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.

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.

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.

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.

Northeastern University researchers have found that the bacterium that causes Lyme disease forms dormant persister cells, which are known to evade antibiotics. This significant finding, they said, could help explain why it’s so difficult to treat the infection in some patients.

The population of the Amur tiger in Russia has increased to as many as 540 individuals over the last ten years, according to figures released by the Russian government.
 
“I am pleased to see that the number of Amur tigers in Russia has increased in all the key areas where WWF has been working for many years,” said Igor Chestin, Head of WWF-Russia. “This success is due to the commitment of Russia’s political leadership and the tireless dedication of rangers and conservationists in very difficult conditions.”

A glass of seawater is teeming with life, and recent research reveals more about what ocean water contains. Microscopic creatures in the world's oceans weigh more than all of the fish in the sea and produce about half of Earth's oxygen.

Yet the ecology of marine microbes, which are crucial for everything from absorbing carbon dioxide from the air to regulating the productivity of major fisheries, are only beginning to be understood.

No one knows what's killing them, but scientists estimate that almost half of the world's saiga (Saiga tatarica) have perished since May 10th. To date, researchers on-the-ground unofficially estimate that 120,000 saiga have died in Kazakhstan from what appears to be a wildly virulent disease, although no cause has been ruled out. Saiga are bizarre-looking, Ice Age antelopes that once roamed Central Asia in the millions, but are now listed as Critically Endangered. 

Biologists at UC San Diego have discovered that a tiny single-celled parasite may have a greater-than expected impact on honey bee colonies, which have been undergoing mysterious declines worldwide for the past decade. In this week’s issue of the journal PLOS ONE, the scientists report that a microsporidian called Nosema ceranae, which has been known to infect adult Asiatic and European honey bees, can also infect honeybee larvae.

As snowpack levels decline with the warming climate, many streams will experience less water flow, especially during summer months, potentially exposing more fish to predation by birds and other animals. A new study has found that providing adequate shade and cover in small streams may reduce predation on trout by as much as 12 percent, from just one species of bird – the kingfisher.