A visitor from the Arctic
That big, lemming-loving Arctic bird has finally been sighted again on Cape Cod. Just in from some tundra breeding ground in northern Canada or Alaska, this fierce and seldom-seen raptor of big, open areas is getting local birders excited for winter, with sightings of different birds in Dennis and Orleans. I am of course referring to Rough-legged Hawks. What did you think I meant?
Ah, I see the confusion. Yes, both Snowy Owls and Rough-legged Hawks nest on rolling Arctic tundra and feed primarily on lemmings, and both are sought-after and unpredictable species here in winter. But a Rough-legged Hawk is much harder to find on the Cape than a Snowy Owl – they appear in fewer years, in fewer places, and in smaller numbers than their owly counterparts. I can only recall two distant sightings I’ve had on the Cape over the last 20 years. So birders are excited that there may be at least two around right now.
Rough-legged Hawks are buteos, big, soaring hawks closely related to Red-tailed Hawks. So how do you know you are looking at the rare Arctic visitor and not the ho-hum hawk? Rough-legs have a dizzying array of plumages depending on age and sex, but they should always look longer-winged than a Red-tail with more languid flight. We mostly see the light morphs, which have distinctive dark squares at the bend of the wing and a dark band at the end of the tail. Less common dark morphs will be all chocolate brown with whitish flight feathers.
Rough-legs aren’t as heavy as red-tails, which may explain their tendency to perch on tiny little twigs smaller than what a Red-tail would normally use – it’s a great way to pick them out when driving around big agricultural areas in southern Canada or Northern New England in winter. They also hover more than red-tails, but don’t get fooled by a Northern Harrier, a more common hawk of winter marshes with similar proportions and a propensity for hovering. I never said hawk ID was easy. As the name hints, Rough-legged Hawks have legs feathered all the way to the toes, which is more typical of eagles than hawks. But given where they live, the weather would be pretty rough on their legs without those feathers.
In Massachusetts, I can only think of three places where Rough-legs are reliably seen every winter – Plum Island in Newburyport, the huge Cumberland Farms field complex in Halifax and Middleboro, and Mass Audubon’s Daniel Webster sanctuary in Marshfield – all are big, open wetland/grassland complexes teeming with rodents. Around here it’s a bad bet, but if you’re feeling lucky, look for them in the biggest marshes we have – the Nauset Beach marshes and the Great Marsh of Barnstable. However, two different birders saw them this week in the smaller Chase Garden Creek marshes of Dennis and Yarmouthport, where I’ve looked in vain for them every winter for years in my section of the local Christmas Bird Count.
As for that other Arctic raptor of winter, the Snowy Owl, there have been no reports at all east of Hudson Bay or the Great Lakes, which, ominously, is even worse than last year at this time – I suspect it will be another winter with no or very few Snowy Owls on the Cape and Islands. So it looks like, as far as Arctic raptors go, we’ll be “roughing” it this year. But seriously, any birder lucky enough to see one of these rare and enigmatic hawks of the far north will have a leg up on the rest of us.