A Critical Analysis on the Use of Indicator Species in Management

Abstract

We examined the habitat distributions of management indicator and sensitive species (MIS), as defined by the U.S. Forest Service within the Chequamegon National Forest (CNF) of northern Wisconsin and whether other bird species were positively associated with these MIS. We addressed these associations with 2 relatively large databases, annual breeding bird counts of 92 line transect segments gathered from 1986 to 1992 and counts of 122 Forest Stands gathered in 1992-1993. Of 25 MIS identified by the CNF, only 7 species were abundant enough for analyses. The other species were either too rare within the CNF or the censusing methods were not compatible with their life history. Only 2 of the MIS had nonrandom distributions associated with specific habitat types and warranted consideration as indicators. The yellow-bellied flycatcher (Empidonax flaviventris) was found primarily in lowland coniferous habitats, while the pine warbler (Dendroica pinus) was found primarily in upland coniferous habitats, especially pine. Although many positive species associations were found for most of the MIS, many inconsistencies among the 2 datasets also were identified. Most species responded to habitat attributes that satisfy their needs for survival and these autecological responses likely led to inconsistent patterns of species associations for most of the MIS. The lack of consistent patterns among most MIS casts doubt on the ability to use a few species as indicators for the well-being of many other species, especially for those that are uncommon and difficult to monitor. Developing more comprehensive techniques that improve habitat classifications and combine monitoring of trends in habitat and birds within those habitats likely will prove more fruitful than focusing on a few representative species.