Sex Determination of Eastern Red-tailed Hawks (Buteo jamaicensis borealis) Using Morphological Measurements
Major
Environmental Studies
Submission Type
Poster
Area of Study or Work
Biology, Environmental Studies
Expected Graduation Date
2023
Location
CNS Atrium, Easel 32
Start Date
4-15-2023 10:30 AM
End Date
4-15-2023 11:45 AM
Abstract
Sex Determination of Eastern Red-tailed Hawks (Buteo jamaicensis borealis) Using Morphological Measurements
Steven Burkett1, Meredith Fraker2, Miles Keeton1, Eleanor Blew2
Richard Alvey2 *, and Given Harper1,2 *
Environmental Studies Program 1 and Biology Department 2 ,
Illinois Wesleyan University
Red-tail hawks (Buteo jamaicensis; RTHAs) are one of the most common large diurnal raptors found throughout North America. While there are 14 recognized subspecies, the Eastern RTHA (B. j. borealis) is the only one that breeds and winters in Illinois. Female Eastern RTHAs are typically larger than males, but there is no reliable, non-invasive technique to sex individuals in-hand. Donohue and Dufty (2006) used discriminant function analysis of measurements of Western Red-tailed-Hawks (B. j. calurus) to successfully determine the sex of adults (98% accurate) and juveniles (97% accurate). Washburn et al. (2022) recently developed equations to predict the sex of B. j. borealis, which were 87.5% accurate for adults and 86% for juveniles. However, measurements for the western subspecies have not been tested to determine the sex of the eastern subspecies, which is the purpose of this study. We used morphometrics (wing chord, mass, hallux (hind talon) length, culmen (beak) size, and tail feather length) and equations described in both papers to determine the sex of 58 live-trapped and frozen B. j. borealis from the Illinois State University Museum. Hawks live-trapped during the winters of 2020 and 2021 were sexed using DNA extracted from feathers, while frozen hawks were sexed via necropsy. Our results using the Washburn et al. (2022) equations were 75% accurate in determining the sex of adults, and 88% for juveniles. In contrast, results using modified Donohue and Dufty (2006) equations yielded 90.6% accuracy for adults and 92.3% for juveniles. We are currently live- trapping additional hawks to increase our sample size to statistically test the efficacy of both equations.
Sex Determination of Eastern Red-tailed Hawks (Buteo jamaicensis borealis) Using Morphological Measurements
CNS Atrium, Easel 32
Sex Determination of Eastern Red-tailed Hawks (Buteo jamaicensis borealis) Using Morphological Measurements
Steven Burkett1, Meredith Fraker2, Miles Keeton1, Eleanor Blew2
Richard Alvey2 *, and Given Harper1,2 *
Environmental Studies Program 1 and Biology Department 2 ,
Illinois Wesleyan University
Red-tail hawks (Buteo jamaicensis; RTHAs) are one of the most common large diurnal raptors found throughout North America. While there are 14 recognized subspecies, the Eastern RTHA (B. j. borealis) is the only one that breeds and winters in Illinois. Female Eastern RTHAs are typically larger than males, but there is no reliable, non-invasive technique to sex individuals in-hand. Donohue and Dufty (2006) used discriminant function analysis of measurements of Western Red-tailed-Hawks (B. j. calurus) to successfully determine the sex of adults (98% accurate) and juveniles (97% accurate). Washburn et al. (2022) recently developed equations to predict the sex of B. j. borealis, which were 87.5% accurate for adults and 86% for juveniles. However, measurements for the western subspecies have not been tested to determine the sex of the eastern subspecies, which is the purpose of this study. We used morphometrics (wing chord, mass, hallux (hind talon) length, culmen (beak) size, and tail feather length) and equations described in both papers to determine the sex of 58 live-trapped and frozen B. j. borealis from the Illinois State University Museum. Hawks live-trapped during the winters of 2020 and 2021 were sexed using DNA extracted from feathers, while frozen hawks were sexed via necropsy. Our results using the Washburn et al. (2022) equations were 75% accurate in determining the sex of adults, and 88% for juveniles. In contrast, results using modified Donohue and Dufty (2006) equations yielded 90.6% accuracy for adults and 92.3% for juveniles. We are currently live- trapping additional hawks to increase our sample size to statistically test the efficacy of both equations.