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!

 

Bird’s eye view of the Cut Bank Creek Coulee

Have you ever wondered what it would be like to see Cut Bank just like the hawks, eagles, and falcons cruising south down the coulee for the winter?

Wonder no more! Follow along the Cut Bank Creek from just north of the train trestle, cross the bridge, then end up just shy of US Highway 2.

The Hawkwatch location itself is just south and east of the trestle (to the left, in the grassy patch just past the bridge). At the end of the clip, if you turned west (right) and took Route 2, you would head straight for the Marias Pass – the dividing line between the Bob Marshall Wilderness and Glacier National Park.

Here’s a Bald Eagle taking the Coulee line south-bound last year:

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Nerdin’ out on the data

What is so interesting about the hawk flight in Cut Bank?

Here’s what’s interesting. For the few hours our volunteer counters have put in over the years, we’ve turned up an unusual species composition and distribution.

The Cut Bank Hawkwatch (N 48° 38′ 27.7″, W -112° 20′ 32.05″) is located in Cut Bank, Montana – 40 miles as the crow flies from East Glacier (along the Rocky Mountain Front), 100 miles southeast of the Vicki Ridge site near Beaver Mines, Alberta, 110 miles north of Roger’s Pass (MT) and 160 miles north-northwest of the GEMS site at Duck Lake Pass (MT). Cut Bank bills itself as a place “where the Rockies meet the plains” but it’s more accurately characterized by glacial topography – where the mountain glacial outwash meets the continental ice sheet outwash. These prehistoric carving, melting and flooding events created a dispersed, lumpy, opportunistic area of updrafts for migrant and resident hawks. The greater Cut Bank area was the location of the Glacial Lake Cut Bank, which overflowed into the Glacial Lake Great Falls. It appears that one of the lake’s drains is now the Cut Bank Creek Coulee, along which the town is situated. One of the better views both to the north and south along the coulee is conveniently located at the town’s main strip mall.

It is, from every angle, a unique site. It is not a ridgeline. It is not a lakeshore or an ocean coastline. It is at the edge of a small town on a prairie, overlooking a small creek coulee. Places of business (food, gear, hotel and restrooms) are immediately at hand. It is accessible 365 days of the year. It has ample parking. It is close to a planned stretch of the town’s growing trail system. Freight trains rattle and bellow as they traverse a picturesque trestle across the coulee along which the flight primarily occurs. On clear days – and most are – Glacier National Park and the Bob Marshall Wilderness are visible on the western horizon. And on a good fall day, Rough-legged Hawks and Harlan’s Red-tailed Hawks blast south-southeast at 20-50 meters directly overhead in the double-digits.

Our current efforts are focused on the fall flight, but a two-season site may be possible to develop.

To the data!

FALL 2016: 352 birds

  • 75 hours
  • October: 8 days
  • November: 2 days
  • December: 1 day
  • Turkey Vulture: 0
  • Osprey: 0
  • Bald Eagle: 7
  • Northern Harrier: 9
  • Sharp-shinned Hawk: 13
  • Cooper’s Hawk: 1
  • Northern Goshawk: 2
  • Red-tailed Hawk: 44
  • Rough-legged Hawk: 236
  • Swainson’s Hawk: 0
  • Ferruginous Hawk: 2
  • Golden Eagle: 12
  • American Kestrel: 1
  • Merlin: 3
  • Peregrine Falcon: 0
  • Prairie Falcon: 8
  • Unknown Buteo: 11
  • Unknown Falcon: 0
  • Unknown Eagle: 2
  • Unknown Raptor: 1

FALL 2017: 827 birds

  • 99 hours
  • August: 1 day
  • September: 7 days
  • October: 15 days
  • November: 4 days
  • Turkey Vulture: 0
  • Osprey: 2
  • Bald Eagle: 64
  • Northern Harrier: 50
  • Sharp-shinned Hawk: 31
  • Cooper’s Hawk: 6
  • Northern Goshawk: 1
  • Broad-winged Hawk: 7
  • Red-tailed Hawk: 145
  • Rough-legged Hawk: 271
  • Swainson’s Hawk: 81
  • Ferruginous Hawk: 48
  • Golden Eagle: 38
  • American Kestrel: 9
  • Merlin: 10
  • Peregrine: Falcon 3
  • Prairie Falcon: 20
  • Unknown Buteo: 25
  • Unknown Falcon: 1
  • Unknown Eagle: 1
  • Unknown Raptor: 1

SPRING 2017: 544 birds

  • 71 hours
  • February: 3 days
  • March: 14 days
  • April: 4 days
  • Turkey Vulture 2
  • Osprey 2
  • Bald Eagle 107
  • Northern Harrier 22
  • Sharp-shinned Hawk 17
  • Cooper’s Hawk 11
  • Northern Goshawk 0
  • Red-tailed Hawk 117
  • Rough-legged Hawk 86
  • Swainson’s Hawk 0
  • Ferruginous Hawk 45
  • Golden Eagle 90
  • American Kestrel 7
  • Merlin 2
  • Peregrine Falcon 2
  • Prairie Falcon 13
  • Unknown Buteo 9
  • Unknown Falcon 0
  • Unknown Eagle 0
  • Unknown Raptor 7

The standout Rough-legged Hawk, Ferruginous Hawk, and Prairie Falcon flights have yielded some of the highest tallies west of the Great Lakes with only casual effort for 2 years running. In Canada, the Rocky Mountain Eagle Research Foundation’s Vicki Ridge site (near Beaver Mines, AB) logged 282.63 hours during the fall of 2016, with 313 Rough-legged Hawks, 3 Ferruginous Hawks, and 10 Prairie Falcons. The GEMS site in the Big Belt Mountains of Montana have logged 2 full fall seasons in 2016 and 2017 (389.17 hours, 256.23 hours) with an average of 146 Rough-legged Hawks, 1 Ferruginous Hawk, and 11 Prairie Falcons. Far to the north at Gunsight Mountain in Alaska, 2 full-season spring counts (2016 and 2017, at 485.33 and 514 hours) have yielded an average of 260 Rough-legged Hawks.

We’re really excited to see what we can pull out of the sky with a counter or 2 on the ground on a consistent basis this coming fall.

If you want to grind out the data yourself, please check it out at HMANA‘s wonderful Hawkcount.org, and please do consider donating to this wonderful organization while you’re there. They keep the data free. It’s only one of many, many good things they do!

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