With the exception of salt marshes and beaver meadows, almost every field, pasture, and meadow in the Connecticut River watershed has been created by human activity. Native Americans used fire to clear forest, and European settlers went to work in earnest to clear land for livestock and crops. By the mid 1800's most of southern and central New England had been deforested. Grassland nesting birds and other "early successional" species like meadow voles, and rabbits, and many butterflies benefited.
As improved transportation systems developed in the late 1800's, agricultural
production shifted to the Midwest and many New England farms were abandoned.
Forests began reclaiming open land. Open field are also often lost to development.
Over time, there are fewer and fewer fields for grasslands species.