Tag Archives: North America

Imperiled Mussels May be Further Harmed by Climate Change

By Guest PostDecember 5, 2013Environment, Natureaquatic food web, climate change, danger of extinction, freshwater mussels, freshwater science, global climate change, good water, habitat alteration, indicator, native mussel populations, North America, potential effect, rising water temperatures, river studies center, sediment quality, species, teresa newton, U.S. Geological Survey, us river, usgs scientists, washboard mussels

Rising water temperatures as a result of climate change may harm already endangered or threatened native freshwater mussels in North America, according to a new U.S. Geological Survey report.

During laboratory tests, USGS scientists and partners found that the heart and growth rates of some species of young freshwater mussels declined as a result of elevated water temperatures, and many died. Freshwater mussels have been compared to the “canary in the coal mine” in that they are indicators of good water and sediment quality in U.S. rivers. They are also important in the aquatic food web, filter large amounts of water and suspended particles, and serve as food for other organisms. The study is published in the December issue of the journal Freshwater Science. (more…)

‘Tiger stripes’ underneath Antarctic glaciers slow the flow

By Guest PostNovember 30, 2013Environmentantarctic glaciers, antarctic ice, bed of rock, british antarctic survey, climate change, douglas macayeal, Europe, flow of glaciers, friction zones, massive antarctic glaciers, mathematical modeling, North America, olga sergienko, pattern, pine island glacier, princeton university, richard hindmarsh, satellite measurements, sea-level rise, sediment, thwaites glacier, tiger stripes, university of chicago, warming climate, west antarctica

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…)

Colossal New Predatory Dino Terrorized Early Tyrannosaurs

By Guest PostNovember 24, 2013Nature, Scienceacrocanthosaurus, carcharodontosaur, carnivorous dinosaur, cedar mountain formation, early tyrannosaurs, largest ever discovered, late cretaceous period, lindsay zanno, meeker family, neovenatoridae, new predatory dino, new species, North America, north Carolina, paleontologist, peter makovicky, siats meekerorum, skeleton, small bodied tyrannosaurs, state university, tyrannosaurus rex, utah, ute tribal legend

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…)

Dogs likely originated in Europe more than 18,000 years ago, UCLA biologists report

By Guest PostNovember 16, 2013Nature, Scienceancient dog fossil, ancient hunter, carnivore, co evolutionary process, coyotes, daniel greenfield, dog, dog like animals, dogs from europe, domestic dogs, druid peak, east asia, Europe, european hunter, european wolves, evolutionary biology, finland, fossil, genetic analysis, genetic data, illinois, klaus koepfli, koster archaeological site, late pleistocene, middle east, middle east origin, migration, mitochondrial dna, modern dogs, North America, olaf thalmann, old world, origin, proximity to humans, robert wayne, species, two wolves, ucla biologist, university of turku, western russia, wolf like animals, yellowstone national park

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…)

The People’s Choice: Americans Would Pay to Help Monarch Butterflies

By Guest PostOctober 31, 2013Natureamericans would pay, california, caterpillars, corn, economic valuation survey, genetically modified, herbicide tolerant crops, iconic butterfly, jay diffendorfer, karen oberhauser, Mexico, migratory species, monarch butterflies, North America, pollinators, soybeans, united states, university of minnesota, us households, usgs scientist

Americans place high value on butterfly royalty. A recent study suggests they are willing to support monarch butterfly conservation at high levels, up to about 6 ½ billion dollars if extrapolated to all U.S. households.

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…)

How red crabs on Christmas Island speak for the tropics

By Guest PostOctober 12, 2013Environment, Natureallison shaw, australia national university, christmas island, climate pattern, cocos, crabs larvae, earth, ecosystem, el niño, erratic rainfall, fluctuations in rainfall, forest dynamics, indian ocean, kathryn kelly, keeling islands, migration data, migratory animals, next generation, North America, ocean, princeton university, red crabs, tropical zones, tropics, university of minnesota, university of washington

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…)

Tropical forest carbon absorption may hinge on an odd couple

By Guest PostOctober 7, 2013Environmentabsorb, atmosphere, carbo loading bacteria, carbon absorption, carbon dioxide, carbon sink, component of biodiversity, david medvigy, dylan craven, Europe, excess nitrogen, human activities, infectious bacteria, jefferson hall, journal nature, lars hedin, legume family, michiel van breugel, models, nitrogen, nitrogen fixation, nitrogen fixing trees, non legume trees, North America, photosynthesis, princeton university, rhizobia, root nodules, sarah batterman, stri, tropical forest, united states

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…)

Effects of Climate Change on West Nile Virus

By Guest PostSeptember 11, 2013Environment, Healthandrew comrie, brain, canada, cdc, changes in climate, climate change, climate change models, climate-driven, cory morin, culex quinquefasciatus, effect, encephalitis, immune response, infectious cycle, inflammation, meningitis, mosquito population model, mosquito populations, North America, precipitation, southern us, species, temperature, united states, university of arizona, virus carrying mosquitoes, west nile vector, west nile virus

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…)