A passion for the natural world drives many of our adventures. And when we’re not outdoors, we love to delve into the discoveries about the places we live and travel. Here are some of the best natural history links we found this week.
The spiders that choose death: For several spiders, sex is the beginning of the end. With orb-weaving spiders, widow spiders, and wolf spiders, the females eat the males alive after mating.
While most males try to escape, some male widow spiders start their own deaths. They turn back to the female’s mouth, almost forcing her to bite. Those who observed the bizarre ritual have noted that when males don’t flip back, the females didn’t try to eat them.
In terms of nutrition, the female spiders gain very little from eating the males. The average weight of the male spider is only two percent of the average female.
“She would do better with a fly … they [the males] force the females to kill them,” said biologist Lanka Sentenska. One theory for self-sacrifice is better reproductive opportunities. Studies have shown that males who were eaten transferred more sperm and were able to fertilize more eggs.
Three female bison released in Kent. Photo: Alexander Turner/The Guardian
Rewilding the UK
Wild bison return to the UK: On July 18, three wild bison stepped into the Kent countryside, in the south of England. They are the UK’s first wild bison in thousands of years.
The large animals have been released as “ecosystem engineers.” All three bison come from game reserves. The oldest female, the matriarch of the trio, is from the Scottish Highlands. To see also : India’s next big street food craze?. The two younger females are from Cork in Ireland. Ecologists hope the bison will help transform a dense pine forest into a natural forest.
One of their main food sources is bark, so their diet will kill some trees. Their large size will also open up trails through the forest and their love of dust baths will create more open space on the forest floor.
The changes they bring about should allow new wildlife to thrive. “We need to revolutionize the way we restore natural landscapes, relying less on human intervention and more on natural engineers such as bison, boars and beavers,” explains Evan Bowen-Jones of the Kent Wildlife Trust.
At the bottom of the Red Sea
Death Pools Under the Ocean: Deep-sea brines in the Red Sea are one of the most extreme environments on Earth. Read also : Embattled Spider Biologist Resigns From University Job.
There are only a few dozen of these hypersaline pools worldwide, and the majority are in the Red Sea. The anoxic pools are home to extremophiles. These are microbes that can endure such alien conditions and provide insight into how life began on Earth, or how life might survive on other planets.
The pools can also be deadly. “The brine is devoid of oxygen, any animal that wanders in it is immediately stunned or killed,” said marine geoscientist Sam Purkis.
A large number of fish, shrimp and eels live around the pools, possibly to clean up anything that falls victim to that environment.
Brine baths in the Red Sea. Photo: OceanX
India to reintroduce cheetahs
Cheetahs return to India: For the first time in 70 years, cheetahs will hunt across India’s grasslands. See the article : Secretary Blinken Meets with Indonesian Foreign Minister Marsudi – US State Department. Conservationists are releasing eight of the big cats into the Kuno-Palpur National Park in Madhya Pradesh, which has a suitable habitat.
India declared the cheetah extinct in 1952. The eight new cheetahs come from Namibia.
“The main goal of the cheetah reintroduction project is to establish a viable cheetah population in India that will allow the cheetah to fulfill its functional role as an apex predator,” the Indian Ministry of the Environment said.
Cheetahs from Namibia are released in India. Photo: Shutterstock
Mammalian ears hold the secret to warm-bloodedness: When did mammals and birds become warm-blooded and able to generate their own body heat? Researchers now think our ears may hold the secret.
Body temperature affects the shape of the inner ear. The semicircular canal system is a series of tubes that are filled with liquid. This helps with balance and movement. As the fluid heats up, it becomes more fluid, so the shape of the channels in warm-blooded animals must be different to do its job reliably.
“If you have to flee [from a predator] and your inner ear system doesn’t know where your head is, you’re going to die,” explains paleontologist Ricardo Araujo.
Researchers have studied the inner ears of a number of modern and fossilized species. They identified a shape that corresponds to warm-bloodedness in a 233-million-year-old fossil. This suggests that warm-blooded organisms existed before mammals roamed the Earth in the Late Triassic.
Are penguins in trouble?
Penguins may not be able to adapt to climate change: Penguins have evolved to survive in extreme environments. Yet 75% of penguin species are now extinct, so there’s a limit to how well they can adapt.
Researchers have found the genes that allow penguins to swim and survive in the cold. Some genes enabled shorter, denser flippers for diving, others led to the development of highly insulating white fat.
Despite their ability to cope with a difficult climate, they have the slowest known evolution among birds. “The slow evolution among penguins and the rate at which the Earth’s climate is currently changing does not bode well for penguins,” said seabird ecologist Barbara Wienecke.
