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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Bedeviled Tasmanian devils

Tasmanian devil (no photographer information available).

Wild Muse just perused the latest issue of Conservation Biology and went foraging for substantive research to post about… Hold on tight because we are going to Tasmania. To the Forestier peninsula in southeastern Tasmania, to be exact – where Tasmanian devils are pinned down by a catastrophic disease.

Unfortunately, it will not be all fun and games on our trip Down Under (well, under Down Under, really). As everyone is likely well aware by now, the Tasmanian devil (Sarcophilus harrisii) faces a perilous future due to a nasty infectious disease plaguing its geographically-restricted population. Infectious facial tumors are killing off devils at an alarming rate. The devils most-often contract the infectious cancer cells when they nip and bite each other during fights. Males will often fight vigorously for breeding rights with females. All it takes is a direct transfer of living infectious nerve cells from one to the other and bingo!, transmission is complete.

While some research has focused on the disease origin, mechanism and transmission, other researchers have turned their attention to ways to manage the devil population and reduce Devil Facial Tumor Disease (DFTD) in the wild. A group of researchers led by Shelly Lachish and working out of the School of Integrative Biology, Univ. of Queensland, Australia set out to test whether or not selectively removing infected individuals from an experimental colony of devils would alter the rates of infection within that colony as compared to a control colony. The experimental colony was located on the Forestier peninsula, and the control was located on the Freycinet peninsula on Tasmania’s east coast. Both locales have similar climates and habitat (open, dry forests and low-lying heath).

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Red wolf (video)

Just found this neat video from the BBC about red wolves. It shows two wildlife vets and one red wolf program biologist capturing a red wolf that lives in captivity as part of the captive breeding program. I’ve traveled to the facility where this was filmed in North Carolina, and have stepped inside these wolf pens (yes, when wolves were in them). The animals get very excited when people are around, and they typically run along the perimeter of the pens trying to keep as much distance as they can between themselves and the humans. Despite being “scary predators,” I think this video shows that they are much more scared of us than we are of them.

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The wolves of Ethiopia

Ethiopian wolf (c) Michael Gunther

When most people hear the word “wolf,” they think of the burly gray wolves of the Great White North. But wolves are present all over the world, even in Africa. The Ethiopian wolf, Canis simensis is incredibly endangered. As its name implies, it lives in Ethiopia, but it lives only in seven highland mountain ranges, above the tree line, from 3,000 – 4,500 meters. It is distributed north and south of the Rift Valley. (It is also the only wolf in all of Africa.) These wolves live in social packs, but the animals hunt individually for the most part. They are rodent specialists, but occasionally also hunt antelope and lambs together. {1} Their territory averages about 6 square kiolmeters, and their packs number about 3 to 13, averaging around 6 members with one breeding female. This video is taken from the BBC’s “Life of Mammals” and features an Ethiopian wolf hunting:

(You gotta love David Attenborough!)

To hear them howling, visit this page. Superficially, this wolf looks similar to a fox which led some naturalists to think it was more closely related to foxes of the genus Vulpes than it was to canids of the genus Canis. It’s also been thought to be a type of jackal. But today, most systematicists and taxonomists think it is more closely aligned with wolves.

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Q&A with landscape ecologist Tom Hoctor

Tom Hoctor

Tom Hoctor is a landscape ecologist and conservation biologist who directs the Center for Landscape Conservation Planning at the University of Florida. Tom earned his undergraduate degree at Harvard University and his doctorate at the University of Florida. He’s recently undertaken the challenge of contributing to work on the Florida Wildlife Corridor. He’s also a friend of mine, from my hometown in Gainesville, and a kick-ass bird watcher. I asked him to answer a few questions for an ad-hoc series I hope to do here on Wild Muse that will explore the work of scientists, conservationists and their inspirations.

Florida has a unique history of settlement, development, and exploitation of natural resources. What do you think are the biggest defining conservation problems the state faces?

Sea level rise is likely the biggest problem that will define Florida’s future. Given the size of Florida’s coastal human population, and the extremely flat topography, Florida stands to be impacted more than any other state by sea level rise, and even a 1 meter rise in sea level could have catastrophic consequences. It is already extremely difficult to balance continued development with environmental conservation in Florida, but sea level rise will greatly complicate this balance with the potential shift of millions of people away from the coasts to currently rural inland areas that are extremely important for conservation.

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Mesopredators gone wild

Red fox, Vuples vulpes.

Are we headed toward a world full of foxes, skunks and raccoons — but empty of lions, tigers and bears? Maybe. It’s a fact that many of the planet’s large carnivores are in dire straits. Where I live in the eastern U.S., we no longer have cougars or eastern wolves, top predators that used to range across the East several hundred years ago. Cougars are now geographically restricted to just the southern tip of Florida, where about 100 Florida panthers live in marginal habitat. And eastern red wolves are now confined to a tiny speck of land in North Carolina, where about 100 live in a managed population. Both species are listed under the federal Endangered Species Act. In their absence, entire ecosytems have changed.

Ecologists have long struggled to quantify what happens to an ecosystem when the top predators are lost.

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Clouded leopard cubs’ mugs steal the show

I received a press release today from the Smithsonian Institution’s National Zoological Park stating that the sexes of a pair of clouded leopard cubs born at their Conservation Biology Institute campus are now known to be males — both of ‘em. Clouded leopards are highly imperiled cats of Southeast Asia and these two little siblings are products of a captive breeding program. And if you aren’t suckered in by the cuteness of their mugs alone, consider that these two little Romeo’s were born on Valentines Day, just thought I’d throw that in there to sweeten the pot on their cuteness factor! One weighs 4 pounds 9 ounces, the other is two ounces less. Check these little brothers out:

Clouded leopard cubs. (Courtesy of the Smithsonian Institution National Zoo.)

The release states that “the cubs now ‘chuff,’ which can be described as a puffing sound and is considered a sign of recognition.” (I don’t know if it is at all the same sound, but my half-Maine Coon cat used to make a puffing-huffing sound when he was really excited about playing or being fed. He only did it when he was very satisfied, or very excited, and it was a sound we always cherished for its richness.) I did not know this before reading the press release, but SI has the largest captive clouded leopard population in the United States.  You can read more about it here. My writing here on Wild Muse tends to skew toward the canids, so I hope this makes the felid-lovers out there happy.

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Tiny little red wolves

Red wolf puppies, about two weeks old, in a shallow den located within Alligator River Wildlife Refuge, N.C. Two of these four are 'foster' puppies that were just placed within the den. (© 2010 DeLene Beeland)

The red wolf is one of the rarest mammals in North America, only about 80 live in the wild on the Albemarle peninsula which juts into the Atlantic Ocean from North Carolina’s shore. And right now is puppy season.  Female red wolves give birth to litters as small as one or two, or as large as 10, in April. And that’s when work gets really busy for the red wolf recovery program biologists. About 50 were born this year, and the Red Wolf Recovery Program staff are still in the process of finding all the dens and documenting the litters. I spent today shadowing several program biologists in the field, and it was a very special day. Sometimes, the program slips extra red wolf puppies into a mother’s den. They get the extra puppies from captive-breeding facilities that are contributing to the species continued existence on earth. And yes, red wolves they take from captivity and foster into a wild den are pure red wolves.

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Begging meerkat pups

Meerkats, © Roberta Stacy

Learning about animal behavior never fails to fascinate me, and so it was with great interest that I read a recent paper on how meerkat pups alter their food-begging behavior depending upon the adult meerkat that they are nearest to. {1} Not all adults are created equal, it seems, in the world of a meerkat pup. And because these creatures are cooperative breeders, pups aren’t “stuck” with their birth parents. They have their choice of food-givers to hit up for a meal. Even better, some adults dole out food at a higher rate than others — leaving scientists wondering if the pups were preferentially seeking them out in order to maximize their food intake. Evolutionarily, it would make sense that a clever pup would hone in on the foodiest adult and put on a begging show, but that isn’t exactly what the researchers found.

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“Skunk bear” snowfall ecology (a.k.a what wolverines want)

Adult wolverine, displaying "golden mantle." © U.S. National Park Service

Recently, the only known wolverine in Michigan passed away. Unlike the life and death of most wild animals, which unfold without human fanfare, her life and death were noticed. Scrutinized even. Rare species catch our attention. Rare species persisting outside their normal range even more so. Wolverines are often characterized as solitary creatures, thinly distributed across their range. But just what do wolverines require for habitat?

There’s been some chatter of Gulo gulo expanding southerly in the lower-48 states. They are comparatively more common in Canada, but some sightings have been reported in California’s Sierra Nevada mountains, Oregon and Washington, as well as Colorado and Idaho. Now, a group of researchers has compiled a strong argument that wolverine distribution may be best described as a function of spring snow cover coupled with a summer heat limit of less than 71.5 degrees Fahrenheit.  J.P. Copeland of the U.S. Forest Service’s Rocky Mountain Research Station in Montana and 16 other international researchers have published their hypothesis in the Canadian Journal of Zoology. {1} They examined satellite imagery of spring snow cover at the end of the wolverine’s denning period (last week of April to mid-May) to determine wintry limits of good wolverine habitat in North America and Eurasia.

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