There have been a number of unusual, and for local lepidopterists exciting, butterfly sightings in Butterfly Conservation’s Upper Thames Branch (BC UTB) region during the summer of 2014.
Most recently on 3rd September a transect walker at Little Whittenham, Oxon came across a female Brown Hairstreak testing new Blackthorn growth and possibly egg laying. This was some five kilometres south of BC UTB’s most southerly egg find prior to the 2014 season. Brown Hairstreak have also been recorded in their current flight season at some other less frequently reported locations: Headington in north-east Oxford, Gavray Drive Meadows in Bicester, Oxon; and BBOWT’s Leaches Farm nature reserve, Bucks.
There were two sightings of Swallowtail between 15th and 21st July at Flackwell Heath, Bucks and Caversfield, Oxon. A Scarce Swallowtail, a very rare migrant to Great Britain, was also reported from Chesham, Bucks on 18th July. These were all suspected to be releases, but the timing of three sightings over one week “leaves room to assume migration is a possibility,” to quote BC UTB. Migrant Swallowtails of the continental European form have been breeding in Sussex since last year (2013), which further suggests a possible northward expansion for the species. It’s worth keeping an eye open in 2015 then!
Lastly, on 26th and 27th July BC UTB’s first Camberwell Beauty since 2006 was photographed in neighbouring gardens in a Chilterns hamlet above Princes Risborough, Bucks. For news of all butterfly sightings in Oxfordshire, Buckinghamshire and Berkshire – and to report local sightings of your own – please visit the BC UTB sightings page.