Narrow stripes of dirt and rock beneath massive Antarctic glaciers create friction zones that slow the flow of ice toward the sea, researchers at Princeton University and the British Antarctic Survey have found. Understanding how these high-friction regions form and subside could help researchers understand how the flow of these glaciers responds to a warming climate.
Just as no-slip strips on flooring prevent people from slipping on a wet floor, these ribs or “tiger stripes” — named in reference to Princeton’s tiger mascot — provide friction that hinders the glaciers from slipping along the underlying bed of rock and sediment, the researchers report online in the journal Science. (more…)
A new species of carnivorous dinosaur – one of the three largest ever discovered in North America – lived alongside and competed with small-bodied tyrannosaurs 98 million years ago. This newly discovered species, Siats meekerorum, (pronounced see-atch) was the apex predator of its time, and kept tyrannosaurs from assuming top predator roles for millions of years.
Named after a cannibalistic man-eating monster from Ute tribal legend, Siats is a species of carcharodontosaur, a group of giant meat-eaters that includes some of the largest predatory dinosaurs ever discovered. The only other carcharodontosaur known from North America is Acrocanthosaurus, which roamed eastern North America more than 10 million years earlier. Siats is only the second carcharodontosaur ever discovered in North America; Acrocanthosaurus, discovered in 1950, was the first. (more…)
Wolves likely were domesticated by European hunter–gatherers more than 18,000 years ago and gradually evolved into dogs that became household pets, UCLA life scientists report.
“We found that instead of recent wolves being closest to domestic dogs, ancient European wolves were directly related to them,” said Robert Wayne, a professor of ecology and evolutionary biology in UCLA’s College of Letters and Science and senior author of the research. “This brings the genetic record into agreement with the archaeological record. Europe is where the oldest dogs are found.” (more…)
If even a small percentage of the population acted upon this reported willingness, the cumulative effort would likely translate into a large, untapped potential for conservation of the iconic butterfly. (more…)
Each year, the land-dwelling Christmas Island red crab takes an arduous and shockingly precise journey from its earthen burrow to the shores of the Indian Ocean where weeks of mating and egg laying await.
Native to the Australian territories of Christmas Island and the Cocos (Keeling) Islands, millions of the crabs start rolling across the island roads and landscape in crimson waves when the November rains begin. After a two-week scuttle to the sea, the male crab sets up and defends a mating burrow for himself and a female of his kind, the place where she will incubate their clutch for another two weeks. Before the morning of the high tide that precedes the December new moon, the females must emerge to release their millions of eggs into the ocean. A month later, the next generation of crabs comes ashore. (more…)
A unique housing arrangement between a specific group of tree species and a carbo-loading bacteria may determine how well tropical forests can absorb carbon dioxide from the atmosphere, according to a Princeton University-based study. The findings suggest that the role of tropical forests in offsetting the atmospheric buildup of carbon from fossil fuels depends on tree diversity, particularly in forests recovering from exploitation.
Tropical forests thrive on natural nitrogen fertilizer pumped into the soil by trees in the legume family, a diverse group that includes beans and peas, the researchers report in the journal Nature. The researchers studied second-growth forests in Panama that had been used for agriculture five to 300 years ago. The presence of legume trees ensured rapid forest growth in the first 12 years of recovery and thus a substantial carbon “sink,” or carbon-storage capacity. Tracts of land that were pasture only 12 years before had already accumulated as much as 40 percent of the carbon found in fully mature forests. Legumes contributed more than half of the nitrogen needed to make that happen, the researchers reported. (more…)
A study projects how climate change may affect virus-carrying mosquitoes across the southern U.S. Changes are expected to vary with region, and the southern states should see a trend toward longer seasons of mosquito activity and smaller midsummer mosquito populations
The varied influence of climate change on temperature and precipitation may have an equally wide-ranging effect on the spread of West Nile virus, suggesting that public health efforts to control the virus will need to take a local rather than global perspective, according to a study published this week in the scientific journal Proceedings of the National Academy of Sciences. (more…)
Outdoor recreationists should take precautions to avoid problems with bears in southern Missouri
COLUMBIA, Mo. — For nearly a century, the only bears known to reside in Missouri were on the state flag or in captivity. Unregulated hunting and habitat loss had wiped out most black bears in Missouri, Arkansas and Oklahoma by the 1920s. Now, thanks to a reintroduction program in Arkansas during the 50s and 60s, hundreds of bears amble through the forests of southern Missouri, according to a joint study by University of Missouri, Mississippi State University, and Missouri Department of Conservation biologists, who warn that although the bear population is still small, outdoor recreationists and homeowners should take precautions in the Ozark forest to avoid attracting bears.
“Black bears normally do not attack humans, but they will ransack picnic baskets, tear through garbage bags or even enter buildings looking for food,” said Lori Eggert, associate professor of biological sciences in MU’s College of Arts and Science. “Although some Missourians may be concerned, the return of black bears to Missouri is actually a good sign. It means parts of the state’s forests are returning to a healthy biological balance after nearly two centuries of intensive logging and exploitation.” (more…)
