Preserve Selection and Design Considerations: Nest success may be higher in larger, contiguous grassland areas. Prairie management to maximize nest productivity should provide large (> 130 ha), regularly burned prairies with no nearby wooded edges (Johnson and Temple 1990). In South Dakota, abundance was greater in habitat patches within larger areas dominated by grassland; patch size was not as important as its landscape context (Bakker et al. 2002). In Minnesota tallgrass prairie, brood parasitism by Brown-headed Cowbirds (MOLOTHRUS ATER) and nest depredation rates decreased as distance from wooded edges increased, and nest depredation rates were lower on large (130-486 ha) than on small (16-32 ha) grasslands (Johnson and Temple 1990). Nests are frequently parasitized by Brown-headed Cowbirds (Peabody 1899, Fox 1961, Friedmann and Kiff 1985, Stewart 1975, Knapton 1978, Buech 1982), and parasitism almost always results in lower sparrow productivity (Fox 1961, Salt 1966, Root 1968, Knapton 1978, Buech 1982).
Management Requirements: BURNING: In North Dakota, areas left unburned > 80 yr, and areas ungrazed > 11 yr had higher densities than recently burned and grazed areas (Madden 1996, Johnson 1997). In mesic mixed-grass prairie, conduct prescribed burns at moderate to long (8-10 yr) fire return intervals (Madden 1996, Johnson 1997). Shorter fire return intervals can frequently reduce woody vegetation and litter, resulting in decreased sparrow density or avoidance of burned habitats altogether (Huber and Steuter 1984, Pylypec 1991, Berkey et al. 1993). Intense fires which burn off shrubs have a negative short-term effect (Halvorsen and Anderson 1983, Huber and Steuter 1984, Madden 1996, Johnson 1997). In Saskatchewan, breeding densities in burned areas three years post-fire were one-third the densities in unburned areas (Pylypec 1991). In South Dakota, avoided burned areas, preferring denser vegetation in a lightly-grazed, unburned area (Martin 1967, Huber and Steuter 1984). Madden (1996) found that sparrows in North Dakota mixed-grass responded negatively to fire and were most abundant in areas unburned in greater than 80 years. Numbers increased with the number of years since the most recent burn, suggesting that moderate and long fire return intervals would be most beneficial (Madden 1996, Johnson 1997). Burned areas which retained shrubs were used immediately after burning (Johnson 1997). In Wisconsin, however, burning of residual cover caused a 94% decline in density after spring burning, even though no differences in shrub density were noted between burned and unburned areas (Halvorsen and Anderson 1983).
AGRICULTURE: Idle grasslands support high breeding densities (Renken 1983, Messmer 1990, Hartley 1994, Madden 1996). In southcentral North Dakota, use of idle areas decreased after mowing and as western snowberry cover decreased (Messmer 1990). In southern and southcentral North Dakota DNC fields, sparrows used tall, dense grass and forb cover in shrubless areas (Renken 1983, Renken and Dinsmore 1987, Johnson and Schwartz 1993b). In Saskatchewan, occurred with almost equal frequency in idle, native grassland as in DNC (Hartley 1994). However, in North Dakota, densities were significantly higher in idle grassland than DNC or grazed areas (Renken 1983). In Saskatchewan, preferred idle grasslands to haylands mowed either annually or periodically (about every 3-8 yr) (Dale et al. 1997).
Although sparrows tend to avoid haylands in North Dakota, mowing can be used to halt long-term succession (Kantrud 1981, Berkey et al. 1993). Will utilize hayland, but it does not appear to be preferred habitat (Kantrud 1981, Anstey et al. 1995, Dale et al. 1997, Davis et al. in press). Cropland is also rarely used for nesting (Salt 1966, Johnson and Schwartz 1993a, Knapton 1994, Anstey et al. 1995), but may provide sparser, shorter vegetation suitable for foraging (Dale 1983, Knapton 1994). In Saskatchewan, were frequently detected in wheat fields (Hartley 1994), and in Alberta, Salt (1966) often observed them in cultivated fields after young fledged. Shrubs retained along field edges are often used for nesting (Owens and Myres 1973, Dale 1983). In Alberta, were detected more frequently along a roadside route through cultivated land than along a route with more native grassland (Owens and Myres 1973). In Saskatchewan, were more frequent in native pasture than tame pasture with less shrub cover (Anstey et al. 1995). In North Dakota, were common in a variety of treatment types, including short-duration, season-long, twice-over rotation, and idle, but were consistently most abundant in areas with more western snowberry cover (Messmer 1990).
GRAZING: Sparrows exhibit ambiguous responses to grazing, but appear to be affected more by shrub coverage than by grazing regime (Bock et al. 1993). In North Dakota, were common in variety of grazing treatments, including short-duration, seasonlong, idle, and twice-over rotation, but were most abundant in areas with greater shrub cover (Messmer 1990). Light to moderate grazing on mixed-grass prairie may benefit sparrows by providing foraging areas of sparser cover, particularly if shrub cover is retained (Owens and Myres 1973, Kantrud 1981, Kantrud and Kologiski 1982, Dale 1983, Huber and Steuter 1984, Arnold and Higgins 1986, Messmer 1990, Bock et al. 1993, Knapton 1994, Anstey et al. 1995, Saab et al. 1995). Avoid heavy grazing which removes ground cover (Kantrud 1981, Kantrud and Kologiski 1982, Dale 1983). In Alberta, heavy grazing may be acceptable if shrubs remain (Owens and Myres 1973).
Lightly to moderately grazed grasslands are often used, but shrub cover may be a more important factor in determining habitat suitability than grazing regime (Owens and Myres 1973, Kantrud 1981, Kantrud and Kologiski 1982, Dale 1984, Bock et al. 1993, Anstey et al. 1995, Saab et al. 1995). Heavy grazing is detrimental, possibly because ground and/or shrub cover are reduced (Kantrud 1981, Kantrud and Kologiski 1982, Dale 1983).
