At times during the past 10,000 years, cottontails and hares reproduced like rabbits and their numbers surged when the El Niño weather pattern drenched the Pacific Coast with rain, according to a University of Utah analysis of 3,463 bunny bones. The study of ancient rabbit populations at a Baja California site may help scientists better understand how mammals that range from the coast to the interior will respond to climate change, says anthropology doctoral student Isaac Hart. He is first author of the study to be published in the July issue of the journal Quaternary Research.
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More than 200,000 people flooded the U.S. Forest Service with comments over the last month calling for the agency to reject a plan for roads and infrastructure that would enable construction of a mega-development on the Grand Canyon’s doorstep.
The proposed roads, sewers and other utilities would pave the way for a multinational developer to transform the 580-resident community of Tusayan, Ariz., from a small, quiet tourist town into a sprawling complex of high-end homes, retail stores and restaurants only a mile from the Grand Canyon National Park boundary. The development threatens groundwater that feeds the Grand Canyon’s creeks, springs and seeps, endangering some of the park’s most important and biodiverse wildlife habitat.
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As air pollution spikes in Europe’s cities prompt car-free days and talk of banning diesel cars, it’s easy to forget the other culprits behind the air quality crisis: diesel machines. Known in legislation by the innocuous term ‘non-road mobile machinery’, their air pollutant emission limits are now finally under revision.
The last directive dated back to 1997 and the new rules will set standards for decades to come. Air pollution is causing more than 450,000 premature deaths every year in Europe and a recent Eurobarometer survey confirmed that air pollution is now the biggest environmental concern of European citizens. Efficient regulation of emissions sources is therefore key to mitigating the exposure of citizens to air pollution.
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Microbeads, those tiny plastic beads included in personal care products for exfoliating power, have been popular for a number of years, with a growing number of companies sneaking them into toothpaste, body scrubs, soap and more. That’s despite evidence that they cause significant environmental problems, an issue that’s led a number of states to ban them or seriously consider such bans in order to protect the environment. But there’s more: There’s evidence that microbeads are also harmful for human health.
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About 34 million years ago, global temperatures took a dive, causing a sudden wave of extinctions among European mammals. In North America, however, life went on largely unscathed. A new study explains why: The rise of the Rocky Mountains had forced North American mammals to adapt to a colder, drier world.
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New research has found that the 6 gram brown thornbill mimics the hawk alarm calls of neighbouring species to scare a nest predator by convincing it that a much bigger and scarier predator - the brown goshawk - is on its way.
Currawongs, which raid the nests and hunt the chicks of thornbills, are also prey to goshawks. Although currawongs normally benefit from listening in on hawk alarm calls of other species, thornbills exploit this and turn it against them.
As well as issuing their own hawk alarm call, thornbills mimic those of the local species to create the impression of an impending hawk attack, which in turn distracts the pied currawong - a predator 40 times larger than the thornbill - providing thornbill nestlings with an opportunity to escape.
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A new study shows how huge influxes of fresh water into the North Atlantic Ocean from icebergs calving off North America during the last ice age had an unexpected effect – they increased the production of methane in the tropical wetlands. Usually increases in methane levels are linked to warming in the Northern Hemisphere, but scientists who are publishing their findings this week in the journal Science have identified rapid increases in methane during particularly cold intervals during the last ice age. These findings are important, researchers say, because they identify a critical piece of evidence for how the Earth responds to changes in climate.
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Researchers at the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL) have for the first time simulated the formation of structures called "plasmoids" during Coaxial Helicity Injection (CHI), a process that could simplify the design of fusion facilities known as tokamaks. The findings, reported in the journal Physical Review Letters, involve the formation of plasmoids in the hot, charged plasma gas that fuels fusion reactions. These round structures carry current that could eliminate the need for solenoids - large magnetic coils that wind down the center of today's tokamaks - to initiate the plasma and complete the magnetic field that confines the hot gas.
"Understanding this behavior will help us produce plasmas that undergo fusion reactions indefinitely," said Fatima Ebrahimi, a physicist at both Princeton University and PPPL, and the paper's lead author.
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Are males truly essential for reproduction? Female birds, reptiles and sharks living in captivity have sometimes surprised their keepers by giving birth even though, as far as anyone can remember, they have never been housed with a male. Scientists used DNA analysis to solve this mystery some time ago, showing that these offspring were produced by asexual reproduction, a process called parthenogenesis, or “virgin birth.” Although these events have captured tremendous public interest, it was unknown if this ever occurred in wild populations of these animals.
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