Authors

Rachael M. Pruitt '17, Gettysburg College

Advisor: Dr. Andy Wilson, Gettysburg College

Document Type

Student Research Paper

Date of Creation

Spring 2017

Department

Environmental Studies

Abstract

The Broad-winged Hawk (BWHA), Buteo platypterus, a small, secretive hawk with distinguishing broad black tail bands, breeds in northeastern North America. The hawks nest in deciduous or mixed forest, often near water, and close to clearings or forest edges. Land conversion and fragmentation alters the landscape and reduces the area of contiguous forest used by BWHA. This study seeks to determine the habitat metrics that may be influencing the apparent breeding range declines of the BWHA at the landscape scale. Landscape characteristics and BWHA presence data from 18,684 Breeding Bird Atlas blocks (each about 25km2) from Ohio, West Virginia, Maryland, Pennsylvania, and New York for two atlas period (1st Atlas: 1980s, 2nd Atlas: 2000s) were analyzed. Logistic regression models revealed block level declines in BWHA presence that were associated with increases in urban, barren, wetland and agricultural land cover. These trends were especially prevalent in low-elevation areas around the region’s largest cities: New York, Philadelphia, Baltimore and Washington DC. Alternatively, an increase in predicted presence was associated with increases in core and edge forest, specifically in regions of New York. Availability of forested habitat with large areas of core forest at higher latitudes and elevations appear to be influential in the breeding habitat selection of BWHA and may be suggestive of a climate change influence. Additional research on the relative influence of each of the metrics and the impacts that the range decline may have on BWHA populations is warranted

Comments

Written as an Honors Project in Environmental Science.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

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