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Platte River Status: A common migrant, fairly common and local summer resident. Extreme dates of occurrence at the Mormon Island Crane Meadows, Hall County, are 6 April to 25 November. Savannah sparrow is a common migrant in Lincoln County (Tout 1947). A flock of "thousands" was found at North Platte 11 May 1938. Rosche (1979) recorded savannah sparrow twice on migration in the lower North Platte River Valley.

Breeding Range: Apparently restricted to the Eastern Plain and Dissected Plain physiographic regions. We expect this sparrow to occur in the Platte River Valley physiographic region during the nesting season where habitat conditions are suitable.

Breeding Population: The estimated population in 1979-1980 was 1,290 breeding pairs.

Habitat: We found a mean breeding density of <0.1 pairs/km² in upland prairie. The singing males we recorded were all in low, wet depressions in the grasslands. Kantrud and Kologiski (1982) stated that savannah sparrows in the northern Great Plains occur during the nesting season primarily in lightly to moderately grazed grasslands developed over cool, moist northern soils. Dominant plant species in savannah sparrow territories on the northern Great Plains were Junegrass, Kentucky bluegrass, fringed sage, and white sage. Faanes (1982) found savannah sparrow an abundant nesting species in central North Dakota wet meadows. This species was less common and more localized in wetter portions of dried seasonally flooded wetlands. That wet meadow vegetation is used for nesting more frequently in arid regions of the species range is demonstrated by Godfrey (1950), Salt and Salt (1976), South Dakota Ornithologist's Union (1978) and Maher (1979). Graber and Graber (1963) found savannah sparrow in all grassland types in northern and central Illinois; highest densities were in mowed hay (96 birds/km²) and shrub areas.

Effect of Habitat Alteration: Loss of wet meadow areas through groundwater drawdown brought on be expanded pivot irrigation has been detrimental to this species, especially in the Sandhills. Intensive grazing of grassland areas also produces a negative impact on this species.

Nesting Data: We have no confirmed nest records from the Platte River Valley. North Dakota egg dates range from 28 May to 9 July.