new species for the farm. This a species which was first recorded in south-east England in 1950 and has slowly colonised and expanded north since. There appear to be several small colonies in Cambridgeshire, but it is still exciting to learn of a nationally scarce moth being found on the farm.
Also seen recently was a marbled white butterfly which appears to be another butterfly that is slowly expanding its range and colonising new areas. We have had several sightings in recent years so it would be equally exciting if these whites did settle to form a new colony at Hope Farm.
Being early July, the peak of butterfly and moth activity may lie ahead, so you never know we may have yet more exciting Lepidoptera to report to you by the end of the summer.
If you would like more information on Hope Farm please contact:
Ian Dillon (Hope Farm Manager): ian.dillon@rspb.org.uk