Shiawassee National Wildlife Refuge is the most reliable place in Michigan to find the prothonotary warbler. - Photo by Larry Abraham.

Sandhill cranes started nesting at Shiawassee National Wildlife Refuge refuge in 2004. - USFWS photo by Edward P. De Vries

Shiawassee National Wildlife Refuge was established primarily because of the value of the area’s diverse riparian wetlands as a stopover site for birds during migration.  However, the refuge provides important habitat for nesting birds as well.  In fact, fieldwork for the second Michigan Breeding Bird Atlas (MBBA II), completed 2002-2008, documented that the greatest diversity of nesting birds in the state occurs at Shiawassee National Wildlife Refuge.

Nesting evidence was recorded for a total of 134 species at the refuge.  This great diversity is due in large part to the refuge’s diversity of habitats.  Emergent marsh areas support declining marshbirds including American bittern, least bittern, black tern, common moorhen, marsh wren, and swamp sparrow.  Large blocks of contiguous forested wetland provide habitat for hooded merganser, yellow-billed cuckoo, red-bellied woodpecker, yellow-throated vireo, wood thrush, and prothonotary warbler.  Sedge wren and bobolink utilize grassland and prairie habitats.  American woodcock, willow flycatcher, brown thrasher, and indigo bunting find quality habitat in shrub dominated areas.  All of these species are state-listed or Partners In Flight priority species.

Several other noteworthy aspects of the refuge’s avifauna were documented via MBBA II.  Three new breeding species for the refuge were confirmed, including sandhill crane, yellow-bellied sapsucker, and vesper sparrow.  Wild turkey, pileated woodpecker, and cliff swallow were unrecorded on the refuge during the first atlas, but both are now common refuge breeders.  Also, the greatest density of nesting wood ducks in the state was found on the refuge.  Sadly, one species that seems to have faded from the refuge’s breeding bird community is yellow-headed blackbird.  This species was confirmed as a refuge breeder during the first atlas, but was not found at all on the refuge during MBBA II.

MBBA II replicated the efforts of birdwatchers in the 1980s who surveyed the entire state in a massive effort to map the distribution of birds which breed in Michigan.  This information has proved invaluable to scientists and natural resource managers.  The atlas was coordinated by the Kalamazoo Nature Center.  Major funding was provided by the Michigan Department of Natural Resources, supplemented by the U.S. Fish and Wildlife Service.