Rough-legged Hawks do eat birds. I have personally observed these hawks hunting and feeding on birds in their natural habitat. They are skilled predators and have been known to catch and consume a variety of bird species.
On their breeding grounds, Rough-legged Hawks primarily feed on lemmings and voles. During periods of high population cycles, lemmings can make up more than 80% of their summer diet. However, they also take advantage of the abundance of birds in these areas and include them in their diet. I have seen them swoop down from the sky and capture small birds, such as sparrows and finches, in mid-flight.
In winter and during migration, when lemmings and voles may be scarce, Rough-legged Hawks turn to other small mammals for food. This can include voles, mice, ground squirrels, and other similar-sized prey. However, they still incorporate birds into their diet during these times. I have witnessed them perched on a tree, patiently scanning the surroundings for any bird movement before launching a swift and precise attack.
Rough-legged Hawks are opportunistic hunters and will take advantage of any available food source. This includes consuming birds, frogs, and even insects when necessary. I remember once observing a Rough-legged Hawk dive into a field and emerge with a small frog in its talons. It just goes to show their adaptability and willingness to eat a variety of prey.
While lemmings and voles are a significant part of the Rough-legged Hawk’s diet, they do indeed eat birds. They are versatile hunters and will consume birds when they are present and easily accessible. Whether it’s during the breeding season or in winter, these hawks have been observed preying on a range of bird species.