For example, the Albany pine bush once covered 40,000 contiguous acres. Development has now reduced it to 2,000 acres, subdivided by roads, buildings and other obstacles to butterflies. The New Hampshire pine barrens have been largely destroyed by development. Even in Wisconsin, fragmentation, agricultural development, urban encroachment, and other destruction threatens remaining Karner blue habitat. These uses make for small, isolated Karner blue populations that are more vulnerable to extinction by factors like droughts or other catastrophes.
Butterflies are also very sensitive to climatic conditions.
Already, due to global climate change, many butterfly species are being driven north of their typical ranges in search of cooler temperatures, making habitat protection yet more complex for them. Once fragmented, Karner blue populations dwindle away, with one local extinction following another. The decline of the Karner blue butterfly, like the decline of most other endangered and threatened species, is a sign that large expanses of habitat have been severely damaged or completely paved over by our growing population. These lost areas do not affect the butterfly alone, but they also threaten to create long-term impacts on the economic, agricultural, and aesthetic value of these areas. But fortunately, it does not have to be too late for the Karner blue butterfly.