U researchers map emperor penguin colonies by satellite
Emperor penguins may be icons of the Antarctic, but they aren’t immune to disturbances in their environment.
As climatic and other changes unfold, emperors may dwindle in numbers. But how to tell, when researchers can’t access all the emperor colonies dotting the Antarctic ice shelves and count heads every year?
Satellites, that’s how. (more…)
AUSTIN, Texas — Seed size is controlled by small RNA molecules inherited from a plant’s mother, a discovery from scientists at The University of Texas at Austin that has implications for agriculture and understanding plant evolution.
“Crop seeds provide nearly 70 to 80 percent of calories and 60 to 70 percent of all proteins consumed by the human population,” said Z. Jeff Chen, the D.J. Sibley Centennial Professor in Plant Molecular Genetics at The University of Texas at Austin. “Seed production is obviously very important for agriculture and plant evolution.” (more…)
Bat wings are like hands: meaty, bony and full of joints. A new Brown University study finds that bats take advantage of their flexibility by folding in their wings on the upstroke to save inertial energy. The research suggests that engineers looking at flapping flight should account for wing mass and consider a folding design.
PROVIDENCE, R.I. [Brown University] — Whether people are building a flying machine or nature is evolving one, there is pressure to optimize efficiency. A new analysis by biologists, physicists, and engineers at Brown University reveals the subtle but important degree to which that pressure has literally shaped the flapping wings of bats.
The team’s observations and calculations show that by flexing their wings inward to their bodies on the upstroke, bats use only 65 percent of the inertial energy they would expend if they kept their wings fully outstretched. Unlike insects, bats have heavy, muscular wings with hand-like bendable joints. The study suggests that they use their flexibility to compensate for that mass. (more…)
ANN ARBOR, Mich.— When tropical marine cone snails sink their harpoon-like teeth into their prey, they inject paralyzing venoms made from a potent mix of more than 100 different neurotoxins.
Biologists have known for more than a decade that the genes which provide the recipes for cone snail toxins are among the fastest-evolving genes in the animal kingdom, enabling these predatory gastropods to constantly refine their venoms to more precisely target the neuromuscular systems of their prey. (more…)
HONOLULU – A species of lizard is now extinct from the Hawaiian Islands, making it the latest native vertebrate species to become extirpated from this tropical archipelago.
The copper striped blue-tailed skink (Emoia impar) — a sleek lizard with smooth, polished scales and a long, sky-blue tail — was last confirmed in the Na’Pali coast of Kauai in the 1960s. But repeated field surveys on Kauai, Oahu, Maui and Hawai’i islands from 1988 to 2008 have yielded no sightings or specimens. (more…)
Mesquite trees and woody shrubs are better adapted than grasslands to a Southwestern climate predicted to shift toward higher temperatures and greater variability in rainfall, UA ecologists have discovered.
As the desert Southwest becomes hotter and drier, semi-arid grasslands are slowly being replaced by a landscape dominated by mesquite trees, such as Prosopis velutina, and other woody shrubs, a team of University of Arizona researchers has found.
In a “leaf-to-landscape” approach, the team combined physiological experiments on individual plants and measurements across entire ecosystems to quantify how well grasslands, compared to mesquite trees and woody shrubs, cope with heat and water stress across seasonal precipitation periods. (more…)
*Loss of milkweed in Midwestern farm fields harms butterflies, a study shows*
If you’re a gardener, milkweed may not be at the top of your list.
But if you love Minnesota’s state insect—the monarch butterfly—maybe it should be.
Monarchs lay their eggs on milkweed, but the plant is disappearing from what used to be a prime reservoir: Midwestern farm fields. A new study by University of Minnesota monarch expert Karen Oberhauser and her Iowa State colleague John Pleasants ties a decade-long decline in monarch populations to the loss of milkweed from the corn and soybean fields that blanket the region. (more…)
Conventional wisdom holds that during the Mesozoic Era, mammals were small creatures that held on at life’s edges. But at least one mammal group, rodent-like creatures called multituberculates, actually flourished during the last 20 million years of the dinosaurs’ reign and survived their extinction 66 million years ago.
New research led by a University of Washington paleontologist suggests that the multituberculates did so well in part because they developed numerous tubercles (bumps, or cusps) on their back teeth that allowed them to feed largely on angiosperms, flowering plants that were just becoming commonplace. (more…)
