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Birdwatching at Agassiz NWR, an Important Bird Area in MinnesotaSee bitterns, Black Terns, and tens of thousands of Franklin's Gulls at Minnesota's Agassiz National Wildlife Refuge
Published: April 20, 2007 I sat anxiously at the water's edge in northwestern Minnesota near wildlife biologist Gary Huschle, waiting for an American Bittern to exit the box. The bird had been trapped earlier in the day and outfitted with a leg band and a radio transmitter. Huschle was about to release the bittern within the territory where it had been captured.
He explained that sometimes a newly banded bittern will flush directly from the box and into the marsh. Other times, it will walk slowly, offering the chance for a memorable photo. I was not to be disappointed. The bittern stepped out of the box, turned toward me only four feet away, raised its bill skyward, and stared at me with the strangely fierce and prehistoric look unique to bitterns. At such close range, I could see the thin wire antenna of its new radio transmitter curving around its neck. Considering its three-inch, spear-like bill, I hoped the bird was not thinking that I was guilty of the indignities it had just experienced. Ever so slowly, the bittern finally turned away, stalked toward the water, flushed, and disappeared into the nearby marsh.
Huschle was studying the bird's habitat preferences and migratory patterns at a place that I consider to be the bittern capital of Minnesota: Agassiz National Wildlife Refuge. Located only 40 miles south of the Manitoba border, it occupies a transitional area between coniferous forests to the east and prairies and wetlands to the west. As a result, Agassiz attracts lots of birds - 294 species - and consequently is a fantastic birding destination.
My birding experiences at Agassiz go back to June 11, 1980, when I drove through the refuge with biologist Jim Mattson. Our highlight of the day was a Yellow-crowned Night-Heron, the first record ever for the species on the refuge. Every trip since then has been memorable. And though I think only of finding birds whenever I visit, I know that without the dedication of conservationists long ago, I would find few birds in this remote corner of the state today.
Throughout the 1800s, the area's grasslands and wetlands supported thousands of ducks, geese, Trumpeter Swans, cranes, songbirds, Sharp-tailed Grouse, wolves, elk, bear, and moose. From 1910 to 1915, settlers tried to establish farms by digging drainage canals, and wildlife suffered. By the 1930s, only about three dozen Sandhill Cranes were left in the region, and nesting Trumpeter Swans and Whooping Cranes were long gone.
The Great Depression and a regionwide drought forced farmers into bankruptcy, and in time, the state of Minnesota conservation agency (now the Department of Natural Resources) took control of the drainage basin. Local hunters and the national Izaak Walton League urged the creation of a migratory bird sanctuary. Eventually more than 55,000 acres made up what was named the Mud Lake Refuge. |
Saved for waterfowl
Minnesota soon arranged to transfer the land to federal hands, and in 1937, President Franklin Roosevelt designated it the Mud Lake Migratory Waterfowl Refuge. It was renamed in 1961 the Agassiz National Wildlife Refuge to recognize the significance of Glacial Lake Agassiz, an enormous post-glaciation era lake that created the region's vast flat terrain. Over the past 70 years, the refuge has seen the restoration of wetlands, forests, and grasslands and has increased to 61,500 acres in all.
The refuge is managed to provide ideal wildlife habitat. Marsh drawdowns rejuvenate wetlands, prescribed burns maintain prairie grasses, former croplands are replanted with prairie grasses and wildflowers, and invasive and exotic plant species are controlled.
The land's recovery has been remarkable. Agassiz is considered a Globally Important Bird Area, meaning that it is a place of significant importance to birds during at least part of the year. The primary reason for the designation is that Agassiz is home to one of the largest colonies of Franklin's Gulls in the world. In a good year, 20,000 to 40,000 pairs nest at the refuge.
Other species that breed in large numbers include Black-crowned Night-Heron (about 900 pairs), Black Tern (750 pairs), Eared Grebe (up to 500 pairs), Forster's Tern (common), and untold numbers of American and Least Bitterns. In addition, 3,000 to 5,000 non-breeding American White Pelicans occur on the refuge. And up to four of the Eared Grebe's relatives arrive in spring: Pied-billed, Red-necked, Horned, and Western.
The refuge also is a mecca for waterfowl, including Canvasback, Redhead, Ring-necked Duck, Northern Pintail, Northern Shoveler, Blue-winged and Green-winged Teal, Gadwall, American Wigeon, Ruddy Duck, Hooded Merganser, and Canada Goose. Approximately 7,000 pairs of ducks and 600 pairs of geese nest across the refuge, and up to 50,000 ducks, 23,000 geese, 200 Tundra Swans, and 2,000 Greater Sandhill Cranes stop over during fall migration. |
Trumpeter Swans are back
Aspen parklands in the refuge provide habitat for cranes, Short-eared Owls, Northern Harriers, Black-billed Magpies, Common Ravens, Sharp-tailed Grouse, Ruffed Grouse, and Gray Jays. Bald Eagles began nesting for the first time in 30 years in 1992. In 2004 a pair of Trumpeter Swans raised a family at Agassiz for the first time in more than 100 years; a second pair joined them last summer. Woodland species include Black-throated Green and Cape May Warblers, Harris's and White-crowned Sparrows, and the occasional Scarlet Tanager.
Visitors can watch birds from an auto tour route and along County Road 7 near the refuge's south boundary. And don't be quick to leave. Refuge Manager Maggie Anderson suggests sticking around to hear Agassiz.
"If you park along County Road 7 along the main refuge pool at night, you can hear an awesome chorus of grebes, rails, frogs, geese, and ducks," she says. "Sometimes it is possible to hear timber wolves howling, and if you're really lucky, the northern lights come out."
As you allow yourself to get lost in the sights and sounds of this wild, remote scene, remember too what you've left behind: powerlines, highway traffic, crowds. "At Agassiz," says Anderson, "bird-filled skies and natural habitats extend all the way to the horizon."
Carrol L. Henderson is the nongame wildlife program supervisor of the Minnesota Department of Natural Resources, the author of seven books, and a frequent contributor to Birder's World. |
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Agassiz National Wildlife Refuge is one of 23 Important Bird Areas in Minnesota and is part of the Pine to Prairie Birding Trail.
Birds: 294 species
Size: 61,500 acres
Habitat: Large pools, marshes, grassland, brushland, aspen woodlands
Amenities: Auto tour route, observation tower, two hiking trails, interpretive center. Checklist and refuge map available. |
Last Whoopers
Thief Lake, a state-owned wildlife management area just north of Agassiz National Wildlife Refuge, holds a notable spot in ornithological history. It was the site of the last known Whooping Crane nest in Minnesota. An egg collector removed two eggs from it in June 1889.
After that, the only other Whooping Crane nest ever found in the United States was located in Hancock County, Iowa, in 1894. (In recent years, reintroduced cranes have nested in Florida and Wisconsin.)
Whoopers were reported in southern, western, and northwestern Minnesota sporadically in the 1890s, and two cranes were shot in Roseau County near the boundary with Manitoba in April 1917.
But a hopeful sign that the species could one day reclaim Minnesota came in 1990. That year, a single crane was seen less than a mile outside the Agassiz refuge.
Source: Allen, Robert P., 1952, The Whooping Crane. National Audubon Society Research Report No. 3. |
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