Wolf Encounter Leaves Cows With Post-Traumatic Stress
CORVALLIS, Ore. (AP) — Cows that survive a wolf encounter reportedly suffer symptoms similar to post-traumatic stress disorder.
A study by Oregon State University found the stress increases the number of low-weight calves and the likelihood of getting sick. Weight loss translates into a financial loss for ranchers.
Researchers induced wolf stress by putting cows in a pen scented with an odor associated with wolves while playing recorded wolf howls on a stereo.
The study was conducted by Oregon State University animal scientists Reinaldo Cooke and David Bohnert. The study was funded by the Oregon Beef Council and published in the Journal of Animal Science.
Yosemite Bears Turn Health Nuts With Junk Food Off Menu
LOS ANGELES (Reuters) – Bears in Yosemite National Park in California have adopted the wildlife version of a health food diet after increased safety measures largely blocked them from scavenging for food in campgrounds over the last 15 years, a study showed on Tuesday.
An estimated 350 to 400 black bears roam Yosemite, one of the most popular U.S. tourist destinations. Interactions between the park’s bears and people reached a record level in 1998 as the animals raided campgrounds and broke into cars in search of groceries and leftovers, according to Yosemite spokesman Scott Gediman.
After recording 1,584 human-bear interactions that year, the park adopted a policy in 1999 that included placing bear-resistant food storage containers at campgrounds and cracking down more forcefully on people leaving out items like chips or bread, Gediman said.
The initiative seems to have paid off in the park, where waterfalls and sequoia trees draw tourists from around the globe. A research paper in this month’s edition of the journal Frontiers in Ecology and the Environment found a 63 percent drop in the proportion of human food in the diet of Yosemite’s bears.
The animals now eat the same amount of human food as they did in 1915, when the park had a few thousand visitors annually, compared to the current count of 4 million people a year, the study suggested. The number of bear-human interactions has also dropped dramatically, to just 155 in 2012, Gediman said.
That comes as the park’s approach to wildlife management has evolved dramatically since the park was created in 1890, as rangers began recognizing the need to keep bears away from people.
For decades until the mid-1960s, rangers would feed bears in open areas and allow visitors to sit in bleachers to watch the spectacle, Gediman said. “It was entertainment,” he said.
Jack Hopkins, a research fellow at the University of California, Santa Cruz, who led the study, said he traced how much human food bears were consuming by stringing up barbed wire in the park to snag hair from the animals.
The study analyzed the hair, comparing it to bones from bears that inhabited the park around 1915 and in later decades. Researchers looked for certain types of nitrogen and carbon isotopes in the hair and bones to determine how much human food they were consuming, since those isotopes are indicative of a human-like diet.
The analysis showed Yosemite bears were eating 63 percent less human food in the period after the new policies were put in place than between 1975 and 1985, a period during which some bears were consuming more human food than at any other time previously recorded.
Among the many downsides of human food consumption for bears is that they may suffer from rotting teeth because of the high sugar content in the pilfered chow, Hopkins said. Furthermore, a bear hooked on human food will keep coming back, putting both humans and bears at risk, he said.
“One of the big things is to put more focus into prevention management,” Hopkins said. “Take care of the problem at its root, which is removing human food from the landscape and keeping it in a place where animals cannot get it.”
As Yosemite officials have succeeded in keeping human food away from bears, rangers are now in the position of having to kill only one or two of the animals a year compared to seven or eight annually in the 1990s, Gediman said.
Portland Elephants Like Golf Course Sand
PORTLAND, Ore. (AP) — Not all sand is created equal. Just ask Lily, the Oregon Zoo’s youngest elephant.
On a recent morning, the one-year-old Asian elephant, all 1,400 pounds of her, dug her feet into the smooth grit as she poked around in the rain for tree limbs, bamboo and other food.
Children, even pachyderms, love a sandbox. And this one, a just-completed chunk of the new $57 million Elephant Lands exhibit, is elephant-sized.
The special sand that covers the new outdoor Encounter Habitat, on the south end of what will be Elephant Lands, was found after a year of testing to find the right mix of cushion and porosity.
The deciding factor came from the elephant pack, said Bob Lee, the zoo’s elephant curator. The elephants were given chances to try different sands before the zoo picked the kind that was just right.
And where did the just-right sand come from? It was dredged from the Columbia River by CalPortland’s aggregate plant in Vancouver.
The sediment in the elephant exhibit — which will use 15,000 cubic yards of sand at 4 feet deep — is the same kind used on golf courses, known as USGA topdressing. It’s not as coarse as other sands and drains exceptionally well.
Project engineer Wayne Starkey visited the Vancouver sand facility in the fall and took a look at available varieties. He found that finer masonry sand held more water than was acceptable. A rougher sand drained well, but when it was tested with the elephants, it didn’t seem to draw them in the way the USGA topdressing did. During a trial period, he said, a mound of the USGA topdressing got more attention from the elephants; Lily and her big brother Samudra even used it to play king of the hill.
“It’s really about letting the elephants make decisions for themselves,” Lee said.
Lee said he and the Portland Zoo went to such efforts to design the best possible habitat, even sending staff to Ireland’s Dublin Zoo to find inspiration, because, after 15 years of caring for these elephants, the health of the herd is of prime importance to him.
“They are like family,” he said.
Elephants weigh thousands of pounds, so their relatively small feet need cushioning to ensure they stay healthy and comfortable.
In the wild, Asian elephants roam freely over all sorts of terrain. But when elephants became popular zoo attractions in North America, many zoos housed the giant animals in yards and barns covered with concrete. The concrete is easy to clean but can cause problems such as arthritis and degenerative bone ailments.
The Oregon Zoo last updated the elephants’ home at the turn of the century by adding rubberized flooring indoors to replace the concrete that had been there for decades.
“Rubber is better than concrete,” Lee said. “But we thought, ‘What can we do that’s better than that?’”
Money for the expansion came from a $125 million bond passed by Portland Metro voters in 2008.
Though zoo staff are happy the Elephant Lands project is finally coming to fruition after years of planning, Lee said it’s the enthusiastic reaction from the animals that gives him the most joy.
“To watch the elephants run around and enjoy it has been the biggest reward of all,” Lee said.