Chris Hadfield / CSA via Twitter

Canadian astronaut Chris Hadfield snapped this photo of Italy's Mount Etna from the International Space Station.

By Becky Oskin
Our Amazing Planet

Astronaut Chris Hadfield, the planet's most popular space shutterbug, snapped a spectacular photo of Italy's Mount Etna volcano streaming ash toward the sea early Thursday.

The volcano experienced the latest in a series of strong paroxysms, or short violent bursts, on Wednesday. For the first time, explosions and ash spewed into the air from Mount Etna's Voragine crater, while webcams trained on the fiery summit showed activity at Bocca Nuova crater as well.

Mount Etna's current eruption started with a stunning dawn lava fountain on Feb. 19, caught on video, followed in quick succession by three more paroxysms over the next two days. Then, on Feb. 23, lava fountains shot out from Bocca Nuova crater to a height of more than 2,600 feet (800 meters).

Ash cloaks the volcano's snow-covered slopes, but not enough to deter skiers. Small lava flows have also emerged from the most active craters. The volcano has four distinct craters at its summit: the two central craters, Bocca Nuova and Voragine; the northeast crater; and a new southeast crater.

Hadfield, an astronaut for the Canadian Space Agency, is aboard the International Space Station. He regularly posts amazing images of Earth on his Twitter feed.

Slideshow: Month in Space: February 2013

See more of astronaut Chris Hadfield's photos from the International Space Station, plus lots of other cosmic views, in the Month in Space Pictures slideshow for February.

Launch slideshow

Reach Becky Oskin at boskin@techmedianetwork.com. Follow her on Twitter @beckyoskin. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.

• Astronaut's Amazing Photos of Earth From Space
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Lovell et al., Current Biology

When it comes to camouflage, ground-nesting Japanese quail are experts. Mother quail know the patterning of their own eggs and choose laying spots to hide them best.

By Becky Oskin
Our Amazing Planet

Quail eggs are like fingerprints, a new study suggests.

The creamy blue-and-brown speckled eggs, splashed like a toddler's art project, vary among birds but are consistently patterned for individuals.

What's more, in a laboratory experiment, quail camouflaged their eggs according to their personal pattern, picking lighter sand for less-speckled eggs and darker sand for eggs with more brown splotches. What surprised researchers was the discovery that quail changed their approach to camouflage as their eggs got darker.

"It's as if they knew the characteristics of their own eggs and chose the best substrate with which to lay them," said George Lovell, lead study author and an expert on animal camouflage at Abertay University and the University of St. Andrews in Scotland.

Quail camouflage
Sitting at the bottom of the food chain, with a spot on just about every predator's dinner menu, quail and their eggs need good hiding places.

In the experiment, quail could lay clutches in sand with white, yellow, red or black hues. Researchers photographed each spot where the quail laid eggs and each location they ignored. The images revealed whether quail moms picked the sand color that offered the most camouflage. "They did really, really well," Lovell told OurAmazingPlanet.

Lovell et al., Current Biology

Japanese quail choose between two camouflage strategies to hide their eggs.

More than 50 percent of the time, quail chose the sand color offering the best or second-best protection for their own egg pattern, the study found.The findings appear Thursday in the journal Current Biology.

"The amazing thing is this change in strategy for the different eggs," Lovell said.

Quail with the creamiest egg colors picked white or yellow sand. This strategy, called background matching, aims to hide the eggs by blending into a similarly colored background.

Quail with darker, more splotchy eggs conceal their eggs not by matching a background color, but by trying to break up the egg's outline through its color pattern, an approach called disruptive coloration.

The same strategy the military uses in its camouflage patterning, the egg splotches disrupt its own outline with the colors and patterns on its shell, Lovell explained.

"What the spots seem to be doing it making a predator think an egg is different from an egg shape," he said.

Seeing splotches
The quail were raised in captivity at the University of Glasgow in Scotland, and had seen their eggs before the experiment started.

"It's possible that they learn the patterning through seeing eggs that they've laid," Lovell said. "In the wild, there is some evidence that birds are often less successful with their first clutch of eggs. It may be that at that point in time, they're not able to select the best place to lay their eggs."

Scientists think birds use patterning on eggs for camouflage, but the darker colors may also help strengthen weak spots or regulate temperature, Lovell said.

The shell color comes from two pigments : blue-green biliverdin and red-brown protoporphyrin, which are both breakdown products of hemoglobin (the oxygen-carrying protein found in the red blood cells of all vertebrates).

Reach Becky Oskin at boskin@techmedianetwork.com. Follow her on Twitter @beckyoskin. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.

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Taylor Edwards

This is a specimen of the new species, Morafka's Desert Tortoise (Gopherus morafkai), from Tiburon Island, Sonora, Mexico.

By Douglas Main
Our Amazing Planet

Desert tortoises, as their name suggests, don't encounter many large bodies of water.  But surprisingly, all turtles, even desert tortoises, can hear better underwater, recent research finds.

"If a desert tortoise decided to stick its head underwater, it could hear better," said Katie Willis, a University of Maryland doctoral student and co-author of a study published online this week in the journal PLoS ONE.

The findings shed light on the evolution of turtles, suggesting they all share an aquatic ancestor, the researchers said.

Willis and her co-authors took MRI and CT scans of the inner ears of many different species of turtles. They calculated that in every case these relatively large, air-filled sacks inside the skull resonated, or vibrated, more powerfully underwater, where sound waves travel more quickly than in air.

This process of hearing starts when sound waves vibrate the ear drum, which in turtles is flush with the outside of the head, Willis told OurAmazingPlanet. When the sound waves are at the right frequency, or pitch, they cause the inner ear to resonate and vibrate, aiding hearing, she said. This allows animals to better hear fainter sounds.

After taking measurements of the turtles' inner ears, the team found that all of them closely resembled those of aquatic turtles ; the ratio between the size of the skull and the size of the inner ear remained about the same, she said.

This observation, along with the team's resonance calculations, suggests that all turtles evolved from a common ancestor that lived in the water, she said.

"This strongly points to an aquatic origin for all turtles," Willis said. This has been a controversial topic, with some fossil evidence suggesting turtles have terrestrial origins.

She said the study should help better understand how hearing works in turtles and other animals, and where to place turtles in the evolutionary tree. It supports the hypothesis that turtles are more closely related to crocodiles and birds than to all other reptiles, contrary to previous theories.

Land turtles hear via sound vibrating their ear drums. Apparently it works well enough that evolution hasn't selected for a more specialized inner ear cavity, she said, a case of so-called neutral selection. Willis summed it up: "If it ain't broke, don’t fix it."

Reach Douglas Main at dmain@techmedianetwork.com. Follow him on Twitter @Douglas_Main. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.

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Mark Plotkin of the Amazon Conservation Team

Waterfalls in Colombia's Chiribiquete National Park.

By Douglas Main
Our Amazing Planet

The Colombian government may double the size of an enormous, diverse reserve, according to news reports. The new park would incorporate the lands of two tribes that have little or no contact with the outside world.

The Chiribiquete National Park is home to a dazzling array of plant and animal life, including 300 bird species, seven monkey species and 300 butterfly species, according to mongabay.com, an environmental news website.

The plan, formulated last year by the government, would more than double the park's area, to a total of 11,580 square miles (30,000 square kilometers) of pristine rain forest, an area larger than the state of Massachusetts.

"The plan to expand Chiribiquete is great for Colombia," said Liliana Madrigal of the Amazon Conservation Team, a nonprofit group that partners with indigenous groups in Colombia to preserve rain forests. "Chiribiquete already protects an enormous wealth of flora and fauna, but its enlargement now also will facilitate the protection of voluntarily isolated indigenous peoples that are believed to inhabit the park and help ensure their right to remain uncontacted," Madrigal said.

The park is known for its unusual rock formations and stunning waterfalls. The new park would include at least 32 cave painting sites with about 250,000 drawings, according to the website.

The expansion announcement comes a year after passage of a decree that requires the government to set aside land for voluntarily isolated indigenous groups, and the plan has been approved by seven tribal communities that live near Chiribiquete, mongabay reported. The Colombian Ministry of Environment is now negotiating with the Ministry of Mines to figure out what to do with land scheduled for oil exploration; a final decision is expected by March, according to the website.

Reach Douglas Main at dmain@techmedianetwork.com. Follow him on Twitter @Douglas_Main. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.

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NSIDC

Pine Island Glacier (right) and Thwaites Glacier (middle) in December 2012, as seen by the MODIS instrument on NASA's Terra satellite.

By Becky Oskin
Our Amazing Planet

Like a plug in a leaky dam, little Pine Island Glacier holds back part of the massive West Antarctic Ice Sheet, whose thinning ice is contributing to sea level rise.

In recent decades, Pine Island Glacier's rapid retreat raised fears that the glacier could "collapse," freeing the ice sheet it buffers to flow even more rapidly into the southern seas. The West Antarctic Ice contributes 0.15 to 0.30 millimeters per year to sea level rise.

The big question is whether the hasty retreat is a recent change, caused by climate change, or a more long-term phenomenon.

"We need to know if what we observe today is something that started perhaps at the end of the last Ice Age or something that started in more recent times," said Claus-Dieter Hillenbrand, a marine geologist with the British Antarctic Survey.

Pine Island Glacier's small ice shelf, a platform of ice floating on the ocean's surface, acts as a plug, holding the rest of the ice stream in place on land. As warm ocean currents melt the ice shelf from below, inland glaciers flow down to the coast and feed the thinning ice shelf. Changes to Antarctic wind currents, driven by global warming, have pushed relatively warmer ocean waters beneath the ice shelves.

In the past 20 years, Pine Island Glacier's grounding line, the location where the glacier leaves bedrock and meets the ocean, has retreated at a rate of more than 1 kilometer a year. The glacier itself has thinned at a rate of 5 feet (1.5 meters) a year since the 1990s, and its flow rate has accelerated by 30 percent in the past 10 years.

NASA Earth Observatory

A massive crack in Pine Island Glacier is steadily growing, as seen in a Sept. 14, 2012, satellite image.

Pine Island Glacier stretches only 45 miles (40 km) across where it meets the ocean, but it drains an area of 62,665 square miles (162,300 square km).

To determine why Pine Island Glacier and its nearby cousin, Thwaites Glacier, are changing so rapidly, the British Antarctic Survey looked to the past. They studied sediments from Pine Island Bay, where the ice shelves stick tongues into the ocean.

Microfossils in mud retrieved by ocean drilling aboard a research ship pinpoint when and were ice covered the bay. This is because the microscopic marine life is only present if the ice shelf is absent. Radiocarbon dating of the fossils gave researchers a 10,000-year history of the past location of the ice.

"For the first time, we can put these modern observations of fast grounding-line retreat in a long-term context," Hillenbrand told OurAmazingPlanet.

"We can show that the present grounding-line retreat is really exceptional over a longer time scale, over the last 10,000 years," he said. "In the previous 10,000 years, the grounding line retreated by just about 90 kilometers (56 miles), but in the last 20 years, it retreated by 25 kilometers (15 miles)."

The results appear in the January 2013 issue of the journal Geology.

Hillenbrand and his colleagues also discovered there could have been three or four episodes of rapid retreat in the past 10,000 years, but these were short-lived, lasting just 25 to 30 years. Researchers found no evidence the glaciers had advanced in the past 10,000 years.

"Some say the fast grounding-line retreat will stop in a few years, others in a few decades. Others say that this retreat will actually continue and may lead to the complete collapse of the Pine Island Glacier drainage system," Hillenbrand said. "What we know is that, on the basis of this data, the current retreat is unprecedented."

As Pine Island Glacier retreats, it drops huge icebergs. In 2011, NASA's Operation IceBridge discovered a giant crack crossing the ice shelf. (The IceBridge expedition tracks yearly changes in the Antarctic ice.) The fissure, about 20 to 25 km inland from the edge of the ice shelf, could birth an iceberg the size of New York City.

IceBridge scientists say the calving is part of the natural process by which glaciers flow to the sea. The last calving event (the sudden release of ice) let loose in an iceberg that measured 26 by 11 miles (42 km by 17 km) in 2001. The Pine Island Glacier seems to generate big bergs on a decade-long cycle, scientist say. [ Photo Album: Antarctica, Iceberg Maker ]

The British team now plans to investigate what's driving the thinning of the glaciers in Pine Island Bay. "We're pretty sure the most important driver is warm ocean water, but this is still an open question," Hillenbrand said.

"Now that we have this retreat history, we can study the past dynamic behavior of these glaciers, so we can predict better the future behavior of these ice streams and their contribution to future sea level rise."

Reach Becky Oskin at boskin@techmedianetwork.com. Follow her on Twitter @beckyoskin. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.

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Nadine Lysiak, Woods Hole Oceanographic Institution

Woods Hole Oceanographic Institution scientist Mark Baumgartner secures a glider (with its wings removed) after it was recovered Dec. 4 from its three-week mission to record and transmit whale songs.

By Douglas Main
Our Amazing Planet

Two underwater robots outfitted with equipment to detect whale songs heard the calls of nine critically endangered North Atlantic right whales in the Gulf of Maine last month, just east of New England.

The whales are thought to use the area to mate between November and January, according to a release from the Woods Hole Oceanographic Institution (WHOI) in Massachusetts, whose researchers led the project.

The finding was reported to the National Oceanographic and Atmospheric Administration's Fisheries Services, which is charged with protecting these animals under the Marine Mammal Protection Act. The agency put in place a "dynamic management area," meaning mariners in the area were asked to slow their vessels to avoid striking the animals.

The robots also detected fin, sei and humpback whales in the area, the first time autonomous vehicles have recorded songs of multiple whale species. The animals were recorded about 60 miles (97 kilometers) south of Bar Harbor, Maine, according to the release. Besides listening for whale songs, the robots also tested a number of variables to see why the area might be an appealing breeding ground, measuring water temperature and salinity, as well as samples of water to look for tiny animals called zookplankton upon which the whales feed.

Detecting whale songs
The 6-foot-long (1.8 meters) underwater robots look like yellow torpedoes, and use a quiet motor to submerge themselves before surfacing every few hours to transmit data back to computers and researchers on land.

The information the robots provide is essential for understanding the whale's behavior in this area, which is little studied since the animals usually pass through in the late fall and winter when temperatures are freezing and weather is unforgiving, the release noted.

Detection of the whale songs allowed researchers aboard the research vessel, Endeavor, to locate the whales and take photographs of them. This allowed scientists to identify four previously known right whales. The robots represent a large improvement of the previous methods used to find whales: the human eye.

"We've been doing visual based surveys for a long time — either from a plane or a boat," said Sofie Van Parijs, a collaborating researcher, in the statement. "They have a lot of value, but they are limited, especially at certain times of the year. These gliders provide a great complement to this system. Knowing where right whales are helps you manage interactions between an endangered species and the human activities that impact those species."

North Atlantic right whales can weigh 140,000 pounds (63,500 kilograms) and grow up to 55 feet (16.7 m), according to NOAA. They are critically endangered, and only 300 to 400 of the animals remain, NOAA reports.

Reach Douglas Main at dmain@techmedianetwork.com. Follow him on Twitter @Douglas_Main. Follow OurAmazingPlanet on Twitter @OAPlanet. We're also on Facebook and Google+.

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