Many forest-breeding birds are sensitive to habitat fragmentation, showing poor reproductive success, poor mating success, declining populations, or even local extinction in fragmented landscapes.
Forest fragmentation affects bird populations through both edge effects and area affects.
Edge effects include nest parasitism and increased predation. Area effects include reduced mating success, reduced patch-specific productivity, and reduced habitat diversity. These processes are likely to operate on different scales. Historically, avian response to habitat fragmentation has been measured at the population or patch-level. More recently research has focused on collecting habitat-specific demographic data.