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Improving Prairie Pond Counts with Aerial Video
and Global Positioning Systems

Study Area


We conducted the study in southern Saskatchewan in May 1992 along portions of 9 transects used in the BGS (Fig. 1). We subjectively selected the 9 transects as representing prairie and parkland habitats in the Prairie Pothole Region after consultation with U.S. Fish and Wildlife Service and Canadian Wildlife Service biologists and because their proximal distribution facilitated logistics. At each of 8 transects, we studied 3 contiguous 29-km transect segments that included 1 air-ground segment. At the ninth (transect 17), we studied 6 contiguous segments that included 4 air-ground segments.

gif -- Map of Transect Segments

Figure 1. Relationship of 12 air-ground segments to 30 29-km transect segments from 9 transects of the Aerial Waterfowl Breeding Ground Population and Habitat Surveys in southern Saskatchewan, May 1992. The center line of the transect is shown. Transect segments are numbered and delimited by lines perpendicular to the transect center line. Air-ground segments are named below the triangles delimiting their extent.

Air-ground segments were of primary interest because the ground BGS provided detailed information for individual ponds that could be used to estimate accuracy of pond detection from video imagery. We studied transect segments adjacent to air-ground segments to provide a larger sample size for a regression between pond counts from the video interpretation and from aerial BGS and to estimate time required for video interpretation. We determined land cover and use composition of air-ground segments from 1:12,000 scale color infrared aerial photographs acquired in May 1991 and 1992. Grain farming was the primary land use along all air-ground segments. Grassland was most abundant on the Shamrock, Tichfield, Pleasantdale, Earl Grey and Hanley air-ground segments. Aspen parkland vegetation was most abundant on the Pleasantdale, Hendon, Nut Mountain, Earl Grey, and Hanley air-ground segments. Total number of ponds in May 1992 in southern Saskatchewan was 18% below the long-term average (U.S. Fish and Wildl. Serv. 1992).


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