We used flushing transect-surveys to sample species that were relatively easy to identify when flushed: northern harriers (Circus cyaneus); horned larks (Eremophila alpestris); Sprague's pipits (Anthus spragueii); vesper sparrows (Pooecetes gramineus); eastern and western meadowlarks (Sturnella magna and S.
Finally, for northern harriers, we included an additional candidate-model with total number of sparrows as a covariate.
For northern harriers (raptor), abundance was best (lowest [QAIC.
With regard to (a), while gulls and osprey are absent in the meadow habitat, sandhill cranes and northern harriers are common in the meadows but not along the lakeshore.
Foraging behavior of Northern Harriers wintering in southereastern salt and freshwater marshes.
Using a variety of nets, DEC staff safely capture short-eared owls and northern harriers, determine their age and sex if possible, and gather other biological information.
This land now protects a key roosting and foraging area for both short-eared owls and northern harriers, as well as habitat for other at-risk grassland species.
Greater prairie-chicken leks are occasionally used for decades (Horak, 1984) and northern harrier nests at this sate are often located within 75 m of nests from the previous year (J.
The occurrence of northern harriers was not related to tract area, primarily due to their presence in 3 y on a 7-ha grassland (Table 1).
Minimum area requirements were 55 ha for northern harriers and 65 ha for greater prairie-chickens and upland sandpipers.
Nesting northern harriers (Circus cyaneus) have been reported on reclaimed surface mines in Ohio (Peterjohn and Rice 1991), Pennsylvania (Rohrbaugh, Jr.
Both northern harriers and short-eared owls require relatively large, contiguous grassland tracks for hunting during the winter months (Holt and Leasure 1993, MacWhirter and Bildstein 1996, Walk and Warner 1999, Wilson and others 2010), and both have undergone population declines during the past 30 to 40 years in much of their North American ranges largely as the result of habitat loss (Robbins and others 1986, Tate 1986, Holt and Leasure 1993, MacWhirter and Bildstein 1996, Sauer and others 2008).
001, df = 27) from January through April, while the number of northern harriers, a predominately winter resident, increased slightly, but not significantly, during the study (F = 0.
And while it is important to short-eared owls, it also provides important habitat for almost a dozen other threatened and at-risk grassland-dependent birds, including northern harriers, upland sandpipers, American kestrels, eastern meadowlarks and grasshopper sparrows.
Short-eared owls and state-threatened northern harriers need large, grassy open areas for several reasons.