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.
Lizards twist to shed their tails
How do lizards keep their detachable tail attached?: Lizards use self-amputation as a defense mechanism. The detached tail is a decoy that helps them escape from predators. Curious scientists wanted to know how they can let go of their tails when needed but keep it attached the rest of the time.
The breakpoint of the tail contains mushroom-shaped micropillars that act like plugs and sockets. The structure allows adhesion under tension but will also fracture when twisted, allowing the tail to separate as the lizard twists its body.
Ghost shark hatchling.
Two ghosts
Baby ghost shark found by scientists: Scientists in New Zealand have found a newly hatched ghost shark. Ghost sharks are deep-water sharks that live at a depth of 1,200m, off the east coast of the country’s South Island.
“We don’t know a lot about ghost sharks,” said fisheries scientist Brit Finucci. “What we do know mostly comes from adult specimens. So it’s very rare to find a juvenile…that’s why I got quite excited.”
Scientists were able to identify the ghost shark because its belly was still full of egg yolk, but they are still unsure of the exact species. Ghost sharks are the most ancient lineage of cartilaginous fish, and researchers are still discovering new species. In time, genetic samples will further identify the rare find.
Aceredo. Photo: Miguel Vidal/Reuters
Ghost village emerges from the deep: Droughts in Spain have uncovered a ghost village. In 1992, the Spanish government flooded the Aceredo village in the northwestern Galicia region to create the Alto Lindoso reservoir.
The water level has now dropped to 15% of the dam’s capacity, and the village has remerged. The site intrigues locals and tourists. Buildings are still intact, and water a drinking fountain still pours from a rusty pipe. The mayor of the local council blamed the lack of rain over recent months for the low water levels. She also noted there has been “quite aggressive exploitation” of reservoirs by Portugal’s power utility.
Sun breaks down spilled oil
Sunlight helps clean up oil spills: Sunlight plays a much larger role in cleaning up oil spills than we first thought. It has removed up to 17% of the surface oil from the 2010 Deepwater Horizon oil spill in the Gulf of Mexico. The sunlight starts oxygenation reactions that can transform insoluble crude oil into water-soluble products. This process is called photo-dissolution.
They found that shorter wavelengths of light dissolved more oil. Latitude and oil slick thickness also affect the rate of photo-dissolution. Scientists are not sure what impact the new water-soluble compounds have on marine ecosystems. At the moment, oil spill models do not include photo-dissolution. However, this discovery may improve future oil spill models.
An Ice Age bounty
Dozens of Ice Age animal remains found in England: Archaeologists have uncovered the remains of many ancient animals in Devon, England. Builders found the remains during the construction of a new town.
The team found a woolly mammoth tusk, molar tooth, and bones; a woolly rhinoceros skull; an almost complete wolf skeleton; and partial remains of hyena, horse, reindeer, mountain hare, and red fox. “To find such an array of artifacts untouched for so long is a rare and special occurrence,” says archaeologist Rob Bourn.
These creatures lived during the last Ice Age, from 30,000 to 60,000 years ago. It is still unclear whether all the specimens found came from the same or different time periods. There are two theories. First, some animals may have fallen into a pit and died, and the scavengers that followed them in could not escape either. Second, some of the animals may have died elsewhere. Over time, water washed the bodies into the site.
Bald Eagle. Photo: Shutterstock
Lead poisoning in bald and golden eagles: Nearly half of all bald and golden eagles in the U.S. have lead poisoning. Researchers studied eagles in 38 states. Chronic lead poisoning appeared in 46% of bald eagles and 47% of golden eagles. These levels of poisoning will stunt the annual population growth of both species.
Though the population loss will be smaller for golden eagles, the stunted population growth has conservationists worried. While bald eagle populations have grown to over 300,000 in the U.S., only 40,000 golden eagles remain.
Lead poisoning occurs when the birds ingest the metal, and most of the lead comes from ammunition. Eagles often feast on carcasses. Ammunition in those carcasses gets into the eagle’s bloodstream and builds up in their bones.
