‘I’m not a Golden Eagle,’ screamed Swainson’s Hawk

COFFEE WITH WARREN, with Warren Harbeck
Cochrane Eagle, September 10, 2008

A Swainson’s Hawk  is “as different from a Golden Eagle as chalk from cheese,” says Golden Eagle expert Peter Sherrington. Photo of juvenile Golden Eagle, left, by Jim Weaver, The Birds of North America Online; photo of juvenile Swainson’s Hawk, right, by Bill Hargarten.

It’s clear from last week’s gaffe that Bill Hargarten and I know our cameras far better than we know our raptors.

No sooner had the e-mail edition of my Sept. 3 column, “Golden Eagle likes coffee companion’s pocket camera,” gone out than science textbook editor Christa Bedwin responded with a challenge that sent Bill and me on a delightful journey of learning.

“That's not an eagle,” she said; “it's a hawk!”

By the end of the week, a whole flock of Cochrane’s eagle-eyed birdwatchers were approaching me with the same opinion: Last week’s great photo by Bill is of a Swainson’s Hawk.

“The bird is a light morph juvenile Swainson's Hawk, as different from a Golden Eagle as chalk from cheese!” exclaimed world-renowned Golden Eagle expert Peter Sherrington, formerly of Cochrane and now living in the Crowsnest Pass.

It’s certainly not a Golden Eagle, agreed avid birder Mike Veloski. “Even immature Golden Eagles are mostly dark brown, except for small patches on the underwings. And unlike the Swainson’s Hawk when perched, its wings extend longer than its tail, which itself is distinguished by dark tips set against a white band.”

There was no doubt about the identification in the mind of Trumpeter Swan expert Len Hills, either.

“The hawk in question is a Swainson's Hawk,” Len wrote. “The light coloured head is in contrast to the dark head of the Golden Eagle. Colour and apparent small size are also that of the Swainson's.”

Artist and folk philosopher Barry Mach contrasted Golden Eagles and Swainson’s Hawks by their “leotards.” Unlike Goldens, he said, Swainson’s are not feathered to their toes.

While still focusing on Swainson’s, Barry redirected the discussion from identification to conservation, noting the bird’s “marvelous come-back story” after great numbers were killed off by an insecticide some years ago in their South American wintering grounds.

I asked Peter, a passionate conservationist, about this. He said:

“The cause of Swainson's Hawk deaths in Argentina some 10 or so years ago had to do with a specific poison used to kill grasshoppers which are the species' principal food on their wintering grounds on the Pampas. (The bird’s Spanish name is Aguilucho Langostero, or ‘grasshopper hawk.’). This resulted in direct poisoning of the birds, and the resulting piles of corpses quickly led to cessation of the use of the poison, but not before around 10 per cent of the world's population of the species was eliminated.”

He then went on to describe the picture for Golden Eagles.

“The migratory population of the Golden Eagle that I have been studying for the last 17 years has apparently declined by more than the Swainson's Hawk’s as a result of winter mortality mainly in the US and Mexico. Here the cause is anything but simple and involves human population growth, structural drought related to climate change, removal of prey species, direct killing of the birds for (illegal) commercial purposes, accidental killing through poison baits put out for coyotes, etc., and dozens of other factors directly and indirectly associated with human activities.”

Where’s the political will to do something about this, he asked. “Probably about 60 per cent of the world's bird species are in a similar boat!”

It’s this kind of concern that underlies much of what backcountry professional and fellow Cochrane Eagle contributor Pam Asheton writes in her outstanding column, “Walking the Land,” always worth reading (www.pamasheton.ca).

Well, folks, you’ve certainly given us quite a lesson. As Bill said on behalf of both of us, “I owe your bird-loving coffee companions a ‘thank you’ for setting me straight.”

© 2008 Warren Harbeck

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