Scientific Links of the Week »Explorersweb

The passion for the world of nature drives many of our adventures. And when we’re not actually out, we like to delve into the discoveries of where we live and travel. Here are some of the best natural history links we found this week.

Spix Ara, reintroduced into Brazilian forests: Since 1995, conservationists have been trying to save Spix Ara. This blue-gray parrot is one of the rarest birds in the world. Throughout the 19th century, they were hunted for their beautiful plumage. Until the 1990s, only one known bird remained in the wild, a male.

Scientists then released a female from a zoo in the area. Two months later, the birds mated. Two weeks later the female disappeared, and a few years later the male died. Many believed that this was the end of the species.

Now conservationists are trying to bring it back. Today, they released eight captured Spix Ara back into the forests of Brazil. They plan to release another 12 at the end of the year and in the future.

“There are very few reintroduction programs around the world that have done something like this, and none with parrots or macaws,” said wildlife biologist Thomas White.

Beautiful, poisonous and destructive

Lionfish are distributed in the Caribbean: Lionfish are known for both their beautiful patterns and their venom. Although fish are not aggressive, their venomous spines contain neuromuscular toxins, which they use to protect themselves.

Lionfish are native to the Pacific and Indian Oceans, but have spread to the Gulf of Mexico and the Caribbean. This is not a good thing. As an invasive species, they wreak havoc on reefs in the Atlantic Ocean. A lionfish can reduce the number of young fish in its feeding area by 80 percent in just five weeks.

At the same time, they multiply very quickly. Females can produce 25,000 eggs every few days. Communities around the Caribbean are trying to save their reefs by controlling lion populations.

Fernanda the giant tortoise. Photo: Lucas Bustamante / PA

100 years later a surprising appearance of a turtle

Living species of giant tortoises believed to be extinct found: For more than a century, everyone thought so Chelonoidis phantasticus a species of giant tortoise is extinct. The last sighting of this fantastic creature was in 1906. Now researchers have found one on the island of Fernandina in the western Galapagos.

Fernanda, as she was named, first appeared in 2019. Since then, conservationists have wondered if she is not actually a member of this supposedly extinct species. Researchers at Princeton have sequenced her genome and that of the man since 1906. They match. This means that Fernanda is different from the 13 other living turtle species in the Galapagos.

Why do ocean predators dive so deep? Researchers are marking large marine animals with tracking devices, sensors and small cameras to capture life under the waves. Their monitoring showed that almost all large marine predators dive hundreds and thousands of meters down. But why?

The probable answer is food, but only one species – the northern elephant seal – has been observed to do so. Fish ecologist Simon Thorold believes that they can also dive to hide from other predators, for navigation reasons or due to lower deep water temperatures.

Why do whale sharks and other marine predators dive so deep? Photo: Shutterstock

Magnetic microbes

Strange creatures in the Mariana Trench: In 2018, graduate student Yang Hao collected sediment from the Mariana Trench. Reaching 11 km down, this is the deepest place in the ocean. Young searched for cosmic dust, but found something completely unexpected. Glued to the magnetic needle probing the sludge was a small organism with shells.

The little creature was a single-celled creature called foraminifera in particular Resigella bilocularis. There are many foraminifera on the seabed, but they were different. They are magnetic.

Many animals use magnetic fields for navigation, and some can produce magnetite using the iron around them. But no one knows how and why foraminifera are magnetic. They were the first single-celled magnetic organism discovered so deeply. Researchers suspect R. bilocularis make their own magnetite. The magnetite they produce is different from that in the surrounding sediment.

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