28 December 2007

headline of the day

Humans Aren't Much Smarter than Dogs

…cognitive scientists gave monkeys and college students a series of very simple tests to determine how quickly and accurately they could add up the number of dots on a screen. On average, the monkeys and students answered in the same amount of time. The students were 94 percent accurate in their answers, while the monkeys were 76 percent accurate. So monkeys are nearly as good as humans at adding dots, even without the benefit of a college education.

What struck me first on contemplating these studies is that cognitive science has taken us in an unforeseen direction. This is a field that promises to study consciousness as if it were a machine, to look at thoughts as electrical impulses and biological structures rather than sublime metaphysics. It would seem, therefore, to run the risk of dehumanizing us, of converting all of our crazy, ambivalent feelings into mere blips on a chart. Instead, what cognitive science has done, at least in these studies, is show us how deeply connected we are to the living creatures around us.

By breaking down our thought processes into their component parts -- pattern recognition, counting -- we are able to see that the building blocks of thought are not unique to Homo sapiens. Dogs and monkeys are doing this shit too.

27 December 2007

escaped tiger kills

[collage by doug millison]

now that they're gone, what do we do?

…from the BBC:

Humans 'drive out large mammals'

A bison (Image: AP)
American bison are one of the species most affected by humans
Almost 80% of the Earth's surface has experienced a sharp fall in the number of large mammals as a result of human activities, a study suggests.

By examining records dating back to AD1500, US researchers found that at least 35% of mammals over 20kg had seen their range cut by more than half.

They said urgent action was needed to protect the animals, which were being hunted or suffering habitat loss.

The findings have been published in the Journal of Mammalogy.

The research, carried out by a team of scientists from Princeton University and conservation group WWF-US, has been described as the first "measurement of human impacts on biodiversity based on the absence of native, large mammals".

"Perhaps the most striking result of our study is that [the] 109 places that still retain the same roster of large mammals as in AD1500 are either small, intensively managed reserved or places of extremes," revealed lead author John Morrison, WWF-US's director of conservation measures.

"Remote areas are either too hot, dry, wet, frozen [or] swampy to support intensive activities."


The researchers compared the current ranges of the world's largest 263 land mammals with their distribution 500 years ago.

We can now pinpoint places where large mammals assemblages still play important roles in terrestrial ecosystems
Eric Dinerstein,
WWF chief scientist

The species that suffered the greatest loss were "habitat generalists", including tigers, leopards, lions, American bison, elk and wolves.

Geographically, Australasia fared best, holding on to 68% of its large mammals. At the other end of the scale, South-East Asia only had 1% of the mega fauna that roamed the region in AD1500.

In their paper, the scientists explained why large mammals were so important for maintaining the ecological equilibrium.

"Large carnivores frequently shape the number, distribution and behaviour of their prey," the researchers wrote.

"Large herbivores function as ecological engineers by changing the structure and species composition of surrounding vegetation.

"Furthermore, both sets of mammals profoundly influence the environment beyond direct species interactions, such as through [the food chain]."

WWF chief scientist Eric Dinerstein said he hoped the findings would help focus conservation efforts.

"We can now pinpoint places where large mammal assemblages still play important roles in terrestrial ecosystems," he explained.

"Through strategic re-introductions - such as returning wolves to Yellowstone - we can restore... places missing one or two species and recover the ecological fabric of these important conservation landscapes."

"what we have here is a failure to communicate"

Trail of blood apparently led escaped tiger to victims

21 December 2007

human researchers come closer to understanding "dolphin"

…from: The Age

While it is already known that dolphins have "signature" whistles that function like a name, little was known about the meaning of the other whistles they make.

By listening in on bottlenose dolphins under water, marine scientist Liz Hawkins found the creatures had specific whistles for certain activities.

When socialising the dolphins tended to make whistles that were flat or rising in tone, but during their travels "sine" whistles that rise and fall were more frequently heard.

The dolphins also made a particular flat-toned whistle when riding the waves created by the research boat, while early work identified a whistle used often by dolphins living off Queensland's Moreton Island when they were on their own.

19 December 2007

what does the bear hair say?

…from Montana State University:

Frozen hair holds secrets of Yellowstone grizzlies

December 17, 2007 -- By Evelyn Boswell, MSU News Service

A curious bear investigates the smell of blood near a wire hair snag. (Photo courtesy of Mark Haroldson).
BOZEMAN -- Locks of hair from more than 400 grizzly bears are stored at Montana State University, waiting to tell the tale of genetic diversity in the Yellowstone Ecosystem.

Ranging from pale blond to almost black, the hair is filed in a chest freezer where the temperature is minus-77.8 degrees. Some of the tufts are almost 25 years old.

The hair will head to Canada in a few months to be analyzed at Wildlife Genetics International in Nelson, British Columbia, said Chuck Schwartz, head of the Interagency Grizzly Bear Study Team based at MSU. The team is monitoring the genetic diversity of the Yellowstone grizzlies over time and wants to know when new DNA appears. The team will also compare the Yellowstone bears with those in the Northern Continental Divide Ecosystem where a similar study has been done.

"An objective of the study is to determine if bears from the Northern Continental Divide Ecosystem migrate to the Yellowstone," Schwartz said.

The Northern Continental Divide Ecosystem includes Glacier National Park, parts of the Blackfeet and Flathead Indian Reservations, parts of five national forests, five wilderness areas and Bureau of Land Management property in northwest Montana. The Yellowstone Ecosystem includes Yellowstone and Grand Teton National Parks, six national forests, and state and private land in portions of Montana, Wyoming and Idaho.

An estimated 550 to 600 grizzlies live in the Yellowstone Ecosystem, about twice what it was 20 years ago, but the population currently lacks diversity, Schwartz said.

"We know it's low," he said. "There are concerns about inbreeding and other issues because we don't have new genes flowing into the system on a regular basis."

Field crews from a variety of federal and state agencies plucked the hair the study team is storing, Schwartz continued. Each lock came from somewhere off the bears' shoulders, but the way it was collected varied. Some of the bears died of natural causes or were killed by humans. Other bears were temporarily unconscious while scientists fit them with radio collars or moved them to another location after they'd gotten into trouble. Some bears left hair behind while crawling underneath barbed wire.

"The vast majority of the time, it is routine," Mark Haroldson said of the collection process. Haroldson is a supervisory wildlife biologist with the Interagency Grizzly Bear Study Team. He has collected bear hair since the late 1980s.

Schwartz said researchers in Idaho can tell him if the hair came from one bear or several. They can tell him the bear's gender and whether the hair came from a bear at all. To answer the tougher questions, Schwartz turns to the Wildlife Genetics International, which routinely analyzes hair from grizzlies, black bears, wolverines and other wildlife in Canada and the United States. The Canadian lab examined the grizzly hair from the Northern Continental Divide Ecosystem. It also analyzes hair collected by MSU graduate students in Yosemite National Park in California and Banff National Park in Alberta, Canada.

Bear hair is tricky because the amount of DNA it contains is so small, said Steven Kalinowski, the students' adviser and a conservation geneticist in MSU's ecology department. Jennifer Weldon, manager of the Canadian lab, said dirty hair can challenge some researchers. So can hair that came from a dead animal and spent so much time in the elements that the DNA degraded.

Schwartz said shafts of the Yellowstone hair will eventually return to MSU so he can conduct other tests and have samples available when new study techniques are developed.

eau de snake

Barbara Clucas/UC Davis photo

…press release from University of California, Davis:

Squirrels Use Snake Scent

December 19, 2007

California ground squirrels and rock squirrels chew up rattlesnake skin and smear it on their fur to mask their scent from predators, according to a new study by researchers at UC Davis.

Barbara Clucas, a graduate student in animal behavior at UC Davis, observed ground squirrels (Spermophilus beecheyi) and rock squirrels (Spermophilus variegates) applying snake scent to themselves by picking up pieces of shed snakeskin, chewing it and then licking their fur. Adult female squirrels and juveniles apply snake scent more often than adult males, which are less vulnerable to predation by snakes, Clucas said.

The scent probably helps to mask the squirrel's own scent, especially when the animals are asleep in their burrows at night, or to persuade a snake that another snake is in the burrow.
The squirrels are not limited to the use of shed snake skins, said Donald Owings, a professor of psychology at UC Davis who is Clucas' adviser and an author on the paper. They also pick up snake odor from soil and other surfaces on which snakes have been resting, and use that to apply scent. Other rodents have been observed using similar behavior.

Snake-scent application is one of a remarkable package of defenses that squirrels use against rattlesnakes, Owings said. In earlier work, Owings' lab has found that squirrels can: heat up their tails to send a warning signal to rattlesnakes, which can "see" in the infrared; assess how dangerous a particular snake is, based on the sound of its rattle; and display assertive behavior against snakes to deter attacks. In addition, work by Owings' colleague, psychology professor Richard Coss, has demonstrated that these squirrels have evolved resistance to snake venom.

"It's a nice example of the opportunism of animals," Owings said. "They're turning the tables on the snake."

The other authors on the paper, which was published Nov. 28 in the journal Animal Behavior, are Matthew Rowe, Sam Houston State University, Texas, and Patricia Arrowood at New Mexico State University. The work was funded by the National Science Foundation and the Animal Behavior Society.

mental monkey math

…press release from Duke University:

Monkeys Can Perform Mental Addition

DURHAM, N.C.--Researchers at Duke University have demonstrated that monkeys have the ability to perform mental addition. In fact, monkeys performed about as well as college students given the same test.

The findings shed light on the shared evolutionary origins of arithmetic ability in humans and non-human animals, according to Assistant Professor Elizabeth Brannon, Ph.D. and Jessica Cantlon, Ph.D., of the Duke Center for Cognitive Neuroscience.

Current evidence has shown that both humans and animals have the ability to mentally represent and compare numbers. For instance, animals, infants and adults can discriminate between four objects and eight objects. However, until now it was unclear whether animals could perform mental arithmetic.

"We know that animals can recognize quantities, but there is less evidence for their ability to carry out explicit mathematical tasks, such as addition," said graduate student Jessica Cantlon. "Our study shows that they can."

Cantlon and Brannon set up an experiment in which macaque monkeys were placed in front of a computer touch screen displaying a variable number of dots. Those dots were then removed and a new screen appeared with a different number of dots. A third screen then appeared displaying two boxes; one containing the sum of the first two sets of dots and one containing a different number. The monkeys were rewarded for touching the box containing the correct sum of the sets.

The same test was presented to college students, who were asked to choose the correct sum without counting the individual dots. While the college students were correct 94 percent the time and the monkeys 76 percent, the average response time for both monkeys and humans was about one second.

Interestingly, both the monkeys' and the college students' performance worsened when the two choice boxes were close in number.

"If the correct sum was 11 and the box with the incorrect number held 12 dots, both monkeys and the college students took longer to answer and had more errors. We call this the ratio effect," explained Cantlon. "What's remarkable is that both species suffered from the ratio effect at virtually the same rate."

That monkeys and humans share the ability to add suggests that basic arithmetic may be part of our shared evolutionary past.

Humans have added language and writing to their repertoire, which undoubtedly changes the way we represent numbers. "Much of adult humans' mathematical capacity lies in their ability to represent numerical concepts using symbolic language. A monkey can't tell the difference between 2000 and 2001 objects, for instance. However, our work has shown that both humans and monkeys can mentally manipulate representations of number to generate approximate sums of individual objects," says Brannon.

The study was published in the December 2007 issue of the journal PLoS Biology.

[drawing by morris armstrong, jr.]