Adult Rough-legged Hawks (Buteo lagopus) are depicted and described in bird guides and handbooks as sexually dimorphic in plumage, although several authorities have reported that the sexes overlap in plumage. We examined photographs of 106 adult and Basic III Rough-legged Hawks that had been captured and measured, and more than 200 museum specimens to assess sexual dimorphism in five plumage characters and in wing chords. On the basis of museum specimens with gonad information on their labels, the sexes are distinguishable by wing chord, which is >420 mm in females and <418 in males. Most light-morph adults have the plumage of their sex as described in field guides and handbooks, but a few appear like the other sex. Gray barring on the back feathers and barring on the flanks (present in males, absent in females) are the best plumage indicators of the sex of birds in Definitive and Basic III plumages. Tail pattern was the most shared character and is not a reliable indicator of adults' sex.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.