OutdoorNebraska

47 GUIDE TO NEBRASKA'S WETLANDS meadows become drier, allowing tree invasion or agricultural, commercial, and residential development. Impoundment and diversion of river water and water- borne sediment are the main factors that have and continue to cause shifts from a wide, shallow, and open channel to a narrow, deep channel surrounded by upland or wetland with woody vegetation. Failure to address these stream fl ow issues within the Platte River will continue to threaten the river and the fi sh and wildlife that depend on it. The spread of invasive purple loosestrife and European common reed is an additional threat. Both species are introduced plants of little value to wildlife and outcompete desirable native plants. Wetlands along the Central Platte River were given a Priority 1 ranking (due to very extensive past losses) in the Nebraska Wetlands Priority Plan (Gersib 1991). Benefi ts The Central Platte provides habitat for several state and federally threatened and endangered species. The state and federally endangered whooping crane uses the river during spring and fall migration, and the portion of the Central Platte from Lexington to Shelton has been designated as critical habitat necessary for the survival and recovery of this species. Recently there have been some large numbers of whooping cranes stopping along the Platte during their fall migration, including 46 observed in the fall of 2021. The state endangered least tern and the state and federally threatened piping plover have in the past been found to nest on some of the remaining unvegetated sandbars in the river. Least terns and piping plovers have mostly shifted to nesting around sand and gravel mining areas and off channel habitats created by the Platte River Recovery and Implementation Program, but both species still use the river for foraging habitat. The Central Platte River is a Biologically Unique Landscape (Schneider et al. 2011). During the spring, over one million sandhill cranes, comprising 80-85% of the mid-continent population, have been counted in this reach of the river (Caven et al. 2020). They converge here to rest and accumulate fat reserves for later migration and nesting (U.S. Fish and Wildlife Service 1981). Seven to 10 million ducks and geese, including snow geese, Ross's geese, greater white-fronted geese, Canada geese, cackling geese, mallards, and northern pintails stop over along the Platte River and in nearby Rainwater Basin wetlands. Average mid-winter waterfowl counts, 1998- 2017, were 7,500 mallards and 8,000 Canada Geese in the stretch of river from Gothenburg to Central City (Nebraska Game and Parks Commission, unpubl. data). This reach also provides habitat for migrant wading birds and shorebirds and several nesting colonies of great blue herons. More than 300 bird species have been observed along the Central Platte River, and 141 species have nested in the area. Over half of the 300 species are neotropical migrants that winter largely south of the Tropic of Cancer, but nest north of the tropics (Lingle 1994). A report issued by the National Audubon Society focused on the importance of the Central Platte as wildlife habitat, especially for migratory birds, and the complexities of managing this severely threatened system (Safi na et al. 1989). The North American Waterfowl Management Plan lists the Central Platte River as an area of greatest continental signifi cance to North American ducks, geese, and swans (U.S. Fish and Wildlife Service, Canadian Wildlife Service, and Mexican Ministry of Environment, Natural Resources, and Fisheries 2012). During high fl ows, the Platte River recharges the underlying Ogallala Aquifer, which provides irrigation water for thousands of acres of cropland (Burns 1981) and municipal water for most of the communities along the river. In portions where the channels are not constricted by structures (e.g., bridges and bank protection) or encroached upon by vegetation, the Platte River has an enormous capacity to carry fl oodwaters within its own banks (Safi na et al. 1989). The Platte River provides a variety of recreational opportunities. From fall 1986 to fall 1987, Nebraskans spent an estimated $51.3 million on nature-associated recreation in the Platte River Valley (Bureau of Wildlife observation is a popular activity in and around wetlands due to their abundance and diversity of life. Here a young observer is taking in the world-renowned spectacle of the spring sandhill crane migration. JENNY NGUYEN-WHEATLEY, NEBRASKALAND

• Cover