Rigor Vitae: Life Unyielding

Saturday, July 01, 2006

EAGLE OWLS OF OLD ENGLAND

Darren Naish has a post up about the Eagle Owls that have begun colonizing Great Britain. Common Eagle Owls (Bubo bubo) are a widespread and spectacular bird of the Old World, found across North Africa and most of Eurasia, but absent in modern days from the British Isles-- until recently. The species looks much like its smaller American cousin, the Great Horned Owl (B. virginianus), but is more heavily streaked and spotted, with stunning orange eyes. The first Eagle Owl I ever saw belonged to my friend Steve, who obtained a pair of the birds several years ago. I said something like, “Wow, she's a lot bigger than a Great Horned, isn't she?” To which Steve replied, “What do you mean, she? This is the male!” The hen was a quarter again his size.

B. bubo is by far the largest and most powerful owl. Like the American Great Horned, it is a generalist predator that takes all manner of mammals and birds, often tackling very large and formidable prey, clinging tightly with bill and both feet until the thrashing stops. It is capable of dispatching a full-grown hare or goshawk. Eagle Owls will not tolerate smaller owls in their territory, and regularly prey on them. Because they are such fierce hunters, British Wildlife officials are rightly concerned about the impact this new species will have on the local ecology, and are trying to work out a management policy for the bird. It seems the question they're trying to answer is whether the owls crossed the Channel under their own power or with human assistance. I inferred from Darren's post that British law makes an automatic distinction between natural colonizers and human-introduced ones. If the owls flew across the North Sea, they are to be protected. If humans brought them, they are essentially vermin, and should be discouraged at the very least. Here in the U. S., wildlife management policy tends to be based on similar parameters, but there's a little more room to take other issues into account—those issues usually being economic interests and economic interests. During the 20th Century, Coyotes (Canis latrans) crossed the Mississippi on man-made bridges, achieving the status of naturalized natives of the eastern U.S. When Sea Lampreys (Petromyzon marinus) made a similar transit into the Great Lakes via shipping canals, they decimated several species of game fish, thereby qualifying as invasive exotics.

In the U.K., the U.S., and elsewhere, I think that wildlife managers could benefit by forgetting this question of “natural” vs. human introduction altogether. I think it comes from a theistic viewpoint, where God doesn't want us tampering with his plan. If there ever was some divine plan of nature, we threw it out the window centuries ago, and it's far too late to worry about it now. The fact of the matter is that animals and plants move around; ranges are constantly changing, and nature is constantly trying to adapt to those changes. Humans impact nature in many ways, some intentional, some not. There is nothing intrinsically good or bad about our impact, and we shouldn't make decisions under such assumptions. What we should discuss is what kind of a world we want to have a century from now. My vote for prime consideration is biological richness and diversity. How the Eagle Owls got to England is irrelevant. Their ecological effect will be the same either way. I have no authority to speak about British ecology; my forays into that land have been restricted to Heathrow Airport. Still, I imagine the owls' effect will depend on their success in their new digs. From what Darren says, it sounds like they're off to a fine start, and there's good reason for English Long-eared and Tawny Owls to be nervous. My own preference would be for a laissez-faire policy on such issues, unless it could be shown that the newcomers presented specific dangers that we feel should be avoided.

Speaking of owls, it's time for an update on my previous posts on vanishing owls of the Wasatch Mountains. Of the eight nest boxes I've installed in previous Flammulated Owl territory, none have been used by any birds, and I've found two new woodpecker cavities that appear to be ideal sites. I have not heard or seen a Flammulated in the past five years. The successful Long-eared Owl nest from two years ago was again unused. A pair of Great Horned Owls and Red-tailed Hawks both nested in that grove of trees this year. I checked the clone of oak trees where I heard a pair of Longears courting this spring, and saw no signs of them. I expect the loss of meadows (where the owls hunt) to housing developments has hurt the birds, but as I mentioned, introduced Raccoons prey heavily on Longears in this area, and appear to be the primary threat. On the night I found this Longear territory, I saw two of the masked bounders. The snow was deep, and I could move much faster on cross-country skis than the 'Coons could. I could have easily killed them with a ski pole, and for a moment actually considered that act of abject cruelty. Laissez-faire wildlife management doesn't come naturally.

The illustrations are not of Common Eagle Owls, but of two African species of Bubo.
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upper: NDUK EAGLE OWL (1995) acrylic 11' x 7"
lower: SPOTTED EAGLE OWL (1998) acrylic 30" x 20"

2 Comments:

Blogger Patty Ann Smith said...

I agree with what you say. "There is nothing intrinsically good or bad about our impact, and we shouldn't make decisions under such assumptions. What we should discuss is what kind of a world we want to have a century from now. My vote for prime consideration is biological richness and diversity."

I also know that the balance between passion and rage these days is often hard to manage.

In my own work at "Hope 4 America"...and the whole world ~ I use simple pictures, words, and music to help reconnect man back to nature. I am so glad I came across your blog recently and discovered the good work you're doing.

~ Patty Ann Smith

8:54 AM  
Blogger cpbvk said...

Thanks, Patty. You said a mouthful there about the balance between passion and rage.

1:07 PM  

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