October is for Roughies!

At the halfway mark of our first official fall season, it’s time to take stock. Fortunately our numbers are posting over at hawkcount.org, so we can see the whole season’s results unfold in one place. We can compare it to previous efforts in 2016 and 2017, and we can compare it to other places in North America.

The numbers can tell us so many things. They can tell us where the raptor flight at Cut Bank fits into the larger story of raptor migration across North America, and the world. It can tell us what the flight is not, of course. Cut Bank is not a hawk migration site where crazy numbers of raptors are counted, like say, at Cape May in New Jersey, where they just counted over 5400 American Kestrels in a single day, or the GEMS site in the Big Belt Mountains of Montana where they once counted 359 Golden Eagles in a day, or way over in the Republic of Georgia at the Batumi Raptor Count, which has tallied one million raptors in the past six weeks. Yes, one million individual birds.

But what they ain’t got, we got, and it’s special. It’s Rough-legged Hawks. These birds are tough, and actually think places like Glacier County are great places to spend the winter. They breed in the Arctic, and are adapted to cold, windy, open environments like those that occur along the Rocky Mountain Front. They have built-in winter gear like any sensible Eastern Front-dwelling Montanan wears ice-fishing or taking a walk to the post office in the winter time: extra warm layers! Their legs are feathered much farther down their legs than a lot of other birds. You Montanans up there might have noticed that Sharp-tailed Grouse put on booties for winter, but Roughies are built for cold and wind all year-round. In addition to their feathered (hence rough) legs, they also have more feathers on their face, much farther down on their bill than some other hawks – like putting on your face mask or neck warmer before heading out into the cold wind.

Ok, back to the numbers – let’s dig in. So far this season, as of October 15, 2018, 108 Roughies have been tallied at Cut Bank.

Let’s put that in context with just the Cut Bank flight. This is our first season with someone counting (almost) daily. Previously, we’ve counted only opportunistically. In 2017, the CBHW tallied a total of 271 Roughies, and more than half of those rolled south AFTER October 15. In 2016, CBHW tallied 236 birds from October 15 forward. So we’re on track to see a similar – if not greater – number of this species pass through Cut Bank during migration this year.

Now let’s put this in context with other migration sites in North America that see this bird in good numbers annually.

In the fall, two of the other sites that see them in appreciable numbers consistently are Hawk Ridge in Minnesota and Vicki Ridge in Alberta. Granted, Vicki Ridge is also a new-ish study site, but they’re just north of us in Cut Bank and make for an interesting comparison. During their first full-season fall count in 2016, they tallied 313. Hawk Ridge’s seasonal counts have ranged all over the place, between only 17 birds one year all the way up to 1123 birds in another.

na_rlIn the spring, this species is a notable component to the flights at Derby Hill and Braddock Bay in New York, and at Gunsight Mountain in Alaska.

In Montana, fall averages (as of 2017) are as shown below. They see them, but not quite like we see them at Cut Bank.

mt_rl

So far this year, the Roughie flight hasn’t materialized at Hawk Ridge (yet!). They stand at 10 individuals as of October 15, 2018.

At Vicki Ridge, they’re at about 56 Roughies as of October 14, 2018.

At MPG Ranch, they stand at 48 Roughies as of October 15, 2018.

At GEMs, they’re at 8 Roughies as of October 15, 2018.

Long story short, we’re interested to see over time if the CBHW is a consistent location to observed Rough-legged Hawk migration in the fall, so we can learn more about this tough wind-rider of the open country. So far, so good!

 

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