Unlike other regions of North America, forested habitats in New England have increased substantially in the past 100 years. The proportion of land in New Hampsbire covered by forests was 47% in 1880 and 87% in 1980. This increase was largely the result of a region-wide abandonment of farms and the subsequent colonization of these lands by second-growth forests. I examined the sequence of farm abandonment, forest colonization, and forest maturation that occurred in New Hampshire in relation to changes in the abundance and distribution of a group of forest mammals and birds that have undergone substantial declines. A modeled pattern of secondary succession resulted in the availability of approximately 195,000 ha of early seral habitats (10-25 years after abandonment) from 1905 to 1940 These habitats then matured into closed-canopy forests by about 1960. Concurrent to the loss of early successional habitats, populations of New England cottontails (Sylvilagus transitionalis) decreased from an apparent continuous distribution throughout 60% of New Hampshire to fragmented populations that occupy less than 20% of the state. Bobcats (Felis rufus) responded functionally (S. transitionalis in diet: 1951-1954 = 43%, 1961-1964 = 10%) and numerically (mean annual harvest of bobcats: 1951-1954 = 350, 1965-1969 = 36) to changes in cottontail abundance. Eighteen of 26 species of migratory passerines that nest in the forests of northern New England also declined during the period their populations were monitored (1934-1987). Eight (44%) of the species that declined are associated with early successional habitats, and these species consistently exhibited population declines during the 1950s. The reduction of early successional species may be extended in space and time by current land uses that fragment and isolate patches of habitat. Ownership patterns of forest lands in New England (excluding Maine) reveal 88% private ownership with an average bolding of 10 ba This suggests that large tracts of early successional habitats will be restricted to industrial and state/national forests. Although even-aged management of a portion of these forests may be perceived as incompatible with area-sensitive and interior species, clustering of clearcuts and maintaining large tracts of mature habitats could sustain diverse populations of forest vertebrates.
