A passion for the natural world drives many of our adventures. And when we’re not 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.
Incredible journey of three African wild dogs: Three African wild dogs traveled more than 2,000km (1,300 miles) over nine months in search of a new home. This is double the previous record for the species.
African wild dogs are one of the most endangered mammals on Earth, so researches watched their journey with trepidation. “We’ve been watching with excitement, and nervousness, too. These dogs made history,” said carnivore expert Paola Bouley. At three years old they left their pack, something the dogs must do to have their own offspring and avoid inbreeding. Their birth pack resides in the Luangwa Valley in eastern Zambia.
After a month of movement, they entered foreign territory. The three sisters zigzagged across Zambia and Mozambique, skirted Zimbabwe, headed back into Zambia, and then settled in Zambezi National Park in Zimbabwe. Throughout the journey, they managed to avoid hunters and predators, dodged road traffic, and swam across flooded rivers teeming with crocodiles.
Pack animals by nature, they stuck together for the duration of the trip. One sister, known as EWD1355, took the lead. Researchers could follow the dogs as they had previously been tagged. “It’s miraculous they survived. There were so many human and ecological threats that could have ended this incredible journey,” the chief executive of the carnivore program Matther Becker explained.
World’s deepest shipwreck discovered: Explorers have discovered the deepest known shipwreck, the USS Samuel B Roberts. US explorer and entrepreneur Victor Vescovo found the sunken ship using his deep diving submersible, Limiting Factor. “Sammy B,” as the ship is known, lies at a depth of 6,895m. This is deeper than 98% of the world’s oceans.
The ship sank in 1944, during the Battle Off Samar in the Philippine Sea. When it sank, 89 men were killed. The 120 survivors were rescued after 50 hours clinging to life rafts.
Footage from the submersible shows the holes made by Japanese shells in the side of Sammy B. “We like to say that steel doesn’t lie and that the wrecks of these vessels are the last witnesses to the battles that they fought…those men, on both sides, were fighting to the death,” said Vescovo.
Photo: Shutterstock
Tiny pumpkin toadlets can’t land their jumps: Frogs normally land on their feet, but one species of toadlet is too small to do this. The pumpkin toadlet can jump, but instead of a graceful landing it will often belly flop onto its stomach or land on its back.
Researchers discovered that the toadlets’ inner ears cause these bumpy landings. Most animals have fluid inside their ears that flows over tiny hairs. In turn the movement of the hairs triggers electrical impulses in the nervous system to keep an animal balanced. The pumpkin toadlets are too small for this mechanism to work properly.
Pumpkin toadlets have the smallest semicircular ear canals of any known vertebrate. The fluid chamber does not send a strong enough signal, so instead of landing feet first they tumble to the ground. It seems they have traded the ability to land for their tiny size. “They’re not jumping around a lot and when they do, they’re probably not that worried about the landing because they’re doing it out of desperation. They get more benefits from being small than they lose from an inability to stick a landing,” explained Andre Confetti, co-author of the study.
Turtles have (almost) figured out how to stop ageing: A number of cold-blooded animals age so slowly it is as if they are not aging at all.
Turtles, crocodiles, and salamanders have such stunted aging that their lifespans are much greater than normal for their size. Scientists are investigating the mechanisms behind this in the hope that they can one day replicate the results in humans.
Some turtles have bodies that do not age, this means that their death is not related to age as it is in humans. “For the species we looked at, having protective adaptations, being larger, and taking longer to mature are all characteristics of species that age slower,” said ecologist David Miller.
Microplastics found in fresh Antarctic snow: For the first time, researchers have found microplastics in freshly fallen Antarctic snow. They have discovered the tiny pieces of plastic almost everywhere on Earth, including the tops of mountains and the deep sea. But until now, not in Antarctica.
A team of scientists collected snow samples from sites across Antarctica, including locations with almost no human activity. They were hopeful that the most remote locations would show no trace of plastic. Sadly, all samples contained plastic, with increasing amounts present the closer the sites were to research stations.
In total, scientists found 13 different types of plastic and an average of 29 particles of plastic per litre of melted snow. “Finding microplastics in fresh Antarctic snow highlights the extent of plastic pollution into even the most remote regions,” said Alex Aves, lead author of the study.
Photo: Shutterstock
Largest ever bacteria discovered: Bacteria are the oldest life forms on the planet. Now, microbiologists have discovered the largest known bacterium.
Thiomargarita magnifica is two centimetres long, a size that is unheard of in bacteria. “It is thousands of times larger than regular-sized bacteria. Discovering this bacterium is like encountering a human being as tall as Mount Everest,” said marine biologist Jean-Marie Volland.
Microbiologists first discovered the bacteria in 2009. Volland noticed white filaments attached to mangroves in Guadeloupe and took them back to the lab to investigate. He was shocked to find they were single-celled organisms. Researchers have now found thiomargarita magnifica in multiple locations around the French archipelago.
Researchers were also surprised to see the internal structure of the bacterium. Bacteria usually have free-floating DNA, it is one of their defining characteristics. This species has membrane bound DNA, one of only three species of bacteria known to display this.
