Importance of Early Successional Habitats to Mammals in Eastern Forests

• Published in: Wildlife Society bulletin 2001-07, Vol.29 (2), p.466-473
• Main Author: Litvaitis, John A.
• Format: Article
• Language: English
• Subjects: Animal populations; Bats; Environmental impact; Forest ecology; Forest habitats; Forest stands; Forest succession; Forests; Habitat conservation; Habitat corridors; Habitats; Mammalia; Mammals; Special Coverage: Conservation of Woody, Early Successional Habitats and Wildlife in the Eastern United States; Wildlife habitats; Wildlife management
• ISSN: 0091-7648; 1938-5463

Populations of mammals that depend on early successional forests or shrub-dominated habitats are declining in portions of the eastern United States. Although much of this decline can be attributed to maturation of young forests that once dominated the East, fragmentation and suppression of natural disturbances also have been implicated. Responses by habitat specialists (e.g., New England cottontails [Sylvilagus transitionalis]) and carnivores with large area requirements that rely on prey associated with early successional habitats (e.g., bobcats [Lynx rufus]) have been most extreme. Populations of facultative or opportunistic users of early successional habitats (e.g., black bears [Ursus americanus] and little brown bats [Myotis lucifugus]) apparently have not been affected by fewer young stands. As eastern forests mature, biotic and abiotic forces will increase abundance of early successional habitats. However, maturation of these forests will take a century or more. In the meantime, using even-aged silviculture and applying controlled burns to native shrublands may be useful to alleviate current shortages. In landscapes modified substantially by suburban-urban developments and dense networks of roads, conventional management efforts likely will be insufficient. In these regions, increased populations of generalist predators are capable of exerting intense predation on mammalian herbivores that are restricted to small patches, and movement between patches by small mammals is limited. Mammals with large area requirements also are hampered in these landscapes by frequent road crossings. These limitations may require implementing habitat management programs for mammals that differ from those developed for other disturbance-dependent taxa. Large (>10-ha), clustered patches of early successional habitat may be necessary to maintain viable populations. The effectiveness of these managed habitats will be further enhanced by positioning them close to existing land uses that are characterized by early successional habitats (e.g., powerline corridors). In agricultural landscapes, the representation of old-field habitats could be increased in set-aside programs.