Studies have shown that plants in fragmented habitats are visited left often by pollinators and have fewer seeds and hence lower reproduction. This inability to find the plant also is detrimental to the pollinator as they often require specific plants on which to feed. Finally, as a woodlot gets smaller its edge to interior area ratio increases. This 'edge effect' can reduce species abundance. Predation has been shown to be higher along edges of woodlots.
Cowbirds show higher parasitism of nests in small woodlots compared to larger ones.
Cowbirds, lay their eggs in the nests of other birds and the hosts then raise the demanding cowbird chick as their own, often neglecting their own offspring. It is thought that fragmented areas provide better foraging for cowbirds, compared to a large interior forest area. Mammals, snakes and Bluejays also may hunt along edges, and predation has been shown to be higher in small woodlots. Loss of good interior forest habitat is thought to be the reason for a decline in songbirds such as the Wood Thrush, Acadian Flycatcher and the Hooded Warbler. The presence of sensitive, forest interior birds such as the Scarlet Tanger or Ovenbird are an indicator of good, undisturbed forest habitat.