The Blog

Childhood curiosity led to puma project

SF Chronicle profile piece. The image above is a flyer for a movie inspired by the article which my graduate students will be producing.

Professor Chris Wilmers waggled the head of the fake deer in the equipment room of his UC Santa Cruz laboratory to demonstrate how alluring the contraption could be to a hungry cougar.

The purpose of the bobblehead deer – stored between a table covered with radio collars and a refrigerator full of cougar skulls, teeth, hair and scat samples – is to provoke mountain lion attacks.

Read on here.  Or if the link doesn’t work, try the pdf (SF Chronicle Profile Aug 12 2013).

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Cal Academy of Sciences – Local Lions

Apparently this video is playing on the big screen in the Cal Academy of Sciences in San Francisco.

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Declining fortunes of Yellowstone’s migratory elk

This press release from Ecology nicely summarizes our recent Ecology paper in a forum discussing the fate of Yellowstone’s migratory elk.

“I think Middleton has an intriguing idea, and it might be what’s happening. We offer another hypothesis that also fits the data that they have. He says it’s climate change on the summer range and more predators on the summer range. I think it’s because there is irrigation that provides the sedentary elk with food. And I think it’s also that there is predator control outside the park,” said Wilmers.

While wolves and grizzlies have been thriving inside the park, predator control measures have intensified outside the park, Wilmers said. “My hypothesis is that in that crucial winter period, the migrants are coming down to range that the resident elk have already been feeding on all summer, and now they are competing for in the winter,” he said. To distinguish between these two stories would require hypothesis testing, he said – pitting them against each other and testing them with more data.

Read the entire press release here.

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Could an Alaska mining project jeopardize Earth’s largest bald eagle gathering?

High Country News article about our lab’s work in Alaska.

… By late morning, eagles are all around us. “Look at that eagle party across the way,” says Taal Levi, a wildlife ecologist with the Cary Institute of Ecosystem Studies, whose tales of this ecological mother lode inspired Wheat’s doctoral project. He points to 50-plus eagles bunched in cottonwoods beyond the river, explaining that since they’re not breeding, they’re less territorial. “Though they do like to steal from each other.”

As if on cue, an adult chases a young bird from some bait near a remote-controlled net gun, and bingo — Lewis flips the switch. Like a starter’s pistol at a track meet, the gun’s crack sends us dashing toward our catch.

Lewis carefully extracts feathers from the netting. He pops a hood over the giant raptor’s head, covers its shiny black talons with handmade leather booties, then hands the bird to Wheat, who cradles it against her chest as she heads back to the road.

At almost 15 pounds, it’s clear we’ve got a female. She’s fearsome, with a massive hooked beak and flesh-shredding talons that curl around Lewis’ exposed fingertips after he takes off a bootie to give us a peek. Yet she sits calmly as Lewis threads a Teflon harness with the GPS under her wings and around her chest, positioning the device just behind her head. Her breast feathers feel silky and warm against the frosty air.

Wheat clips a few of them for stable isotope analysis, which ecologists have long used to infer an animal’s diet based on the levels of carbon and nitrogen. Wherever birds forage, the elements in the food suffuse their feathers as they grow. Wheat hopes the approach, tested in songbirds but not eagles, will tell her where the migrants lived and fed before she tagged them.

Read the whole article here.

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Urban drifter: Mountain lion visits Santa Cruz

It was a crazy day.  A mountain lion made its way into downtown Santa Cruz, and we got a call from the police to come help them and the CA Dept of Fish and Wildlife anesthetize the cat and move it to safety.  Lots of coverage on this one.  Read about it in the Sentinel (with photos here), Pajaronian, Fox News, NBC News or our blog post about it on SantaCruzPumas.

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Top Cats: How Pumas and Other Apex Predators’ Populations Affect The Big Biodiversity Picture

Here’s a great article by Liza Gross in KQED’s Quest.  It ties our recent puma work nicely together with other work on predator effects on ecosystem function.

These “top down” trophic cascades, which the ecologists dubbed “trophic downgrading,” have been documented from the poles to the equators and every major biome in between, making the loss of top predators, they wrote, “arguably humankind’s most pervasive influence on the natural world.” Earth has weathered five mass extinctions but never before at the hands of one species—human beings. And we humans seem hell bent on clearing the Earth of larger bodied apex predators.

I considered all this as I read a new paper from wildlife ecologist Chris Wilmer’s lab (published last week in PLOS ONE) that looks at how human development affects pumas. Like most large carnivores, pumas need vast territories to hunt, find mates and raise young. Pumas living in the San Francisco Bay Area have no such luck. Wilmers, an associate professor of environmental studies at the University of California-Santa Cruz, has been studying the effects of habitat fragmentation on the behavior, ecology and even the physiology of pumas around the Santa Cruz Mountains. He develops cutting-edge GPS collars to track both the location and behavior of his animals.

Fragmented landscapes often pave the way to extinction for wide-ranging large carnivores like pumas, with cascading effects. Freed from the threat of top predators, smaller carnivores like foxes increase in number, driving declines in birds and small mammals. But habitat fragmentation can produce effects similar to extinction because large predators tend to avoid small fragmented parcels. Given the heterogeneous patterns of human developments—with houses and other structures interspersed among natural areas—predicting how animals might respond, and with what consequences, presents a serious challenge.

Read the full article here.

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The Rise of the Tick

Outside Magazine has a nice story on Lyme disease ecology in which they discuss some of the results of our recent PNAS paper.

Some species may even be able to control tick numbers and infection prevalence not by killing the ticks but by killing their favorite hosts. That is the new argument that Taal Levi, a postdoctoral researcher at the Cary Institute, put forward in a 2012 paper in the Proceedings of the National Academy of Sciences. After the morning tick drag, I sat down with Levi at a picnic table outside the institute to hear about the history of foxes.

Foxes were originally very abundant in the eastern United States, where they feasted on small mammals like white-footed mice. But the past few decades have not been good to them. “Fox harvests in the Northeast have declined substantially,” says Levi.

Taal is continuing this work in his postdoc at the Cary Institute in New York.  Read the whole story here.

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Cougars in the mood stay far from humans

From the San Francisco Chronicle, a nice article on our recent PLOS ONE publication.

 Mountain lions, the most fearsome predators in California, lurk closer to suburbia when they are stalking prey or searching out new territory, but the cagey cats steer clear of humans when they are in the mood for romance, according to a UC Santa Cruz study.

If you can’t view the full article on the Chronicle article, here is a pdf version (page 1 , page 2).

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Mountain lion just miles from downtown San Jose photographed by automatic camera

Sometimes I am amazed at how easily mountain lions make it into the news!  Here’s a story in the San Jose Merc about a lion caught on camera at UC’s Blue Oak Reserve in the Hamilton range…

The lion photographed weighs more than 100 pounds. Wilmers said it is a male from 4- to 10-years-old, and it looks healthy. That it wandered into photo range on the outskirts of America’s 10th largest city was bound to happen sooner or later, he said.

“It’s not a surprise to me. There is a lot of great open space there,” Wilmers said. “If anything, it is a testament to the fact that people have been able to protect large open spaces that animals like mountain lions need to be healthy.”

View the full article here.

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Fear and Loathing in Wolf Country

Here’s a great all around article about wolves by Liza Gross, just appearing in QUEST, which draws on some of our research in Yellowstone and Alaska.

Though Ecology 101 tells us that healthy ecosystems need top predators, researchers are just beginning to understand how the presence—and absence—of wolves affects other species.One study found that wolves may buffer the effects of climate change in Yellowstone National Park, where winters have been getting shorter, by leaving their moose and elk leftovers for eagles, ravens, coyotes and other scavengers. Another papersuggests that the absence of wolves may explain the precarious status of the Canada lynx. No wolves means more coyotes—which hunt snowshoe hares, the lynx’s favorite food—and more elk and deer—which eat the shrubby vegetation that sustain and shelter hares. And a 2011 paper in Biological Conservation supports earlier work showing that wolves in Yellowstone influence the behavior of deer and elk, releasing grazing pressure on vegetation, which in turn increases songbird habitat and diversity.

Read the full article here.

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