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article image Polar bears forced to forage eggs as warming shrinks hunting grounds – Digital Journal

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Hungry polar bears are increasingly foraging on seabird eggs as climate change shrinks their Arctic hunting grounds, but research published Wednesday on the phenomenon highlights the struggle these apex predators have to adapt to their rapidly changing environment.

The climate change threat to polar bears is well known, driven by the extraordinary pace of change in the Arctic, which is warming twice as fast as the planet as a whole.

This is already leading to dwindling sea ice, cutting short the time they have to hunt seals, their preferred prey.

With a growing imperative to find alternative sustenance, polar bears have been pushed further afield in search of food, including scavenging in areas populated by humans.

The polar bear

Jonathan WALTER, AFP

Some bears are also coming ashore at the same time seabirds are nesting and are snacking on their eggs.

To measure how efficient these top-of-the-food-chain predators were at this foraging — and therefore how useful the eggs are to provide energy in their diets — researchers in Canada used drones to monitor them feeding from common eider duck nests on Mitivik Island, in Nunavut.

– Inefficient hunting –

The study, published in the journal Royal Society Open Science, tracked how the bears approached the nesting site over a period of 11 days, as the number of eggs were depleted.

“We found that later-arriving bears increasingly visited more empty nests and did not travel in an energy-minimizing way, but became less picky in the clutches they consumed,” said lead author Patrick Jagielski, of the Great Lakes Institute for Environmental Research at the University of Windsor.

The climate change threat to polar bears is well known  driven by the extraordinary pace of change i...

The climate change threat to polar bears is well known, driven by the extraordinary pace of change in the Arctic, which is warming twice as fast as the planet as a whole

Steven C. AMSTRUP, POLAR BEARS INTERNATIONAL/AFP/File

Bears also did not consistently realise that the sudden appearance of a fleeing eider hen meant eggs were nearby.

“This study demonstrates that, while species are able to incorporate ‘less preferred’ resources into their diet when their primary prey becomes more difficult to obtain, they may not be able to do so efficiently,” the authors said.

Jagielski told AFP that the research could not speak more broadly to polar bears’ ability to cope with climate change, but did raise questions about the energy value of eggs as an alternative food source.

– ‘Extinction event’ –

There are approximately 25,000 Ursus maritimus left in the wild today in 19 population subgroups distributed across the Arctic in Alaska, Canada, Greenland, Norway, and Russia.

In July, a study published in Nature Climate Change estimated the species would be starved to extinction by 2100.

Researchers looked both at predictions for climate heating and data on the increasing portion of the year that the bears’ must survive on their fat reserves.

Earlier this month, a paper published in the journal Global Change Biology found that polar bears maintained highly specialized diets of soft blubber and flesh for hundreds of years — even during previous periods of Arctic warming.

Researchers at Vanderbilt University, who examined dental wear in skulls held in museums, said polar bears are so specialised in their diets that they may struggle to adapt to the warming Arctic.

But they said an increase in encounters with grizzly bears could provide one evolutionary option, noting incidents where the two species have produced offspring.

Jack Tseng of University of California, Berkeley said in a related commentary that the fate of the polar bear was ultimately “inextricably tied” to how the momentum towards a “tipping point” for Earth’s flora and fauna is managed.

“Will polar bear populations have to rely on hybridization with grizzly bears as a means of adaptation to a changing environment,” said Tseng, who was not involved in the study.

“Will they successfully shift their hunting strategy to reduce competition with their sister species or will they become one more casualty in the ongoing extinction event that is accelerating in this century?”

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2.8-pound meteorite from space crashes roof of Canadian woman’s home, falls on bed – The Tribune India

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Tribune Web Desk

Chandigarh, October 16

Ruth Hamilton (66) had a disturbed awakening on October 3 when a large meteorite plunged from space, through her roof and landed in her bed.

Ruth, resident of Golden, British Columbia, woke up to the sound of a crash and her dog barking on October 3 around 11.35 pm.

Speaking with Canadian Press, she said: “I’ve never been so scared in my life, adding that, “I wasn’t sure what to do so I called 911 and, when I was speaking with the operator, I flipped over my pillow and saw that a rock had slipped between two pillows.”

She told CTV News: “I didn’t feel it.”

“It never touched me. I had debris on my face from the drywall, but not a single scratch.”

A police officer arrived on the scene, but suspected the object that landed in Hamilton’s bed was from a nearby construction site.

“He called the [construction site] and they said they hadn’t done a blast but that they had seen an explosion in the sky and, right then and there, we realised it was a meteorite,” she told the Canadian Press.

It turns out that the 2.8-pound space rock, about the size of a small cabbage, was part of a meteor shower identified by Alan Hildebrand, a planetary scientist in the Department of Geoscience at the University of Calgary, and his colleagues.

The group said the trajectory of the meteorite that hit Hamilton’s house would have made it visible throughout southeastern British Columbia and central and southern Alberta.

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NASA to launch first space probe to study Jupiter’s Trojan asteroids

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NASA is set on Saturday to launch a first-of-its kind mission, dubbed Lucy, to study Jupiter’s Trojan asteroids, two large clusters of space rocks that scientists believe are remnants of primordial material that formed the solar system’s outer planets.

The space probe, packed inside a special cargo capsule, is due for liftoff from Cape Canaveral Air Force Station in Florida at 5:34 a.m. EDT (0934 GMT), carried aloft by an Atlas V rocket from  United Launch Alliance (UAL), a joint venture of Boeing Co and Lockheed Martin Corp.

If all goes according to plan, Lucy will be hurled into space on a 12-year expedition to study a record number of asteroids. It will be the first to explore the Trojans, thousands of rocky objects orbiting the sun in two swarms – one ahead of the path of giant gas planet Jupiter and one behind it.

The largest known Trojan asteroids, named for the warriors of Greek mythology, are believed to measure as much as 225 kilometers (140 miles) in diameter.

Scientists hope Lucy’s close-up fly-by of seven Trojans will yield new clues to how the solar system’s planets came to be formed some 4.5 billion years ago and what shaped their present configuration.

Believed to be rich in carbon compounds, the asteroids may even provide new insights into the origin of organic materials and life on Earth, NASA said.

“The Trojan asteroids are leftovers from the early days of our solar system, effectively the fossils of planet formation,” principal mission investigator Harold Levison of the Southwest Research Institute in Boulder, Colorado, was quoted by NASA as saying.

No other single science mission has been designed to visit as many different objects independently orbiting the sun in the history of space exploration, NASA said.

As well as the Trojans, Lucy will do a fly-by of an asteroid in the solar system’s main asteroid belt, called DonaldJohanson in honor of the lead discoverer of the fossilized human ancestor known as Lucy, from which the NASA mission takes its name. The Lucy fossil, unearthed in Ethiopia in 1974, was in turn named for the Beatles hit “Lucy in the Sky with Diamonds.”

Lucy the asteroid probe will make spaceflight history in another way. Following a route that circles back to Earth three times for gravitational assists, it will be the first spacecraft ever to return to Earth’s vicinity from the outer solar system, according to NASA.

The probe will use rocket thrusters to maneuver in space and two rounded solar arrays, each the width of a school bus, to recharge batteries that will power the instruments contained in the much smaller central body of the spacecraft.

 

(Reporting by Steve Gorman in Los Angeles, Editing by Rosalba O’Brien)

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Darwin family microscope to be sold at auction

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A microscope Charles Darwin gave his son Leonard and which has remained in the family for nearly 200 years is headed for auction in December, and is expected to fetch up to $480,000.

The instrument was designed by Charles Gould for the firm Cary around 1825 and is one of six surviving microscopes associated with the British naturalist, according to auction house Christie’s.

The date of its manufacture coincides with the time when Darwin was studying zoophytes, organisms such as coral and sea anemone.

“It is just incredibly spine tingling to look through this and see the microscopic world that Darwin would have seen in the 1820s and 30s,” James Hyslop, Head of Department, Scientific Instruments, Globes & Natural History, at Christie’s, told Reuters.

“Later in his life in 1858, there’s a wonderful letter that he writes to his eldest son saying young Lenny was dissecting at his microscope and he said ‘Oh Papa, I should be so glad of this for my whole life’. It’s wonderful to have that family connexion of Charles Darwin just before he becomes internationally famous.”

Darwin published his groundbreaking work “On the Origin of Species” in 1859.

The microscope will be offered at Christie’s Valuable Books & Manuscripts auction on Dec. 15, and has a price estimate of 250,000 – 350,000 pounds ($343,050 – $480,270).

“Charles Darwin is one of the biggest names in the Science, and collectors for Darwiniana (relating to Darwin) are truly international in breadth,” Hyslop said.

($1 = 0.7288 pounds)

 

(Reporting by Marissa Davison; Writing by Marie-Louise Gumuchian; Editing by Mike Collett-White)

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