The Upper Mississippi National Wildlife Refuge IBA follows the purchase boundaries of the Upper Mississippi River National Wildlife and Fish Refuge (Figure 1) from the Minnesota-Iowa border at river mile 674 upstream along the Mississippi River to Reads Landing, MN (river mile 763.5) (Figure 2). The IBA includes Pools 4, 5, 5a, 6, 7, 8, and part of 9 (in refuge Districts Winona, La Crosse and McGregor) (Figures 3 ? 9). It is accessible by U.S. Hwy 61 which runs along its length. Bordered by numerous towns including LaCrescent, Winona, and Wabasha as well as private and state lands, the refuge is subject to a multitude of influences and threats.
The Upper Mississippi NWR is the longest NWR in the lower 48 states. It extends 261 miles along the Mississippi River from the Chippewa River in Wisconsin to nearly Rock Island, Illinois (Fig. 1). Habitat types include bottomland hardwood forest, river, open pools, cliff, and backwater habitats. The Refuge was established in 1924 to protect bottomland habitat for migratory birds and fish. The 242,400-acre refuge lies within Minnesota, Wisconsin, Iowa, and Illinois and is divided into four management districts.
With an estimated 3.7 million annual visitors, it is the most heavily visited Refuge in the System. It has interface with 4 states, 70 communities, 2 Corps of Engineers districts, 11 locks and dams which help maintain water depths for commercial navigation, and is represented in Congress by 8 senators and 6 representatives.
The Upper Mississippi Valley provides habitat for 305 species of birds, 57 species of mammals, 45 species of amphibians and reptiles, and 134 species of fish. Major furbearers along the Mississippi River include muskrat, mink, beaver, otter, raccoon, skunk, weasel and fox. Other mammals include gray and fox squirrels, cottontails, jackrabbits and white-tailed deer which are abundant in the timbered areas.
This Important Bird Area meets the minimum requirements to qualify under criteria 1a, 1c, 1d, 1e, 2a, 2b and 3. It is an important site for migrating waterfowl, particularly Canvasbacks and Tundra Swans as well as nesting waterbirds, and breeding and wintering Bald Eagles. Data is often collected across state boundaries, or by pool. Where possible data cited below is limited to the Minnesota portion of the river, however this is often impractical, and biologically illogical.
MN ?V 1a The Mississippi River is a significant bird migration route and among the more spectacular seasonal flights are those of the waterfowl. It has been estimated that up to 40% of the nations waterfowl and shorebirds use the river valley during spring and fall migration. Nineteen species of waterfowl have been recorded during fall migration on the Upper Mississippi River NWR. Among the most notable fall concentrations are those of Canvasbacks, representing up to 50% of the continental population, and Tundra Swans with an estimated 20% of the eastern North American population. Tundra Swans (daily totals over 20,000 in pools 4-9) are a popular attraction for many bird watchers attracting viewers to towns along the river. Diving ducks such as Redheads, Buffleheads, and Ruddy Ducks gather in open water, while American Wigeon, Gadwall, teal and other puddle ducks are found in the shallow backwaters.
Daily high waterfowl counts in fall 2005 exceeded 600,000 birds in pools 4-9. Significant 2005 daily high counts for selected individual species were: Canvasbacks (356,630); scaup (>135,000), Ring-necked Ducks (approx. 30,000), and Mallards (>41,000).
MN ?V 1c Fifteen to twenty waterbird nesting colonies are found on the refuge containing over 5,000 nests. On pools 4-8 the number of nesting Great Blue Herons ranged from 786 ?V 1,306 pairs between 1999 - 2002.
MN ?V 1d The Mississippi River is one of the most important Bald Eagle wintering areas in North America. While the number of wintering eagles in Minnesota is not as high as portions of the river further south, the locks and dam system and wooded cliffs do provided excellent winter Bald Eagle habitat. Bald Eagle wintering numbers on this IBA vary both between, and within, years depending on weather and ice cover. Mid-winter counts ranged from 321 in 2004 to 58 in 2005 between Winona and LaCrescent, as viewed from the Minnesota side of the river. Winter eagle roosts are located at Read??s Landing and Whitman Dam.
MN ?V 1e The Upper Mississippi Valley NWR has recorded 305 species of birds, 133 of which are known to breed. This includes 29 species of shorebirds and 33 species of warblers (10 breeding).
MN ?V 2a The refuge has recorded 18 criteria 2a species. Detailed information is available only for Bald Eagles, Peregrine Falcons, and Red-shouldered Hawks. In addition to winter eagle use documented under 1d, the refuge had 150 active Bald Eagle nests in 2005, 36 of which were located in Minnesota. Peregrine Falcons nest on cliffs located just outside the refuge boundary but certainly hunt within the IBA. Red-shouldered Hawks nest in the refuge and up to 24 pairs have been recorded in one year.
MN ?V 2b Twenty-seven criteria 2b species occur on the refuge. Up to 50% of the world??s Canvasbacks stage on the refuge every fall. Prothonotary Warblers occur at a density of about 0.75 pr/ha.
MN ?V 3 The refuge contains significant acreages of Floodplain Forest with 21 species associated with this habitat having been recorded.
Introduced zebra mussels threaten native mussels, clams and snails, while
introduced purple loosestrife is responsible for the degradation of many prime wetland habitats; biological
control has been instituted to combat it. Upland erosion, channel operation and maintenance, and tow
traffic along the river continue to cause degradation and loss of habitat. Sediment deposition and both
point and non-point pollution also threaten the biological integrity of habitats along the river. The refuge
is heavily used by hunters, fishers and other recreationists.