October 24, 2006, 7:11 PM CT
Trotting With Emus To Walk With Dinosaurs
One way to make sense of 165-million-year-old dino tracks may be to hang out with emus, say paleontologists studying thousands of dinosaur footprints at the Red Gulch Dinosaur Tracksite in northern Wyoming. Because they are about the same size, walk on two legs and have similar feet, emus turn out to be the best modern version of the enigmatic reptiles that once trotted along a long-lost coastline in the Middle Jurassic.
"We don't have any documented dinosaur bones and teeth from that period in North America, except for some very scrappy material from Mexico," said Brent Breithaupt, curator and director of the University of Wyoming's Geological Museum in Laramie, Wyo. That makes it very hard to connect the tracks to a particular dinosaur. And of course, "We unfortunately can't go out and see walking dinosaurs today. Or can we?".
After scouring the dinosaur fossil record in other parts of the world and deciding that a human-sized, meat-eating dinosaur (theropod) fit the bill for the tracks at Red Gulch, Breithaupt and colleagues and students did something unusual. Instead of speculating about what the dinosaurs were doing, they went hunting for a modern analog animal they could study to help decipher the tracks.
Large flightless birds are the most logical choice and are, along with all birds today, believed to be descended from dinosaurs. But not all of those alive today are good choices or easy to work with. Ostriches are two-toed and have an attitude problem, so that ruled them out, says Breithaupt. Rheas have three toes, but are "like working with a bunch of kindergarteners on too much sugar," he said.........
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October 24, 2006, 7:04 PM CT
Cougar Predation Key To Ecosystem Health
The general disappearance of cougars from a portion of Zion National Park in the past 70 years has allowed deer populations to dramatically increase, leading to severe ecological damage, loss of cottonwood trees, eroding streambanks, and declining biodiversity.
This "trophic cascade" of environmental degradation, all associated with the decline of a major predator, has been shown in a new study to affect a broad range of terrestrial and aquatic species, as per researchers from Oregon State University.
The research was just reported in the journal Biological Conservation and, like recent studies outlining similar ecological ripple effects following the disappearance of wolves in the American West may cause land managers to reconsider the importance of predatory species in how ecosystems function.
The findings are consistent, scientists say, with predictions made more than half a century ago by the famed naturalist Aldo Leopold, often considered the father of wildlife ecology.
"When park development caused cougar to begin leaving Zion Canyon in the 1930s, it allowed much higher levels of deer browsing," said Robert Beschta, an OSU professor emeritus of forest hydrology. "That set in motion a long cascade of changes that resulted in the loss of most cottonwoods along the streambanks and heavy bank erosion".........
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October 17, 2006, 9:58 PM CT
First New Mammal Found In Europe In 100 Years
Meet the Cypriot mouse-the first new mammal species to be discovered in Europe in more than a century.
The researchers who announced the find yesterday think the previously unknown creature is confined to the Mediterranean island of Cyprus (map of Cyprus).
The mouse differs from other European mice by having a bigger head, bigger ears, bigger eyes, and bigger teeth, says its discoverer, French zoologist Thomas Cucchi.
Cucchi, who is based at Durham University in England, noticed the small gray rodent while studying mice teeth from the Stone Age and comparing them with those of species still living on Cyprus. Genetic tests later confirmed it as a new species, now named Mus cypriacus.........
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October 17, 2006, 9:41 PM CT
New Research To Cut Animal Testing
Scientists at The University of Manchester have been awarded £130,000 to develop new techniques to reduce the need for animals in drug testing.
Current checks to establish whether a new drug is carcinogenic can be inconclusive and require further testing on live animals to establish whether they are harmful or not.
Dr Richard Walmsley and his colleagues at the University spin-out company he founded, Gentronix, have developed techniques using cultured human cells to more effectively weed out cancer-causing compounds.
"The current pre-animal tests that are used are highly sensitive and so most carcinogens are identified," said Dr Walmsley, who is based in the Faculty of Life Sciences.
"Unfortunately, such tests have poor specificity and a lot of safe compounds are also wrongly identified as potential carcinogens. This means that animal testing is still carried out, in case such compounds turn out to be safe.
"The testing process developed at Gentronix has proven very reliable at telling us whether a drug will cause cancer but some chemicals, called promutagens, only become carcinogenic once they have passed through the body's liver.
"This grant will help us develop new non-animal experiments to identify these other toxic compounds and so reduce the need for animal testing".........
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October 16, 2006, 9:42 PM CT
Tiger population declining
Experts say that illegal wildlife trade ranks among the most lucrative rackets in the world -- in the range of such enterprises as narcotics and arms smuggling. The international police organization Interpol estimates the annual turnover in wildlife trade is over $6 billion.
Tigers (Panthera tigris) are mammals of the Felidae family and one of four "big cats" in the Panthera genus. They are superpredators and the largest and most powerful living cat species in the world[2][3]. The Royal Bengal Tiger is the most common subspecies of tiger, constituting approximately 80% of the entire tiger population, and is found in the Indian subcontinent. The tiger's beautiful blend of grace and ferocity led the legendary author and conservationist, Jim Corbett to remark - "The Tiger is a large hearted gentleman with boundless courage".
Most tigers live in forests or grasslands, for which their camouflage is ideally suited, and where it is easy to hunt prey that is faster or more agile. Among the big cats, only the tiger and jaguar are strong swimmers; tigers are often found bathing in ponds, lakes, and rivers. Tigers hunt alone and eat primarily medium to large sized herbivores such as deer, wild pigs, gaur and water buffalo. However, they also take smaller prey on occasion.........
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October 15, 2006, 8:17 PM CT
Giant Pandas Can See Color
They may be black and white, but new research at the Georgia Institute of Technology and Zoo Atlanta shows that giant pandas can see in color. Graduate researcher Angela Kelling tested the ability of two Zoo Atlanta pandas, Yang Yang and Lun Lun, to see color and observed that both pandas were able to discriminate between colors and various shades of gray. The research is reported in the psychology journal Learning and Behavior, volume 34 issue 2.
"My study shows that giant pandas have some sort of color vision," said Kelling, graduate student in Georgia Tech's Center for Conservation Behavior in the School of Psychology. "Most likely, their vision is dichromatic, since that seems to be the trend for carnivores".
Vision is not a well-studied aspect of bears, including the giant pandas. It has long been thought that bears have poor vision, perhaps, Kelling said, because they have such excellent senses of smell and hearing. Some experts have thought that bears must have some sort of color vision as it would help them in identifying edible plants from the inedible ones, eventhough there's been little experimental evidence of this. However, one experiment on black bears found some evidence that bears could tell blue from gray and green from gray. Kelling used this study's design as the basis to test color vision in Zoo Atlanta's giant pandas.........
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October 12, 2006, 9:04 PM CT
Health of Florida's Coral Reef
NASA satellite data was used to help monitor the health of Florida's coral reef as part of a field research effort completed this August and September.
The project was the first comprehensive assessment of the resiliency of reefs along the National Oceanic and Atmospheric Administration's (NOAA) Florida Keys National Marine Sanctuary. The sanctuary is administered by NOAA in partnership with the Florida Department of Environmental Protection. The Sanctuary stretches from the Dry Tortugas to the southern boundary of Biscayne National Park. The area north of there has reefs and is part of the Florida Reef Resilience Program, but lies outside the sanctuary. Researchers are trying to determine why some reefs are resilient to environmental changes and impacts. The work may also identify ways to care for reefs worldwide.
At nearly 175 sites, scuba divers recorded the number and species of coral and the extent of bleaching -- corals turn white when tiny algae that live inside them die. Bleaching is a symptom of coral stress, which can be caused by high water temperatures, other environmental stresses, or disease. The project was part of the Florida Reef Resiliency Program, funded by the state of Florida and The Nature Conservancy. It involved volunteers and scientists from several agencies, organizations and universities, including the University of South Florida.........
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October 12, 2006, 5:15 AM CT
In Wake Of Horse Slaughter Bill
The American Horse Slaughter Prevention Act, making its way from the U.S. House to the Senate, could leave thousands of horses with no final resting ground.
Composting may be an environmentally friendly option that fits in the "circle of life" frame of mind and may be less emotional, two area scientists said.
On Sept. 7 the House approved the Act, which bans the slaughter of horses for human consumption by a vote of 263-146. The Senate has yet to schedule the issue for consideration.
Approximately 90,000 horses, or 1 percent of the U.S. horse population, is slaughtered annually, said Dr. Lance Baker, West Texas A&M University associate professor of animal science.
"If they don't go to slaughter, they will have to go somewhere else," Baker said.
The options for dealing with a carcass are burial, rendering, landfill disposal, incineration, composting or bio-digesting, he said. A number of of these are costly, and a horse owner often has to pay to put the horse down and for its disposal, instead of getting money for the animal.
Large-carcass composting is a growing and accepted practice among feedyards and dairies, said Dr. Brent Auvermann, a Texas Agricultural Experiment Station agricultural engineer who has researched the process for about five years.........
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October 11, 2006, 5:13 AM CT
Uncovering Mysteries Of Memory
Image courtesy of Cornell
Keeping track of one set of keys is difficult enough, but imagine having to remember the locations of thousands of sets of keys. Do you use landmarks to remember where you put them? Do you have a mental map of their locations?
Researchers at the University of New Hampshire hope to learn more about memory and its evolution by studying the Clark's nutcracker, a bird with a especially challenging task: remembering where it buried its supply of food for winter in a 15-mile area. Like a number of animals preparing for the winter, every fall the Clark's nutcracker spends several weeks gathering food stores. What makes it unique is that it harvests more than 30,000 pine nuts, buries them in up to 5,000 caches, and then relies almost solely on its memory of where those caches are located to survive through winter.
Brett Gibson, a scientist studying animal behavior, began studying Clark's nutcrackers in graduate school and is continuing his research into memory and the behavior of nutcrackers as an assistant professor in UNH's psychology department.
"Nutcrackers are almost exclusively dependent upon cache recovery for their survival so if they don't remember where they've made those caches, then they are in trouble," Gibson says. "During winter, their cache locations are covered with snow so a number of of the small local features in the landscape during fall are no longer available to them. What's clear is that they are using spatial memory to recover these caches. They are remembering these caches based on landmarks and other features of the terrain."........
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October 11, 2006, 5:02 AM CT
Water Temperatures, Pollution Have Oysters In Hot Water
Oysters exposed to high water temperatures and a common heavy metal are unable to obtain sufficient oxygen and convert it to cellular energy, as per a new study presented at The American Physiological Society conference, Comparative Physiology 2006.
The study showed how cadmium, a heavy metal, reduces the oyster's tolerance of warmer water temperatures and makes it more vulnerable during the summer when water temperatures rise. Half of the oysters exposed to the pollutant in 28 C (82 F) water died within 20 days, said lead researcher Gisela Lannig. Oysters exposed to cadmium at lower temperatures showed much lower mortality rate, suggesting that the combination of high temperature and cadmium is more stressful than each of these conditions alone, she said.
The study "Temperature tolerance in the oyster, Crassostrea virginica, is affected by cadmium," was carried out by Lannig, of the Alfred Wegener Institute for Polar & Marine Research, Bremerhaven, Gera number of, and Jason Flores and Inna Sokolova, of the University of North Carolina at Charlotte. The work was done in North Carolina. The scientists presented the study October 10 during a poster session at Comparative Biology 2006: Integrating Diversity in Virginia Beach.
Oyster population decimated........
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