Sex Determination of Eastern Red-tailed Hawks (Buteo jamaicensis borealis) Using Morphological Measurements
Major
Biology
Submission Type
Poster
Area of Study or Work
Biology
Expected Graduation Date
2022
Location
CNS Atrium, Easel 12
Start Date
4-9-2022 11:15 AM
End Date
4-4-2022 12:30 PM
Disciplines
Biology
Abstract
Red-tailed hawks (Buteo jamaicensis), which are one of the most common large diurnal raptors found throughout North America, are often seen soaring overhead or perched on utility poles. While there are twelve recognized subspecies, the Eastern Red-tailed Hawk (B.j. borealis) is the only one that breeds and winters in Illinois. Although female red-tails are typically larger than males, there is no reliable, non-invasive technique to assess the sex of individuals in-hand. Current methods of sex determination require plucking feathers or drawing blood for DNA analysis. Donohue and Dufty (2006) used discriminant function analysis of measurements of captured Western Red-tailed-Hawks (B. j calurus) to successfully determine the sex of both adults (98% accuracy) and juveniles (97% accuracy). However, these measurements have not been tested to determine the sex of the eastern subspecies, which is the focus of this study. We used morphometrics (wing chord, mass, hallux (hind talon) length, culmen (beak) size, and tail feather length) described by Donohue and Dufty (2006) to determine the sex of 29 frozen B.j. borealis in the Illinois State University Museum. The hawks were sexed via necropsy. Our results yielded 86% accuracy for adults and 93% accuracy for juveniles. These analyses will be performed on live-trapped birds, with sex determined by DNA extracted from breast feathers. This is the first study to establish reliable, in-hand sex determination for eastern Red-tailed Hawks.
Sex Determination of Eastern Red-tailed Hawks (Buteo jamaicensis borealis) Using Morphological Measurements
CNS Atrium, Easel 12
Red-tailed hawks (Buteo jamaicensis), which are one of the most common large diurnal raptors found throughout North America, are often seen soaring overhead or perched on utility poles. While there are twelve recognized subspecies, the Eastern Red-tailed Hawk (B.j. borealis) is the only one that breeds and winters in Illinois. Although female red-tails are typically larger than males, there is no reliable, non-invasive technique to assess the sex of individuals in-hand. Current methods of sex determination require plucking feathers or drawing blood for DNA analysis. Donohue and Dufty (2006) used discriminant function analysis of measurements of captured Western Red-tailed-Hawks (B. j calurus) to successfully determine the sex of both adults (98% accuracy) and juveniles (97% accuracy). However, these measurements have not been tested to determine the sex of the eastern subspecies, which is the focus of this study. We used morphometrics (wing chord, mass, hallux (hind talon) length, culmen (beak) size, and tail feather length) described by Donohue and Dufty (2006) to determine the sex of 29 frozen B.j. borealis in the Illinois State University Museum. The hawks were sexed via necropsy. Our results yielded 86% accuracy for adults and 93% accuracy for juveniles. These analyses will be performed on live-trapped birds, with sex determined by DNA extracted from breast feathers. This is the first study to establish reliable, in-hand sex determination for eastern Red-tailed Hawks.