Polar bears are increasingly foraging on seabird eggs as climate change shrinks their arctic hunting grounds, but research published yesterday on the phenomenon highlights the struggle the predators have to adapt to their rapidly changing environment.
Dwindling sea ice is 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.
Some are also coming ashore at the same time as seabirds are nesting to snack on their eggs.
To measure how efficient the bears 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.
The study, published in the journal Royal Society Open Science, tracked how the bears approached the nesting site over 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.
Bears also did not consistently realize that the sudden appearance of a fleeing eider hen meant that 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 wrote.
Jagielski said 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.
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 last year, a study published in Nature Climate Change estimated that the species would be starved to extinction by 2100.
Researchers looked 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 that polar bears are so specialized in their diets that they might struggle to adapt in a warming arctic.
However, an increase in encounters with grizzly bears could provide one option, as the two species have produced offspring, they said.
BEIJING BAILOUT: Pyongyang’s economic woes would not lead to famine because China will not let that happen due to its fear of a pro-US unified Korea, experts say North Korean leader Kim Jong-un has called for another “arduous march” to fight severe economic difficulties, for the first time comparing them to a 1990s famine that killed hundreds of thousands. Kim had previously said his nation faces its “worst-ever” situation due to several factors — including the COVID-19 pandemic, US-led sanctions and natural disasters in the summer last year — but it is the first time he has publicly drawn a parallel with the deadly famine. North Korea monitoring groups have not detected any signs of mass starvation or a humanitarian disaster, but Kim’s comments still suggest how seriously he views
‘VOSTOK 1’: The first flight attempt is planned to coincide with the 60th anniversary of the first space flight by Soviet cosmonaut Yuri Gagarin NASA’s Ingenuity mini-helicopter has survived its first night alone on the frigid surface of Mars, the US space agency said, hailing it as “a major milestone” for the tiny craft as it prepares for its first flight. The ultra-light aircraft was dropped on the surface on Saturday after detaching from the belly of the Perseverance rover, which touched down on Feb. 18. Detached from the Perseverance, Ingenuity had to rely on its own solar-powered battery to run a vital heater to protect its unshielded electrical components from freezing and cracking during the bitter Martian night, where temperatures can plunge as low as
LOSING CONTROL? Fitch Solutions said that a revolution pitting the military against the anti-coup movement and ethnic militias was likely due to the rising violence Burmese security forces yesterday arrested Paing Takhon, a model and actor who had spoken out against a military coup, his sister told reporters, as people placed shoes filled with flowers in parts of Yangon to commemorate dead protesters. Troops on Wednesday opened fire on protesters, killing at least 15 people and wounding dozens, protesters and media said. Nearly 600 civilians have been killed by security forces since the junta in February seized power from the elected government of Aung San Su Kyi, the Assistance Association for Political Prisoners said on Wednesday. The advocacy group said that 2,847 were being held in detention. A spokesman
A years-long David and Goliath fight which has seen two Australian surfers take on a Chinese-linked company over alleged damage of an idyllic Fijian island has come to its conclusion after a court handed down a guilty verdict against the developers yesterday. The case has been described by Pacific legal experts as a “watershed” moment that tested Fijian environmental laws, as well as the willingness of the nation — which presents itself as a global climate leader — to “walk the walk” on environmental issues. Freesoul, a Chinese-linked company, in 2018 began work on Malolo Island, with plans to build Fiji’s largest