Determining the Distribution 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 11
Start Date
4-15-2023 9:00 AM
End Date
4-15-2023 10:15 AM
Abstract
Determining the Distribution of Wintering Red-tailed Hawk Subspecies in Illinois
Steven Burkett1, Meredith Fraker2, Miles Keeton1, Eleanor Blew2
Given Harper1,2*
Environmental Studies Program1 and Biology Department2, Illinois Wesleyan University
Red-tail hawks (Buteo jamaicensis; RTHAs) are one of the most common large diurnal raptors found throughout North America. Four of 14 recognized subspecies winter in Illinois: Buteo jamaicensis borealis, the predominant subspecies found year-round in Illinois and eastern North America; B. j. calurus (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, a putative subspecies, breeds from New England to southeast Alaska. Few systematic efforts have been conducted to determine the winter distribution of RTHA subspecies in Illinois. Wintering RTHAs 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 photo analyses (n = 747) indicate that B. j. borealis comprised 88.49% of sightings, followed by B. j. calurus (4.82%), B. j. abieticola (3.61%), B. j. harlani (1.34%) and B. j. kriderii (0.94%). 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. harlani only extended into the southwestern and western edges of Illinois. In contrast, our data indicate both subspecies winter northeast of Wheeler’s demarcation, extending into central and northern Illinois. The distribution of B. j. kriderii expanded 97.63 km east and 44.64 km north of Wheeler’s distribution, and 90.18 km east and 70.93 km north for B.j. harlani. B. j. abieticola was found throughout the northeastern and central regions of the state. These data can aid in understanding how climate change may alter the future winter distribution pattern of RTHA subspecies in the midwestern U.S.
Determining the Distribution of Wintering Red-tailed Hawk Subspecies in Illinois
CNS Atrium, Easel 11
Determining the Distribution of Wintering Red-tailed Hawk Subspecies in Illinois
Steven Burkett1, Meredith Fraker2, Miles Keeton1, Eleanor Blew2
Given Harper1,2*
Environmental Studies Program1 and Biology Department2, Illinois Wesleyan University
Red-tail hawks (Buteo jamaicensis; RTHAs) are one of the most common large diurnal raptors found throughout North America. Four of 14 recognized subspecies winter in Illinois: Buteo jamaicensis borealis, the predominant subspecies found year-round in Illinois and eastern North America; B. j. calurus (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, a putative subspecies, breeds from New England to southeast Alaska. Few systematic efforts have been conducted to determine the winter distribution of RTHA subspecies in Illinois. Wintering RTHAs 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 photo analyses (n = 747) indicate that B. j. borealis comprised 88.49% of sightings, followed by B. j. calurus (4.82%), B. j. abieticola (3.61%), B. j. harlani (1.34%) and B. j. kriderii (0.94%). 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. harlani only extended into the southwestern and western edges of Illinois. In contrast, our data indicate both subspecies winter northeast of Wheeler’s demarcation, extending into central and northern Illinois. The distribution of B. j. kriderii expanded 97.63 km east and 44.64 km north of Wheeler’s distribution, and 90.18 km east and 70.93 km north for B.j. harlani. B. j. abieticola was found throughout the northeastern and central regions of the state. These data can aid in understanding how climate change may alter the future winter distribution pattern of RTHA subspecies in the midwestern U.S.