Science Inventory

BEHAVIOR AND PREY OF NESTING RED-SHOULDERED HAWKS IN SOUTHWESTERN OHIO

Citation:

Dykstra, C. R., J. L. Hays, M. M. Simon, AND F B. Daniel. BEHAVIOR AND PREY OF NESTING RED-SHOULDERED HAWKS IN SOUTHWESTERN OHIO. JOURNAL OF RAPTOR RESEARCH 37(3):237-246, (2003).

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 used direct observations to quantify prey types, prey delivery rate, and adult and nestling behavior at nests of Red-shouldered Hawks (Buteo lineatus) in suburban southwestern Ohio. Twenty-one nests were observed for a total of 256 hr in 1997-2001. Small mammals made up the largest percentage of the identified prey (31.5%), followed by reptiles (22.7%), invertebrates (18.8%), amphibians (17.7%), birds (6.9%) and fish (2.5%). Season-long prey delivery rate averaged 3.5 +/- 0.6 prey items delivered per 4-hr observation period, or 116 +/- 19 g biomass delivered per 4-hr observation period. Weekly prey delivery rate showed no correlation with the age of the nestlings (p > 0.05). Adult attendance at the nest and time adults spent brooding nestlings both were negatively correlated with nestling age (P < 0.05). Time adults spent feeding nestlings was negatively correlated with nestling age (r2 - 0.92, P - 0.002), while time nestlings spent feeding themselves was positively correlated with nestling age (r2 - 0.92, P = 0.003). These data may serve as a baseline for assessing prey delivery rates and behavior of populations of Red-shouldered Hawks throughout the lower Midwest.

Record Details:

Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Product Published Date: 12/01/2003
Record Last Revised: 11/16/2005
OMB Category: Other
Record ID: 81314

Organization:

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF RESEARCH AND DEVELOPMENT

NATIONAL EXPOSURE RESEARCH LABORATORY

ECOLOGICAL EXPOSURE RESEARCH DIVISION

ENVIRONMENTAL CONTAMINANT CHARACTERIZATION BRANCH