Electrifying deterrents: wolves and fladry

Fladry in the wind. (Photo by Nathan Lance, Montana Fish, Wildlife and Parks)

Fladry has proved to be an interesting and rather low-tech tool to ward wolves away from domestic livestock in certain conditions. It consists of red flags or pennants attached to a piece of twine or thin rope at regular intervals (about 18 inches or so) and strung around a livestock corral or pen. Like all predator deterrents, it has some limitations.

For one thing, it depends upon the livestock being concentrated in one area — I’m told that it’s tough, and expensive, to string this stuff up around expansive ranges. For another, it loses its effectiveness over time as wolves become accustomed to seeing it. Part of fladry’s success, it seems, is that it’s a new object that causes wolves to become frightened of passing it. Past studies have shown that fladry can be effective in field trials for up to 60 days before wild wovles cross them (Musiani 2003).

In the race of cunning to outwit wolves, some intrepid thinkers came up with the idea of running electric current through fladry to extend its usefulness. Perhaps a little electric shock would ward wolves off for longer, the thinking went. The negative stimulus of electric current works in theory much like the electric-collar on your pooch that tests the boundaries of its yard. (Except, in the case of turbo-fladry, the goal is to keep the wolves out; whereas you want to keep your dog in, but nevermind, you catch my drift…)

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Book Review: The Wolf’s Tooth, by Cristina Eisenberg

The Wolf's Tooth, cover (Island Press)

If I could use only three words to describe The Wolf’s Tooth, these are the ones I’d choose: elegant, forceful and fluid.

This is a story about how two intertwined ecological concepts — keystone predators and trophic cascades — leave their signatures upon entire landscapes. The Wolf’s Tooth is authored by Cristina Eisenberg, a PhD candidate at Oregon State University who studies conservation biology. Before graduate school, she was a journalist and editor. Her dual career paths collide in The Wolf’s Tooth, and the result is a remarkable and timely  story about her own research but also an entire mountain of literature that came before her.

Before I go on, some definitions may be helpful. Trophic cascades are a phenomenon whereby reactions cascade through a trophic web, or food web. Because trophic webs are really giant networks that process energy and nutrients through an ecosystem, when something causes a glitch or a change in the system it ripples through to other levels. Eisenberg studies this concept with a focus on the interactions between reintroduced gray wolves, elk and aspen and willows. This is a three level trophic web, where the wolves eat the elk which eat the aspen and willows. In this system, the wolves would also be known as a keystone species. By definition, these are carnivorous species that are the glue that bind their ecosystem together; without them, things have a tendency to fall apart or shift dramatically. Keystone species exert a disproportionately strong influence on the other species in their systems. For example, in the very real case of wolves being extirpated from Yellowstone National Park, the elk population swelled to great numbers and then ate the aspen and willow stands down to the point that new trees were not growing into mature trees because of over-browsing.

To tell the story of trophic cascades and how we know what we do about them, Eisenberg weaves fluid first-hand accounts of her PhD field work and personal experiences in nature with summaries of foundational studies. Her own field work entailed monitoring aspen and willow stands for herbivory patterns from elk, and correlating these patterns with the presence or absence of wolves and predators in the area. The scenes she bases on her field work transport the reader to the slopes and valleys she worked in Glacier and Yellowstone national parks, the H. J. Andrews Experimental Forest in Oregon and elsewhere. As a reader, you experience what she does: you discover a coyote carcass with its throat torn out by wolves, clear evidence of a territorial dispute; you tiptoe through a den site littered with the chew toys of wolf puppies; and you feel the hair on your neck raise when a moose is taken down by wolves only a few hundred yards from Eisenberg as she’s wrapping up a transect line. The sheer force of her narratives thrust you into the journey she’s embarked upon to understand how species interact in the web of life.

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Coastal northwest American marten conservation

American marten. (Photo credit unknown.)

Just how many sub-species of American martens are living in California and Oregon? Well, there may be one less than experts thought, according to a 2009 study published in Conservation Genetics.

American martens (Martes americana) are slightly larger than a house cat and are carnivorous members of the Mustelid family. They live in boreal forests and are widely distributed across Canada, but they are also found in mountainous and coniferous forested areas in Washington, Oregon and northern California, as well as south through the Rocky Mountains to northern New Mexico. While the populations in Canada are largely contiguous due to the comparatively more intact forests there, populations in the U.S. tend to be fragmented. This is in part due to the animals moving into what’s called Pleistocene refugia — areas where the climate is more akin to the cooler, drier times of the Pleistocene, which are generally areas of higher-elevation — and also in modern times, habitat encroachment such as logging and development.

American martens also prefer mature forests, and much of the old-growth forests have been cut down. If memory serves, about 5 percent of our original old-growth forests remain here in the U.S. Because they are so tied to these dwindling habitats, and because they were historically over-trapped for their fur, the species has been on conservationists’ radar screens.

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Guest post: Cristina Eisenberg, “The Mark of the Wolf’s Tooth”

I’ve not yet read Cristina Eisenberg’s book, The Wolf’s Tooth: Keystone Predators, Trophic Cascades, and Biodiversity, but it sure sounds like something I’d enjoy. Recently, a publicist from Island Press contacted me and asked if I’d re-post a blog entry Cristina wrote about her research and travels in Waterton-Glacier International Peace Park. I’m happy to oblige, because her writing is so engaging. – DeLene

Cristina Eisenberg

Spring comes to the northern Rocky Mountains like a lion and often leaves like one too. This spring proved no different. I spent it in Waterton, Alberta, resampling eighty miles of track transects I had created three years earlier, looking for changes in wolf and elk use of this critical wildlife corridor. My study area in Waterton-Glacier International Peace Park spans the US-Canada border and harbors most wildlife species present at the time of the Lewis and Clark Expedition.

Track transect surveys are among my favorite fieldwork, because this method allows me to experience landscapes intimately. Walking along the same pathways that wolves and elk use, I pull measuring tape in fifty-yard increments and record all the large mammal animal sign I find along a two-yard strip on either side of the tape. Along the way I often find unexpected and fascinating things and secret places—coyote dens, wolf rendezvous sites, a newborn elk bedded in the shrubs, and the place where a grizzly sow has lain with her cubs. However, this method can only be applied between snowmelt and when the grass grows tall enough to hide the data (wolf and elk droppings, carcass pieces). This May, five snowstorms made our work more challenging than usual, effectively burying my data and immuring us in our quarters for days.

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Stressed out cattle and elk?

{Thanks to PLoS-One for picking this post for their Blog of the Month competition. My winnings? A free T-shirt with a PLoS open-access word cloud. Pretty neat.}

Photo: USDA Agricultural Research Service

Can the mere presence of a wolf stress a prey animal so much that they lose weight? New research says, Yes, maybe so.

When I was working on my master’s, I interviewed several cattle ranchers in the Southwest — namely, Arizona and New Mexico. I was looking for their beliefs and opinions about Mexican wolf reintroduction, and an oft-repeated claim was that the mere presence of the wolves was stressing their cattle, resulting in lower weights. And a skinny cow never made anyone any money, so that was a problem, they said. Wolf conservationists laughed in my face when I told them about this complaint.

But biologically speaking, is there something to it? A new study by a group of Canadian researchers found that both domestic cattle and wild elk change their behaviors when wolves are around; and this often costs the animals energy, they say. Until this past August, Defenders of Wildlife offered a compensation program that paid ranchers for wolf-killed cattle and other domestic livestock in the Northern Rocky Mountains and in the desert Southwest where wolves were being reintroduced. Had they continued it, perhaps they would have been asked to compensate ranchers not only for wolf-killed cattle, but also for cattle that did not grow out to whatever the rancher’s historic average was due to “stress” from wolves. (How you would separate this variable from changes in forage due to drought, I have no idea.)

For this study, the authors guessed that the artificial selection of cows over the years, for domestic breeding purposes, may have resulted in the loss of behaviors that you may expect from wild animals, such as elk, when faced with the stress of being eaten by a predator such as a large gray wolf. Or, they wrote, artificial selection of cows may have resulted “in erratic and inconsistent responses.” 

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Suburban Howls, by Jon Way

Suburban Howls, by Jon Way

Suburban Howls: Tracking the Eastern Coyote in Suburban Massachusetts is a documentation of research on coyotes done by Jon Way while he was at Boston College and earning a PhD. He tells anecdotes about coyotes he caught during the multi-year study of coyotes in Boston and its surrounding suburbs as well as Cape Cod; and he tells anecdotes about the frustrations of working in an urban area. While it’s fascinating to learn about the life histories of the animals he studies, it’s equally heartbreaking to learn about their deaths at the hands of hunters, drivers of cars, and in one rare case a poisoner.

Way’s writing is at times detached, in the way you might expect a wildlife biologist to discuss their animal subjects. But these moments are few and far between. The bulk of the book is emotionally charged. It’s a rare look into the inner mind and emotions of a scientist going about his research. He’s not shy at disclosing snags he hit with the Massachusetts state wildlife agency and a zoo he was initially partnering with.

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Putting a number on it: Maned wolf survival rates

Chrysocyon brachyurus, maned wolf, in Cologne Zoo, Germany. (Wiki Commons, image by sarefo.)

How can you conserve a large carnivore when you don’t know how many of them exist? It’s a difficult task, and so a few scientists at the Jaguar Conservation Fund opted to put a number on their target population… only it’s not jaguars they were trying to pinpoint, it was the lesser known maned wolf.

The maned wolf is a quirky-looking wild dog relative that looks rather like an over grown red fox whose legs have been comically elongated. Or a skinny wolf on stilts. Though it is in the family Canidae, it’s not in the genus Canis as are true wolves… rather, it is in a related genus and is named Chrysocyon brachyurus. My reading of Tedford and Wang’s book, Dogs: Their Fossil Relatives and Evolutionary Origins, indicates that these researchers believe the South American canines, including Chrysocyon, evolved from a group closely related to, but separate from, Canis.

Today, the maned wolf lives in Brazil, Paraguay, eastern Bolivia and northern Argentina where mated pairs maintain territories from 30 to 80 square kilometers, according to the study. But the pairs do not hunt together, rather they go after prey individually. The largest portion of the animals range lies within Brazil in what’s known as the Cerrado or Brazilian savannah. This area is being rapidly converted to cattle ranches and agriculture, the authors state.

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Warming caves: A stop-gap prevention to thwart white-nose syndrome?

Little brown bats in NY hibernation cave. Most of the bats exhibit fungal growth on their muzzles. Photo by Nancy Heaslip, NY Dept of Environ. Conservation.

I’ve been trying to tune into developments with white-nose syndrome because it’s one of the worst emerging pathogens to hit North American wildlife in recent history. Ever since the first breakout in a New York cave in February 2006, this white fungus has killed off well more than a million bats from six different species. Sure, I know, there was some quibbling over whether the fungus was causal or secondary, but the bulk of the evidence seems to be pointing to it being causal. And for my story, a conservation biologist I interviewed at Bat Conservation International said, “We think the fungus is clearly the smoking gun,” so that cinched it up for me.

But I didn’t know, when I filed that story, about a research paper published March 5, 2009 in Frontiers in Ecology and the Environment, in which two authors offered experimental evidence based on computer models that artificially warming caves or mines throughout a bats hibernation period may thwart the disease process enough to quell the winter carnage. The paper says that by offering bats “thermal refugia” of 28C (about 82F) degrees, survival rates could be increased by up to 75 percent. This is premised upon the idea that bats are forced to burn through their fat stores too fast when infected by the Geomyces destructans fungus that causes WNS, because the skin infection itches and rouses them from their hibernating slumber. Being roused multiple times during hibernation then causes their metabolism to speed up, and they grow hungry due to running through their stored energy, forcing them to leave their caves too early and then starve for want of insects in mid- to late-winter.

Because G. destructans is a cold-loving fungus, the thermal refugia might also halt its growth on individuals during winter months. It is thought to be temperature limited at about 20C (68F), according to the paper’s authors. Because several different species of bats tend to use the same hibernation sites, called hibernacula, thermal refugia may also to help limit transmission between species.

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How much for that tiger skin?: Modeling illegal wildlife trade markets

Tiger skin confiscated by authorities. Police annd officials say there is an indication that traps are being set for tigers. Photo courtesy of WWF-Indonesia.

While a lot of attention is paid to reporting on human warfare across the globe, the illegal war on wildlife that is carried out through trafficking, poaching, and bush meat trades is often given comparatively less coverage. (At least in U.S. mainstream media, to which I refer here.) I’ve been starting to pay more attention to wildlife trafficking issues for a few reasons. One being a story I wrote recently for Birder’s World magazine (you’ll have to wait until February to read it!) where I interviewed a Florida Fish and Wildlife Conservation Commission agent who told me about people smuggling Cuban bullfinches into Miami. He said the smugglers give the birds Valium to knock them out, then stuff them in shaving cream cans for the short flight to the U.S. Te visual that provided nearly made me retch in disgust. I grew up in Florida, but had no clue this was going on six hours south of my home. (The BW story is not about Cuban bullfinches, by the way).

One of the things that makes wildlife trafficking so hard to fight is law enforcement’s ability to detect it (well, that and political will). And because the trade is illicit, it’s often hard for researchers to pin a number on the problem and to be able to say that a species is declining by X percent because of poaching. So a recent paper on developing methods to model illegal wildlife

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What’s the best dog breed for guarding livestock?

The akbash dog breed. (Credit: Tamara Taylor, Patteran Akbash Dogs, http://www.akbashdogs.com)

Using guard dogs to protect livestock herds from predators like wolves is akin to using nature to fight nature. And that is something I can definitely get behind. It’s a way better idea than opting to shoot or trap or poison the predators; which has led to them being scarce across the landscape and has induced all sorts of trophic changes that altered entire eco-regions and systems. But what kind of dog works best to protect goats, sheep and cows? Surely not just any dog can face off with a bear or a wolf and convince the wild carnivore to turn back from a buffet of plump sheep or newborn-naive calves?

A new review paper searches the existing literature on livestock guard dogs and offers up some tried-and-true answers. The authors are two Wyoming sheep producers, and the review was funded by the Wyoming Wool Growers Association. It was published in the Sheep and Goat Research Journal (can’t say I’ve perused that one before!) which is backed by the American Sheep Industry Association. A sheep rancher, a livestock association — these are normally the entities you might see on the anti-predator side of a Notice of Intent to Sue letter threatening to petition to de-list an endangered carnivore, like wolves, from the Endangered Species Act. So I was pretty excited by the clearly progressive and forward-looking position taken in this paper, which is that carnivores are coming back, and big ones at that, so livestock producers need to up the ante and try using every tool at their disposal to protect their sheep, but to focus on tools that are non-lethal to the carnivores. <Wow. I’m kind of slack-jawed, I admit. And oh so hopeful that there is more common ground here than the mainstream media might have us believe.>

One of the problems posed by using livestock protection dogs, or guard dogs as I generally call them, is that they may die. And in general, if a rancher is making an investment in a pro-active method to protect her or his livestock, they want that investment to last. While you do have to acknowledge that the guard dog you put out there may die in a conflict with a bear or a wolf, you want to choose your dogs wisely and pick a breed that minimizes this risk. And for a wolf conservationists point of view, any sort of proactive method like this that prevents a livestock conflict or loss from occurring in the first place is a good thing, and a positive step toward livestock and wolves coexisting. 

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