Although white in colour, this species belongs to a group of butterflies known as the ‘browns’. Historically it was found in a few different localities across Cambridgeshire, but it seems to have been very localised. Numbers fell during the mid-1900s, as its long grassy habitats and road verges came under threat from agricultural intensification and changes in management. However, more recently the marbled white has made a resurgence in the area, increasing in distribution and abundance, reaching similar numbers or surpassing those seen in Jenyns’ day. Climate change is again likely to be a factor, as the species can now use rather uninspiring areas of grassland whereas formerly it occupied only warm, dry and flower-rich chalk grasslands. For example, the natural regeneration of grassland where former arable fields have been allowed to rewild as part of woodland expansion projects at Gamlingay and Waresely woods have become hotspots for this butterfly.