This pattern of British butterfly decline was and is an advance warning of what can happen in the United States and elsewhere. It is a warning to ecologists, land use planners, landscape architects and the more broadly-concerned population of gardeners - anyone who lines up on the side of concern for and understanding of the need for native plant diversity - that something should be done to help butterflies.
Nature lovers that they are and lacking great diversity when it comes to wildlife, many British are concerned about whatever wildlife is left. Perhaps because they lack mammal diversity, their birds and butterflies take on more importance. Avid butterfly watchers, according to what I read, have determined that at least 50 species have seen declines, sometimes drastic, in many places.
The story of decline is the same in Britain as in the United States - loss of habitat. Experts speculate that the loss of boggy and wet areas - the British call them fens - was responsible for disappearance of the Large Copper. The Mazarine Blue and Large Blue succumbed because of changes in agricultural practices, which replaced natural grasslands with crops.
Following a decline in sheep husbandry, which used to keep grasslands closely cropped, rabbits continued close cropping until large numbers of them succumbed to disease in the 1950s. Grasslands quickly became overgrown and less desirable grasses and shrubs choked out choice butterfly plants.
Elsewhere, in Southern England, heath lands reclaimed for agriculture since the early 1800s affected the Grayling and Silverstudded Blue. Wetland drainage has had an adverse impact on the Marsh Fritillary whose colonies have declined anywhere from 60 to 80 percent. In Northern England, the Large Heath was reported in decline because mosses are being lost with land drainage.
Another habitat concern to British butterfly lovers is the loss of thousands of miles of hedgerows. My rough interpretation of a hedgerow is a very old roadside wall of hedge or a very old roadside wall of soil all grown over by hedges, vines and other plants. The Brown Hairstreak extinction in eastern counties is blamed on this loss. I once read that even where hedgerows remain, machine cutting and trimming is suspected of destroying overwintering eggs on blackthorn.
