Summary of Breeding Bird Trends in the Chippewa and Superior National Forests of Minnesota: 1995-2012

Abstract

The breeding bird communities of the western Great Lakes region have among the richest diversity of breeding bird species in North America (Green 1995, Howe et al. 1997, Rich et al. 2004). The importance of this diversity and past concerns with potential declines of some species has led to a strong interest in monitoring forest bird populations in the region. The relatively heavily forested landscapes of northern Minnesota and Wisconsin are considered to be population 'sources' for many forest bird species and may be supplementing population 'sinks' in the agricultural landscapes of the lower Midwest (Robinson et al. 1995, Temple and Flaspohler 1998). Analysis of population trends is used as an 'early-warning system' of potential problems in a species population and serves as a measure of the ecological condition of the environment (Niemi and McDonald 2004a). Recently, a draft of a general technical report on a summary of the twenty-plus year data that have been gathered in the Chequamegon, Chippewa, Nicolet, and Superior NFs from the late 1980s through 2011 has been completed (Niemi et al. 2013). This report is due for publication during the spring of 2013. It summarizes a substantial amount of information that has been gathered on population trends, habitat relationships, bird community assemblages, factors potentially affecting population trends, management recommendations for bird species of concern, and a brief review of potential invasive species affecting bird species. Large-scale population monitoring programs such as the U.S. Geological Survey’s Breeding Bird Survey (BBS) provide important information on trends at a continental scale. However, limited coverage in some areas can make it difficult to use BBS data to characterize population trends at smaller geographic scales (Peterjohn et al. 1995). Continental trends also have the potential to mask regional population trends (Holmes and Sherry 1988), thus there is a need for regional monitoring programs that can provide more localized information (Howe et al. 1997). In response to the need for regional population data, a long-term forest breeding bird monitoring program was established in 1991 in the Chippewa and Superior NFs. The Forest Service is mandated to monitor certain management indicator species (Manley et al. 1993), and our monitoring program expands beyond indicator species to include all forest songbird species that we can adequately sample. Currently, approximately 314 stands (942 points) within the two NFs are surveyed during the breeding season (June 1 to July 10). The primary objective of this report is to update U.S. Forest Service personnel on results of the forest bird monitoring program. Here we focus on relative abundance trends of individual species during the period from 1995-2012 (18 years) and summarize the most important recent results.