Rough-legged Buzzard

This fairly large raptorial species is 46–68 cm (18–27 in) with wingspan ranging from 120 to 153 cm (47 to 60 in). Individuals can weigh from 600 to 1,660 g (1.32 to 3.66 lb) with females typically being larger and heavier than males. Weights appear to increase from summer to winter in adults, going from an average of 822 to 1,027 g (1.812 to 2.264 lb) in males and from 1,080 to 1,278 g (2.381 to 2.818 lb) in females. Among the members of the genus Buteo, it is sixth heaviest, the fifth longest, and the fourth longest winged. Among standard measurements in adults, the wing chord is 37.2–48. Voice: Adult rough-legged buzzards will give alarm calls when intruders approach a nesting site. It is described as a downward slurring whistle, sounding like kiu wiyuk or a lengthy descending kee-eer similar to that of the red-tailed hawk. This cry is given in flight or from a perch every 15–30 seconds. During courtship, both sexes have been recorded to give a whistling sound that changes to a hiss.