In March 1999, we selected starting points for each point count transect. In June 1999, we completed laying out the remainder of each transect. To mark each transect, we used a measuring tape and a compass to walk a straight course for 250-300 m from the chosen starting point. At the end point, the map was checked to verify that the location was correct by referencing recognizable landmarks such as fence lines, road intersections, and topography. We then marked each point with a wooden stake and plastic tag on which the transect name and point number were written. A non-differentially corrected GPS fix was obtained for each point to facilitate relocating the points even if the stakes are removed.
Birds Point Counts Avian point counts were conducted after the methods of Reynolds et al. (1980), Freemark and Rodgers (1995), Ralph et al. (1995), and Rotenberry and Knick. (1995). The objective was to record all birds observed visually and aurally from a stationary position during specified hours. Each sample point was visited once during the first four hours of daylight, and only during conditions acceptable to auditory and visual detection. Days with rain or high wind were not sampled. Upon arrival at each point, a minimum of 3 minutes elapsed for acclimation, followed by a 10-minute observation period. This lengthy observation period accounted for greater observer effect in open habitats (Savard and Hooper, 1995). Observations were recorded on field data sheets by species and general activity, i.e., foraging, flybys, calling, etc., and classed as visual or auditory. Bearing and range were recorded to allow possible incorporation of variable circular plot methodology for preliminary density estimates (Reynolds et al. 1980). Field data forms also included point identification number, GPS coordinates, start time for each count station, and weather observations. In addition, non-avian observations were recorded as incidentals on a separate section of the data form. Breeding season point counts were conducted in mid-June at 48 locations. Point counts were repeated in February at 36 locations to characterize wintering species diversity and abundance. The winter count was not time constrained to the first four hours of daylight as was the breeding season count, but was restricted to periods when observations were not compromised by the weather. Lone individuals conducted point counts. Observers were experienced in field identification of upland species by sight and sound, and referred to field guides and tape-recorded bird songs for unknown species. In addition, avian observations made prior to the breeding season point counts (such as during establishment of transects and marking of survey points) familiarized the observers with the species present.