Andrew Knights, one of the butterfly recorders at Magog Down, spotted a male Chalk Hill Blue butterfly (Polyommatus coridon) in Colin’s Paddock while carrying out a regular transect (survey) of the Down on Sunday 28 August.
A week later (4 September), Andrew came across a very worn female Chalk Hill Blue in the same area, feeding on a Creeping Thistle flower in the old shelter belt area next to North Down. Females are more sedentary than males (which can fly for over a kilometre) and this can limit colonisation, especially as chalk grassland areas tend to be fragmented and isolated. It is likely that these Chalk Hill Blues have come across from the Roman Road beyond Wandlebury.
There have been no previous sightings of Chalk Hill Blues at Magog Down. Work has been ongoing for many years to create an environment so that the Chalk Hill Blue could become established there. It has unique associations with its habitat. The Rangers, Claire and Nick Beale, have been working to increase the extent of Horseshoe Vetch which is the caterpillar food plant for the Chalk Hill Blue. The large group of local butterfly enthusiasts (who post regularly on the Magog Down Twitter account) are delighted at this outcome. If you are interested, go to our Twitter account @Magog Down to learn what has been seen recently.
Photos by Andrew Knights.