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CORRELATION OF RED-SHOULDERED HAWK ABUNDANCE AND MACROHABITAT CHARACTERISTICS IN SOUTHERN OHIO
Citation:
Dykstra, C. R., F B. Daniel, J. L. Hays, AND M. M. Simon. CORRELATION OF RED-SHOULDERED HAWK ABUNDANCE AND MACROHABITAT CHARACTERISTICS IN SOUTHERN OHIO. CONDOR 103(3):652-656, (2001).
Impact/Purpose:
This project has three overall goals: 1) To develop efficacious methods for quantitative assessment of riparian resources at a both local and watershed scales; 2) to examine land use elements, at various scales as regulators of both water quality and biological integrity in freshwater streams, and 3) to elucidate the potential of riparian corridors to ameliorate various stressor impacts from the surrounding catchment.
Approach
-FY00 Activities The field sampling conducted in the first year will be repeated for all of the sub-watershed sites in the second year. Using the sub-watershed boundaries determined via the hydrologic models the landscape metrics for each sub-watershed will be developed. Likewise the high resolution land cover data for the riparian corridors will be developed from the digitized aerial photography.
-FY01 Activities The field sampling conducted in the years one and two will be repeated for all of the sub-watershed sites in year three. The field data from all three years will be combined to develop the indices of water quality and biotic integrity for the sub-watersheds. The stream quality and land cover data from the watershed catchment area and the riparian corridor will be correlated using a series of step-wise, multistage, linear regression models. Individual features of stream quality will be related to various riparian land cover parameters and other land use elements in the watershed as a whole. Statistical analysis will be completed.
-FY02 Activities Final reports and manuscripts for submission to the peer reviewed scientific literature will be prepared.
Description:
We measured an index of Red-shouldered Hawk (Buteo lineatus) abundance along streams in southern Ohio and related differences in abundance index to landscape scale habitat characteristics within the surveyed areas. Fifteen study sites, each a 5.8-km reach of permanent stream, were surveyed four times using broadcasts of Red-shouldered Hawk calls and Red-tailed Hawk (Buteo jamaicensis) calls. We determined the landcover types in a corridor surrounding each surveyed area using a GIS landcover data grid, and counted the number of small ponds within each corridor. We calculated hawk response rate for each species as the mean number of visual or aural detections per survey. Red-shouldered Hawk response rate was inversely correlated to Red-tailed Hawk response rate (r = -0.52, P < 0.04), and was positively correlated to the number of small ponds within each stream corridor (r = 0.77, P < 0.01), suggesting that the number of small ponds was important factor associated with Red-shouldered Hawk abundance.