I was pleased to see the fall issue of Human–Wildlife Interactions (a peer-reviewed journal focused on
human/wildlife conflicts, published by the Jack Berryman Institute of the University
of Utah) included a paper by our local USDA Wildlife Services Supervisor Rod
Merrell. Rod’s paper outlined some successful methods to mitigate conflicts with
ravens in industrial areas.
Here’s a picture of Rod setting a snare for a bear that was
killing our sheep a few years ago.
Common ravens are federally protected under the Migratory
Bird Treaty Act, so when ravens cause problems, solutions generally involve
federal wildlife officials. As an ag producer, I’ve had to call on Rod for help
with ravens on my lambing grounds, but industrial companies have unique
challenges when it comes to ravens at their facilities (including coal and
trona mines, gas facilities, and power plants) since shooting, harassment and
destruction of nests are not allowed without a special permit from the U.S.
Fish & Wildlife Service.
Nesting ravens can be very aggressive towards workers coming
near their nests, which can be built on catwalks, stairwells, derricks and
smoke stacks, but most raven complaints at industrial facilities involve
roosting ravens. While a few ravens aren’t often much of an issue, Rod is
called to respond to cases involving 150-300 roosting birds and the health and
safety issues caused by their fecal material deposited on equipment, handrails,
stairs, and other surfaces that workers routinely contact.
Rod’s excellent five-page paper only discusses methods he
has personally used to mitigate raven conflicts, from the use of lasers,
hazing, scarecrows, sirens, propane cannons, avicides, shooting, and –my favorite–
effigies. The paper acknowledges that ravens are intelligent birds with
remarkable eyesight, and an acute sense of smell.
Rod reports, “Based on my experience, effigies are the most
effective means to keep ravens from roosting on towers, tanks, cable trays, and
other elevated structures.” After experimenting with a variety of effigies
(including fake ravens used as movie props, which were quickly “torn to pieces”
by ravens), Rod recommends the use of actual dead ravens, hung upside down where
the wind will create some movement. His paper goes into specifics about the
placement of effigies (and how they must be properly disposed of according to
federal permit guidelines when no longer needed), but I won’t go into detail
here.
Rod also acknowledges that breaking up a roost is a
process, “often time- consuming, frustrating, and requiring follow-up,” and no
single technique will resolve the problem.
“One
must reinforce danger with other tools and techniques or the ravens will
habituate to the natural effigies with time,” he wrote.
But what
I love about this paper is the endorsement of the value of effigies – a
practice used by traditional agrarians around the globe. Sometimes ancient
methods are proven to be the most effective. I would include the use of
effigies, livestock guardian dogs, and spiked collars as ancient tools that are
still proven in value today.
Here’s
a scene from rural Turkey in October 2010. Turkish guardian dogs tethered, with
a dead wild boar, chickens scratching nearby, and an effigy of a Eurasian
Magpie hanging from a piece of farm equipment.
Steve provided these shots from our late friend Aralbai's place in Mongolia. These images were taken during Steve's first hunts with Aralbai in 1997 (adventures that involved fox, feasts & drinking). The scare magpie hung adjacent to Aralbai's corrals during the lambing season.
7 comments:
Is "effigy" the right word if it is a real deal bird, as that magpie appears to be?
Chas, you're probably right, but you'll notice we use the words "scare magpie" when pointing to the real dead bird in Steve's images.
Growing up in NE Iowa we had huge elm trees lining our boulevard which, during the Fall, were filled with thousands of starlings nightly. The noise and crap smell was horrendous. My father had read where placing dead starlings in the trees would drive them away. The police gave us permission to shoot the birds which we did, tied them to string and flung them into the trees. It didn't work. Riding a bike dragging a snow shovel on the street helped.
You got a great story out of it anyway!
"The paper acknowledges that ravens are intelligent birds with remarkable eyesight, and an acute sense of smell."
That is surprising to me. Most birds have a quite poor sense of smell.
That was the conventional wisdom, but more and more birds are proving to smell well. New World vultures first, but also various seabirds, waterfowl, and pigeons as well as Corvids are now being reconsidered.
Turkey smells pretty good.=p
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