RIVERSIDE, Calif. – A new study shows that the desert tortoise, thought to be one species for the past 150 years, now includes two separate and distinct species, based on DNA evidence and biological and geographical distinctions.
This genetic evidence confirms previous suspicions, based on life history analysis, that tortoises west and east of the Colorado River are two separate species. (more…)
Japan’s recent magnitude 9.0 earthquake, which triggered a devastating tsunami, relieved stress along part of the quake fault but also has contributed to the build up of stress in other areas, putting some of the country at risk for up to years of sizeable aftershocks and perhaps new main shocks, scientists say.
After studying data from Japan’s extensive seismic network, researchers from the Woods Hole Oceanographic Institution (WHOI), Kyoto University and the U.S. Geological Survey (USGS) have identified several areas at risk from the quake, Japan’s largest ever, which already has triggered a large number of aftershocks. (more…)
LAUREL, Md. — Imagine spending your time feeding, nurturing, and teaching the daily tasks of survival to a baby who could never know your true identity. (more…)
This Black-capped Chickadee, captured in Anchorage, Alaska, demonstrates an overgrown beak characteristic of avian keratin disorder. Beak deformities in this species were first observed in the late 1990s and biologists have since documented more than 2,100 affected individuals in Alaska. Image credit: U.S. Geological Survey
ANCHORAGE, Alaska – The highest rate of beak abnormalities ever recorded in wild bird populations is being seen in a number of species in the Northwest and Alaska, and scientists to this point have not been able to isolate the cause.
Black-capped Chickadees, Northwestern Crows, and other birds are being impacted by the problem, which affects their ability to feed and clean themselves and could signal a growing environmental health problem.
In birds affected by what scientists have termed “avian keratin disorder,” the keratin layer of the beak becomes overgrown, resulting in noticeably elongated and often crossed beaks, sometimes accompanied by abnormal skin, legs, feet, claws and feathers. Biologists with the U.S. Geological Survey’s Alaska Science Center published their findings in this month’s issue of The Auk, a Quarterly Journal of Ornithology.
“The prevalence of these strange deformities is more than ten times what is normally expected in a wild bird population,” said research biologist Colleen Handel with the USGS, “We have seen effects not only on the birds’ survival rates, but also on their ability to reproduce and raise young. We are particularly concerned because we have not yet been able to determine the cause, despite testing for the most likely culprits.” (more…)
WASHINGTON — Glaciers that detach from the seafloor and begin floating create larger icebergs than glaciers that stay on the sea floor, researchers have found. Floating glaciers also produce icebergs more erratically.
