Response of breeding birds to shearing and burning in wetland brush ecosystems

In the absence of wildfire, emergent wetlands in the American Midwest often succeed to a shrub/scrub wetland type. Management activities, including sh earing and burning are typically used to remove shrub, resulting in a more open emergent wetland condition. We surveyed breeding birds in managed and unmanaged shrub/scrub wetlands in northeast Minnesota, USA, in 1996 and 199 7 to examine breeding bird response to management type (burning and shearin g) and time elapsed since management. In a comparison of 58 managed sites a nd 58 unmanaged sites in 1996, unmanaged sites had more (P < 0.05) species and individuals than managed sites. In addition, 12 of 20 individual specie s tested differed significantly (P < 0.05) in abundance between the groups. Species associated with emergent wetland type, like the Sedge Wren (Cistot horus platensis) and LeConte's Sparrow (Ammodramus leconteii) were more abu ndant (P < 0.05) in managed sites, and species that require shrubs, such as the Alder Flycatcher (Empidonax alnorum) and Golden-winged Warbler (Vermiv ora chrysoptera) were more abundant (P < 0.05) in unmanaged sites. Examinat ion of the effects of management type on breeding birds by either burning, shearing, or both treatments on sites surveyed in 1997 revealed results sim ilar to comparisons of managed and unmanaged sites completed in 1996. In ad dition, breeding bird composition was not different on sites that varied in time elapsed since management. In these latter comparisons, breeding bird species and community composition were similar among all managed sites but differed from the unmanaged sites.