The last bird species described by Audubon, this sparrow's breeding grounds were not discovered until 1873 when its first nest was found in North Dakota. Now, Baird’s Sparrow is considered a defining feature of summer bird life for mixed-grass and fescue prairies of the northern Great Plains of North America. Its clear song, unique among songs of other Ammodramus species, gives one an indication of being in or near high-high quality prairie. Once considered among the most common of prairie birds, Baird’s Sparrow is now rare throughout its range and only locally abundant depending on the condition of grasslands. Agriculture has eliminated much of its former range and continues to reduce remaining grassland tracts. This species was formerly thought an exclusive denizen of native grasses, but recent research reveals an acceptance of formerly cultivated lands with structural components resembling native prairie, and in agricultural use such as hayfields or pastures with strong incursions or plantings of non-native grasses. Actively cultivated lands, while used to some degree, are clearly unproductive for this species, however, and are likely responsible for population declines in this species.
Baird’s Sparrow appears partially nomadic, sometimes exhibiting dramatic shifts in population densities from one year to the next. Such behaviors are likely an evolved response to shifting habitat suitability due to the unpredictable but common influences of fire, drought, and the movements and grazing of bison (Bison bison) herds.
The distribution and biology of Baird’s Sparrow on its wintering grounds in southern US (Arizona, New Mexico, Texas) and northern Mexico (Sonora, Chihuahua, Durango and Zacatacas) are still poorly understood and little studied.