Science Links of the Week

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.

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

Scientists then released one female from a zoo in that area. After two months, the birds had paired. 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 again to bring it back. Today, they released eight captive Spix Macaws back into the forests of Brazil. They plan to release 12 more at the end of the year, and more in the future.

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

Beautiful, venomous, and destructive

The lionfish spreads to the Caribbean: Lionfish are known for both their beautiful patterns and their venom. Though the fish are not aggressive, their venom spines contain a neuromuscular toxin that 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 Sea. This is not a good thing. As an invasive species, they wreak havoc on reefs in the Atlantic. A single lionfish can reduce the number of juvenile fish in its feeding zone by 80 percent in just five weeks.

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

Fernanda the giant tortoise. Photo: Lucas Bustamante/PA

 

100 years later, a tortoise’s surprise appearance

Giant tortoise species thought to extinct found alive: For over a century, everyone thought that the Chelonoidis phantasticus species of giant tortoise was extinct. The last sighting of this fantastic creature was in 1906. Now researchers have found one on Fernandina Island in the western Galapagos.

Fernanda, as she has been named, first turned up in 2019. Since then, conservationists have wondered if she was, in fact, a member of this supposedly extinct species. Princeton researchers sequenced her genome and that of the male from 1906. They match. It means that Fernanda is different from the 13 other living tortoise species in the Galapagos.

Why do ocean predators dive so deep? Researchers tag large marine animals with tracking devices, sensors, and tiny cameras to capture life beneath the waves. Their monitoring turned up that nearly all large marine predators dove hundreds and thousands of metres down. But why?

The likely answer is food, but only one species — the northern elephant seal — has been seen doing this. Fish ecologist Simon Thorrold believes that they could also be diving to hide from other predators, for navigational reasons, or for the cooler temperatures of deep water.

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 down 11km, it is the deepest place in the ocean. Yang was looking for cosmic dust but he found something completely unexpected. Stuck to the magnetic needle probing the sediment was a tiny shelled organism.

The tiny creature was a single-celled creature called foraminifera, specifically Resigella bilocularis. There are many foraminifera on the seafloor, but these were different. They are magnetic.

Lots of animals use magnetic fields for navigation, and some can manufacture magnetite using the iron around them. But no one knows how or why foraminifera are magnetic. They are the first magnetic, single-celled organism found this deep. Researchers suspect R. bilocularis are making their own magnetite. The magnetite they produce is different from that in the surrounding sediment.

Rebecca McPhee is a freelance writer for ExplorersWeb.

Rebecca has been writing about open water sports, adventure travel, and marine science for three years. Prior to that, Rebecca worked as an Editorial Assistant at Taylor and Francis, and a Wildlife Officer for ORCA.

Based in the UK Rebecca is a science teacher and volunteers for a number of marine charities. She enjoys open water swimming, hiking, diving, and traveling.

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