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Assemblages Of Breeding Birds As Indicators Of Grassland Condition, Sharon Freshman Browder, Douglas H. Johnson, I. J. Ball
Assemblages Of Breeding Birds As Indicators Of Grassland Condition, Sharon Freshman Browder, Douglas H. Johnson, I. J. Ball
USGS Northern Prairie Wildlife Research Center
We developed a measure of biological integrity for grasslands (GI) based on the most influential habitat types in the Prairie Pothole Region of North Dakota. GI is based on proportions of habitat types and the relationships of these habitat types to breeding birds. Habitat types were identified by digital aerial photography, verified on the ground, and quantified using GIS. We then developed an index to GI based on the presence or abundance of breeding bird species. Species abundance data were obtained from 3 min roadside point counts at 889 points in 44, 4050 ha study plots over a 2-year period. …
Dramatic Increase Of Le Conte's Sparrow In Conservation Reserve Program Fields In The Northern Great Plains, Lawrence D. Igl, Douglas H. Johnson
Dramatic Increase Of Le Conte's Sparrow In Conservation Reserve Program Fields In The Northern Great Plains, Lawrence D. Igl, Douglas H. Johnson
USGS Northern Prairie Wildlife Research Center
During a continuing investigation in the northern Great Plains, we documented substantial increases of the Le Conte's Sparrow (Ammodramus Leconteii) in Conservation Reserve Program (CRP) fields in 1994 compared with 1990-93. The most dramatic increases occurred in Eddy County, North Dakota, and Sheridan County, Montana. The changes in habitat associated with the drought from 1989 to early 1993 and above-normal precipitation from mid-1993 through mid-1994 likely produced favorable breeding conditions for this species in CRP fields in 1994.