Science Links of the Week » Explorersweb

A passion for the natural world drives many of our adventures. And when we’re not actually outside, we love delving into the discoveries about the places where we live and travel. Here are some of the best natural history links we’ve found this week

Secret population of polar bears: Scientists have found a secret population of polar bears in Greenland. Nineteen subpopulations of polar bears exist across the Arctic, including one on the east coast of Greenland.

Now it turns out that there are two distinct groups in eastern Greenland, not one. The group in southeast Greenland never passes above 64˚N. And the bears in the northeast do not go further south than that line.

“We present the first evidence for a genetically distinct and functionally isolated group of polar bears in southeast Greenland, which meets [the] criteria for recognition as the world’s 20th polar bear researchers subpopulation,” the wrote in their new study.

They believe that this group has been there for 200 years. What makes it all the more baffling is they live in an environment considered near impossible for polar bears. For most of the year, there is no sea ice that far south. Instead, they live on the slopes around the fiords and hunt on glacial ice that calves in coastal inlets.

Seven new dwarf galaxies: Usually dwarf galaxies orbit evenly around the dominant galaxy. But seven newly found dwarf galaxies have clustered in one area, and astronomers don’t understand why.

M81, the large galaxy, lies 12 million light-years from Earth. Astronomer Eric Bell was observing it to look for surrounding dwarf galaxies. He found one definite dwarf galaxy and six possible ones, all positioned on the same side of M81. “That’s just bananas,” Bell said.

Cats recognize their friends’ names. Photo: Shutterstock

Smart cats

Cats know the names of their feline friends: Cats are able to decipher facial expressions and follow pointing cues. Two new experiments have shown that they can also match familiar cats’ (and humans’) names and faces. Researchers presented the cats with images of another familiar cat and uttered the familiar cat’s name. If the face and name did not match, the cats would pay attention to the monitor, expecting the face of the known cat to appear.

Cotton-candy pink salt flats: In Cabo Rojo National Wildlife Refuge, Puerto Rico you can find Las Salinas: cotton candy pink salt flats. Two shallow lagoons covering 505 hectares comprise the area.

Sometimes these lagoons are the normal crystalline white of any salt flat, but most of the time they are pink. The particular shade of pink depends on the algae, bacteria, salt, and water on that particular day. Dunaliella salina, the algae found in the lagoons, is rich in red and orange carotenoids. Similarly, the pigment in the bacteria is rhodopsin, which is also red. The fluctuations in algae and bacteria cause the changing color.

“We have rainy seasons, and when the salinity decreases, the Dunaliella survives and the ponds look brownish-red. During the dry season, it gets really salty. The Dunaliella dies and the…bacteria take over. Then it becomes pink,” says biologist Lilliam Casillas Martinez.

Drones that dangle a fishing line

Are drones the new way to fish? Giant trevally, one of Hawaii’s most prized game fish, are hard to find. They live in caves and on coral reefs. Now some fishermen have come up with a new way to locate the elusive fish — drones.

Fisherman Brandon Barques attaches a fishing line to his drone, then sends it out over the water. When he sees a cave on his video feed, he drops the line from the drone and waits. In 2017, he caught a 54kg giant trevally. Since then, drone fishing has become much more mainstream. You can buy drones that are built especially for fishing.

While some, like Barques, see this as a skill to master, others question whether it is fair. A drone can carry a line much further and take them into areas that were previously untouched. Many places are now starting to ban the practice until researchers can better assess the impacts.

Photo: Nasa’s Perseverance Mars Rover/@NASAPersevere

Space debris: On Monday, NASA’s Perseverance Rover sent back an unusual image. Between two rocks there is a shiny bit of material.

“My team has spotted something unexpected. It’s a piece of a thermal blanket that may have come from my descent stage, the rocket-powered jet pack that set me down…back in 2021,” commented the rover’s Twitter account.

The Outer Space Treaty from 1967 states that the contamination of pristine space environments must be avoided. Space scientist Andrew Coates has attempted to quell concerns. “Everything is sterilized before it goes to Mars,” he says. “And the space radiation helps during the nine-month trip to Mars, as does the harsh surface environment.”

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