Bird communities of early-successional burned and logged forest

Because logging has replaced fire as the most extensive and frequent disturbance regime in northeastern Minnesota, monitoring bird populations and their habitats has become increasingly important. We surveyed early-successional forests created by fire or logging for birds and their habitat during the 1994 and 1995 breeding seasons. We found that overall bird species richness and number of individuals (territorial males/ha) were higher (P < 0.05) in burned forests than in logged forests. The American crow (Corvus brachyrhynchos), house wren (Troglodytes aedon), common yellowthroat (Geothlypis trichas), clay-colored sparrow (Spizella pallida), song sparrow (Melospiza melodia), Lincoln's sparrow (M. lincolnii), and brown-headed cowbird (Molothrus ater) were more abundant in burned areas. The Nashville warbler (Vermivora ruficapilla), chestnut-sided warbler (Dendroica pensylvanica), black-throated green warbler (D. virens), and mourning warbler (Oporornis agilis) were present in greater numbers in the logged areas. We related these differences in bird presence and abundance to vegetation differences in the burned and logged habitat types. Burned areas had higher densities of dead trees, wider size ranges of dead trees, and greater heterogeneity in the shrub layer. Logged areas had higher densities of live trees, more live tree species, and wider size ranges of live trees. Red maple (Acer rubrum) was the live tree species found in greatest abundance in logged areas. If management goals include simulating natural disturbances like fire and maintaining bird populations, more dead trees should be left within logged habitats and the variability among logged areas should be increased.