Butterflies, moths and other invertebrates
Butterflies on Magog Down
Over the last thirty years, since the Down was created from former farmland, butterfly species have become established by natural means (that is, resident species which are common in the Cambridge area have spread into it). Regular surveys of the butterfly population are undertaken using the formal ‘Transect Method’ of monitoring. Through the summer months the same areas of Magog Down are walked regularly, counting the butterflies that fall within a 5m square around the surveyor.
The countryside of Magog Down provides a mosaic of butterfly habitats. By clicking on the images below, you can find information on the range of butterflies that are seen throughout the year.
Brimstone (Gonepteryx rhamni)
Common Blue (Polyommatus icarus)
Marbled White (Melanargia galathea)
Meadow Brown (Maniola jurtina)
Orange-tip (Anthocharis cardamines)
Painted Lady (Vanessa cardui)
Peacock (Aglais io)
Small Blue (Cupido minimus)
Small Skipper (Thymelicus sylvestris)
Small Tortoiseshell (Aglais urticae)
Hedgerows and woodland shrub margins provide a profusion of plants, shrubs and trees where many species of butterfly feed and breed, also offering shelter from wind, sun traps for basking and shade for species that prefer partial sunlight. Hedgerows also link habitat areas, providing butterflies with protection and nectar when they are moving across open areas. Some butterflies hibernate in hedges, while some individual male butterflies establish ‘territories’ along sections of hedgerow.
The chalk grassland of Magog Down has a very rich flora with wild flowers, herbs and grasses adapted to the dry conditions. Management of chalk grassland is essential to ensure that these plants can flourish, so that they can flower and provide nectar, develop seeds and produce seedlings. Meadows are grazed or cut on rotation, with long grass areas providing summer and overwinter shelter and food for many birds, insects and mammals. The meadows are home to large numbers of scarce and highly local butterflies and moths whose caterpillars feed on specific plants.
Colin’s Bank on Magog Down
Professor Colin Smith was a keen lepidopterist who took a great interest in the Down. He was convinced that the increase in the natural flora would provide the necessary food supply to encourage a further growth in the number of Butterfly and Moth species on the Down.
He regularly contributed articles to the Trust’s Newsletter and carried out surveys over several years, and by the end of 1995 had recorded 20 species of Butterflies and 152 of Moths.
His death in 1997 is marked by a seat on the North Down, but two years later this site was identified by Dr Max Walters and Gerry Haggett, a Norfolk Naturalist, as one which if cleared of trees and shrubs, would produce an ideal sunny, sheltered bank on which to improve the variety of native chalkland flora. The initial work was carried out in 2000 with financial support from Colin’s family.
Further work to improve the diversity of the natural flora providing an increased food supply for Butterflies, Moths and other insects took place in 2004 and was part funded by an Environmental Grant from Cambridge City Council.
The most recent project has been to open up the area behind the bank, where the topsoil has been removed down to the chalk to encourage chalk grassland species to re-establish and flourish.