Ammodramus bairdii (Audubon, 1844)
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Basis for Listing
The breeding range of the Baird's sparrow is restricted to the northern Great Plains states and the southern Canadian Prairie Provinces. In Minnesota this species was probably never very abundant, breeding only in the Red River valley from Traverse County north to the Canadian border. By the 1920s, the Baird's sparrow was common only in dry prairie habitat of the Upper Red River valley. By the 1960s it had become very rare in Minnesota, with the vast majority of records coming from the Felton Prairie area in Clay County. This scarcity led to the Baird's sparrow's classification as endangered in Minnesota in 1984.
The Baird's sparrow is similar in appearance to several other sparrows, but can be identified by the dull orange color on its head and the dark streaked necklace on its breast. This species is best identified by its distinctive song, which consists of two or three high, thin introductory notes followed by a musical trill. On its breeding grounds, the bird seems reluctant to fly and more often runs through the grass if disturbed.
On the eastern periphery of its range, the Baird's sparrow prefers dry, native grassland where the grass is dense and fairly long. Farther west, in the heart of its range, it tolerates more grazing and uses a greater variety of grassland habitats. Researchers have speculated that the Baird's sparrow is ephemeral in its distribution, shifting breeding habitat in response to annual moisture conditions (Kantrud and Faanes 1979). In dry years the species tends to be found in mesic sites, whereas in wet years, drier sites are preferred.
Biology / Life History
Baird's sparrows overwinter in grasslands in Arizona, New Mexico, Texas, and northern Mexico. Males arrive on the breeding grounds in early to mid-May, before the females, and establish territories of 0.5-1.5 ha (1.2-3.7 ac.). They seem to prefer territories adjacent to each other, and it is thought that the species may be semi-colonial or polygynous. Nests are constructed in scrapes on the ground and are made of fine materials such as grasses, horse hair, and moss. They are concealed from above by tufts of overhanging grass and are very well hidden (Jones and Green 1998). Clutches of 4-5 eggs are laid in June or July. The young hatch in 11-12 days and fledge after an additional 8-11 days. They grow quickly, and two broods are sometimes produced in a summer. Baird's sparrows eat insects, spiders, and other invertebrates during summer, and seeds during winter.
Conservation / Management
Habitat preservation is the most important conservation strategy for Baird's sparrows. Efforts should be made to maintain native prairie in large tracts wherever possible. Fragmentation of prairie habitat increases the ratio of edge to interior habitat, which leads to increased numbers of predators and brown-headed cowbirds (Johnson and Temple 1990). Controlled burns that mimic natural fire intervals and help recreate native prairie conditions should be conducted. Although Baird's sparrows may not use an area immediately after it is burned, populations usually rebound within two or three years (Pylypec 1991). This species is generally absent from heavily grazed land, but will nest in moderately-grazed areas. Rotational grazing systems, which provide undisturbed areas during the nesting season, have resulted in high densities of Baird's sparrows (Messmer 1990). Mowing should be delayed until late August to avoid destroying nests. Conservation Reserve Program (CRP) land does not appear to provide suitable habitat for this species, as most land currently under this program is reseeded with non-native grasses or non-native grass-legume mixtures rather than native species. Landowners in the CRP program should be encouraged to maintain their land in such a way that it is suitable for Baird's sparrows.
Conservation Efforts in Minnesota
It is difficult to assess the population status of Baird's sparrows, due to the species current rarity in the state. However, accurate knowledge of the status of Baird's sparrows in Minnesota is necessary to plan recovery efforts for this species. Surveys of the Felton Prairie area, where Baird's sparrows are most frequently sighted, should be continued. Somewhat encouraging was the presence of two singing male Baird's sparrows in a large prairie restoration area in Polk County in 2002 (Richardson 2003). Prairie management and restoration should be continued in this area, and further inventories for Baird's sparrows should be conducted.