Strumpshaw Fen: Swallowtail butterfly thrills enthusiasts

Butterfly enthusiasts have descended upon an RSPB nature reserve to catch a glimpse of one of the UK's rarest and largest butterflies.

Swallowtails can only be found in the Norfolk Broads.

Site manager Tim Strudwick said people come from around the UK to see the "separate subspecies of swallowtail".

The insect with its pale yellow wings, black veins and blue margins is a wetland specialist and has a wing span range of between 80 to 90mm (3in to 3.5in).

Pictures by Shaun Whitmore