Abundant in Sax-Zim! Should it be Minnesota’s State Bird?
This nesting season, Welcome Center Host/Naturalist Jason Heinen spent much of June documenting Vermivora chrysoptera (Golden-winged Warbler) abundance in the greater Sax-Zim Bog IBA. The Golden-winged Warbler is a species of conservation concern and is currently listed as Near Threatened by the IUCN. Although Minnesota represents a stronghold for their global population during the breeding season, these birds have lost an estimated 22% of their nesting habitat in the Great Lakes region since the 1960s (Cornell Lab of Ornithology 2013). This species has declined rapidly throughout much of its range (>9% declines annually in our region from 1994-2003) due to a variety of factors including early successional habitat maturation, loss of wetland habitat, and human encroachment (Buehler et. al 2006). Because Golden-winged Warblers depend greatly upon young forests, wet shrublands and mature forest edge, they are an excellent candidate for novel and continued conservation-forward forest management practices in our region.
During our survey period, approximately 250 miles were surveyed by car, and 96 singing males were documented. This translates to roughly one territory every 2.6 miles. Roadways where agricultural lands or contiguous old growth forests dominated either side of the road were largely ignored, as this habitat is less than ideal. This means that within suitable habitat, the densities of golden-wings was much higher. Seven of the mapped points had multiple males counter-singing. As expected, territories primarily occurred where more mature mixed forests met early successional growth and open, wet shrublands. Grassy roadside and railroad buffer strips were also common locations for males to set up territories, as long as these were within a forested habitat matrix.
If this Friends of Sax-Zim Bog pilot study continues into the coming years, we hope that it may help inform future conservation plans for this and other imperiled species like Connecticut Warbler and LeConte’s Sparrows within the Sax-Zim Bog IBA and beyond. By expanding our knowledge of these species in the bog and compiling future data for years to come, we will be in a position to aid in conservation for these important species. We should also be able to expand education and outreach opportunities through training and experience for seasonal field researchers, volunteers, and school groups.
