Determining the Distribution and Abundance of Wintering Red-tailed Hawk Subspecies in Illinois
Major
Environmental Studies
Submission Type
Poster
Area of Study or Work
Biology, Environmental Studies
Expected Graduation Date
2023
Location
CNS Atrium, Easel 27
Start Date
4-9-2022 8:30 AM
End Date
4-9-2022 9:45 AM
Abstract
Determining the Distribution and Abundance of Wintering Red-tailed Hawk Subspecies in Illinois
Steven Burkett2, Rebekah Harden1, Miles Keeton2, Meredith Fraker1
and R. Given Harper*
Biology Department1 and Environmental Studies2 Program, Illinois Wesleyan University
Red-tailed Hawks (RTHA), which are one of the most common raptorial birds in North America, are often seen soaring or hunting from trees and the tops of utility poles. Five of twelve recognized subspecies winter in Illinois: Buteo jamaicensis borealis, the predominant subspecies found year-round in Illinois and eastern North America; B. j. calarus (breeds in western North America); B. j. kriderii (breeds in northern Great Plains and western Canada); B. j. harlani (breeds in Alaska); B. j. abieticola (breeds from New England to southeast Alaska; under consideration as a distinct subspecies). Few systematic efforts have been conducted to determine the winter distribution and abundance of RTHA subspecies within the state. Wintering RTHAs in Illinois were identified via analyses of photos of live-trapped hawks, photo submissions to eBird (a national repository of documented bird sightings in the U.S.), documentation in Vert Net (listing of RTHA study skins in museum collections), photos from private individuals, and winter raptor surveys. Preliminary analyses of photos (n = 390) indicate that B. j. borealis comprised 90.3% of sightings, followed by B. j. abieticola (3.5%), B. j. calurus (2.7%), B. j. harlani (2.7%) and B. j. kriderii (0.8%). Our analysis corroborates Wheeler’s (2018) distribution map for B. j. calurus and B.j. borealis, which winter throughout Illinois. However, the Wheeler distribution maps of wintering B. j. kriderii and B. j. harlanii only extended into the southwestern edge of Illinois. In contrast, our data indicate they winter northeast of Wheeler’s demarcation, extending into central and northern Illinois. These data can inform future conservation efforts and aid in understanding how climate change may alter the winter distribution pattern of RTHA subspecies in the midwestern U.S.
Determining the Distribution and Abundance of Wintering Red-tailed Hawk Subspecies in Illinois
CNS Atrium, Easel 27
Determining the Distribution and Abundance of Wintering Red-tailed Hawk Subspecies in Illinois
Steven Burkett2, Rebekah Harden1, Miles Keeton2, Meredith Fraker1
and R. Given Harper*
Biology Department1 and Environmental Studies2 Program, Illinois Wesleyan University
Red-tailed Hawks (RTHA), which are one of the most common raptorial birds in North America, are often seen soaring or hunting from trees and the tops of utility poles. Five of twelve recognized subspecies winter in Illinois: Buteo jamaicensis borealis, the predominant subspecies found year-round in Illinois and eastern North America; B. j. calarus (breeds in western North America); B. j. kriderii (breeds in northern Great Plains and western Canada); B. j. harlani (breeds in Alaska); B. j. abieticola (breeds from New England to southeast Alaska; under consideration as a distinct subspecies). Few systematic efforts have been conducted to determine the winter distribution and abundance of RTHA subspecies within the state. Wintering RTHAs in Illinois were identified via analyses of photos of live-trapped hawks, photo submissions to eBird (a national repository of documented bird sightings in the U.S.), documentation in Vert Net (listing of RTHA study skins in museum collections), photos from private individuals, and winter raptor surveys. Preliminary analyses of photos (n = 390) indicate that B. j. borealis comprised 90.3% of sightings, followed by B. j. abieticola (3.5%), B. j. calurus (2.7%), B. j. harlani (2.7%) and B. j. kriderii (0.8%). Our analysis corroborates Wheeler’s (2018) distribution map for B. j. calurus and B.j. borealis, which winter throughout Illinois. However, the Wheeler distribution maps of wintering B. j. kriderii and B. j. harlanii only extended into the southwestern edge of Illinois. In contrast, our data indicate they winter northeast of Wheeler’s demarcation, extending into central and northern Illinois. These data can inform future conservation efforts and aid in understanding how climate change may alter the winter distribution pattern of RTHA subspecies in the midwestern U.S.