Polar bear biopsies used to better understand Arctic pollutants

▲ Researchers collect fat tissue biopsies and blood samples from polar bears to study the impact of pollutants on their health. Photo: AFP

AFP

La Jornada Newspaper, Wednesday, May 21, 2025, p. 6

Norway. A Norwegian scientific expedition, which AFP was able to accompany, performed the first biopsies of fatty tissue from polar bears in Svalbard, in the Arctic, in April to assess the impact of pollutants on their health.

From a helicopter, veterinarian Rolf Arne Olden fires an anesthetic dart with an air rifle, paralyzing a bear that was running on the ice, frightened by the noise of the device.

The helicopter lands near the sleeping bear, scientists disembark, and proceed to extract thin strips of the animal's fatty tissue and take blood samples.

The idea is to reproduce as faithfully as possible how bears live in the wild, but in a laboratory , explains Laura Pirard, a Belgian toxicologist.

To do this, we take their tissue, cut it into very thin slices, and expose it to the same pressures they face, namely pollutants and stress hormones , adds Pirard, who developed the method.

Researchers keep the samples alive for several days on the expedition ship, subjecting them to contaminants and hormones.

They are then frozen for analysis in a laboratory once the team returns to land.

In addition to the veterinarian in charge of anesthetizing the bears, a pair of scientists work on the animals to perform biopsies, take blood samples, and fit them with electronic tracking collars.

Only polar bears can wear these collars, due to the shape of their necks.

The first health-tracking devices, small cylinders that record pulse and temperature, were fitted to five females last year.

This information, along with GPS data from the collars, gives scientists a picture of the bears' lifestyles and movements throughout the year.

The Norwegian Polar Institute has led the polar bear research program in Svalbard for 40 years.

This year, the team consisted of eight researchers: mission leader Jon Aars, his deputy, a space behavior expert, a veterinarian, and four toxicologists specializing in marine environments.

The eight traveled to the Arctic archipelago on a 100-meter research vessel, the icebreaker Kronprins Haakon.

We had a good season... We captured 53 bears, including 10 females with cubs or yearlings, and we placed 17 collars on them , Aars told AFP.

Land foods

Threatened by hunting until 1976, when a protection agreement came into force, polar bears are suffering the effects of global warming as sea ice, their natural habitat, melts rapidly.

The Arctic has been warming four times faster than the rest of the planet since 1979, according to a study published in the US journal Nature .

Svalbard polar bears now consume more land-based foods, rather than seals and the like. They still hunt seals, but they also eat reindeer, eggs, and even grass, although that doesn't provide them with energy , Aars says.

If they have very little sea ice, they must necessarily be on land , he adds, noting that they spend much more time on land than they did... 20 or 30 years ago .

However, the polar bear population in Svalbard has increased slightly over the past decade, he notes.

▲ A young howler monkey clinging to an adult male capuchin on Jicarón Island, Panama. AP Photo

Ap

La Jornada Newspaper, Wednesday, May 21, 2025, p. 6

Washington. A baby monkey clung to the back of an older male primate, its tiny fingers gripping the fur. But they're not related, and they're not even the same species.

Scientists found startling evidence of what they describe as monkey abductions while reviewing video footage from a small island in Panama. Capuchin monkeys were observed carrying at least 11 howler monkey offspring between 2022 and 2023.

"This was a very striking finding ," said Zoë Goldsborough, a behavioral ecologist at the Max Planck Institute for Animal Behavior in Germany. "We haven't seen anything like this in the animal kingdom ."

The monkeys' motivations are still under investigation. Capuchins are cat-sized monkeys found in South and Central America. They are long-lived, intelligent, and learn new behaviors from each other. A group of capuchins in Panama has even learned to use stone tools to crack open nuts and shellfish.

Goldsborough and other researchers from Max Planck and the Smithsonian Tropical Research Institute had set up more than 80 cameras to study capuchin tool use, but were surprised to see the first howler pups appear in early 2022.

The footage showed the capuchins walking and using their stone tools while carrying baby howlers on their backs. But the cameras didn't capture the abduction moments, which scientists said likely occurred in trees, where howlers spend most of their time.

Our view of this history is limited , said co-author Margaret Crofoot of Max Planck and the Smithsonian. The findings were published in the journal Current Biology .

In most or all cases, the howler monkey babies died, the researchers said. Infant howler monkeys would normally be carried by their mothers while they were still nursing. All of the infants in the video, ranging from a few weeks to a few months old, were too young to be weaned.

A hopeful part of me wants to believe that some escaped and returned to their mothers, but we don't know , Crofoot said.

Videos recorded some cases of young capuchin males still carrying howler monkey offspring that had died, likely from starvation. Many animals, from gorillas to orcas, have been observed carrying their own dead offspring, although scientists are unsure of the reasons.

Why did the capuchin males do this? There were no signs of deliberate aggression toward the young, and they were not eaten, which rules out predation.

We've spent hours racking our brains over why they would do this , Goldsborough said.

The first capuchin chick-snatcher may have had a confused caregiving motivation , or paternal instinct, because he displayed gentleness when interacting with the infants, she explained. Other males later copied his actions.

Researchers said they don't believe the capuchins have intentionally harmed the babies. So far, only one group of capuchins has been known to kidnap.