Golden-winged warbler demography and habitat associations in Minnesota

Principal Investigator: David E. Andersen.

Student: Sean Peterson, M.S. (Natural Resources Science and Management, Wildlife Ecology and Management Track).

Post-doctoral Research Fellow: Henry M. Streby

Status: Project initiated in 2012 as part of a larger, regional project on golden-winged warblers in the western Great Lakes Region. Project completed November 2013.

At least 40% of the global population of golden-winged warblers (Vermivora chrysoptera) nests in Minnesota. No other bird species has such a large concentration of its global population breeding in Minnesota. Furthermore, Minnesota is the only state in which golden-winged warbler populations have been experiencing a positive growth trend over the past decade, presenting a strong stewardship responsibility for the state. Although we have found golden-winged warblers use more mature forest than previously known, they depend on relatively open cover types such as early-successional forest stands, open forested wetlands, and lowland shrubby areas within a mature forest matrix as primary nesting areas. Golden-winged warbler nesting habitat is in decline, particularly in eastern portions of the species’ breeding distribution (Appalachian Mountains), as abandoned farmlands regenerate to mature forest, timber harvest declines, and wetlands are drained for development. There is currently considerable debate about the desired future composition and juxtaposition of habitats within the northern hardwood-coniferous forests of Minnesota and nearby states, a bioregion predicted to be among the earliest and most dramatically affected by global climate change. Considerations for wildlife, including songbirds of conservation concern, are an important part of this conversation. Information about golden-winged warbler survival and habitat use throughout the nesting period is limited, and almost nothing is known about these parameters during the post-fledging period. Assessing the demographic response of golden-winged warbler populations to land management and other habitat alterations is critical for the conservation of this species.

The study, which began in 2012, investigates golden-winged warbler survival and productivity (both nest productivity and fledgling survival) in their primary breeding habitat types (early-successional forests and shrubby forested wetlands) at Tamarac National Wildlife Refuge (NWR) in northern Minnesota, Rice Lake National Wildlife Refuge (NWR) in eastern Minnesota, and Sandilands Provincial Forest (PF) in Manitoba (work at PF is supported with distinct funds from another source). We will use these demographic data to build predictive models of seasonal productivity and population growth and provide management recommendations for maximizing habitat characteristics, at multiple spatial scales, associated with increased population growth for golden-winged warblers.