A passion for the natural world drives many of our adventures. And when we’re not outside, we love delving into discoveries about the places we live and travel. Here are some of the best natural history links we’ve found this week.
Networking dolphins: Bottlenose dolphins form large multi-level alliance networks. Humans are the only animals that form larger groups.
The male dolphins in Shark Bay, Australia, formed two or three primary bonds and up to 14 secondary alliances. Dolphins in a primary alliance cooperatively pursue an individual female. Those in the secondary group compete with other alliances over female dolphins.
“The cooperative relationships between groups, rather than simply alliance size, allows males to spend more time with females, thereby increasing their reproductive success,” said biologist Simon Allen.
A 31,000-year-old amputation
The earliest known amputation: Archaeologists in Borneo think that they have discovered the earliest successful amputation. A 31,000-year-old skeleton shows that the lower left leg had been removed and that the young person survived.
The discovery suggests that foragers in South East Asia had significant medical knowledge. The amputation predates the next earliest known surgery by 24,000 years. Scientists initially thought that the lower leg had broken away from the skeleton. But closer inspection showed there was a clean cut with overgrowths on the tibia and fibula where the rest of the leg should be. The overgrowths resemble those seen in modern-day amputations.
“It’s a remarkable find, and I do think it’s consistent with an amputation that’s been done surgically,” said bio-archaeologist Charlotte Roberts.
Drumming primates
Primates show off their signature drum beats: Primates in Borneo drum messages to each other on tree roots.
Different individuals have different signature sounds. This means that they can send signals over long distances and reveal who they are.
“It surprised me that I was able to recognize who was drumming after just a few weeks in the forest. But their drumming rhythms are so distinctive that it’s easy to pick up on them,” researcher Vesta Eleturi said.
The Sitka spruce on Campbell Island is the world’s most remote tree. Photo: Jocelyn Turnbull/GNZ Science
The world’s loneliest tree: A Sitka spruce on Campbell Island in New Zealand might be the loneliest tree in the world. The nine-metre spruce is the only tree on this remote island in the Southern Ocean.
Researchers plan to use the tree, which was planted in the early 1900s, to gain an insight into the carbon sink capacity of the Southern Ocean.
The Southern Ocean takes up 10% of our carbon emissions but has proven difficult to study. The normal method is to take air samples and compare them with deep-water samples. However, you can’t collect historical samples of air. Instead, scientists have taken a small core sample from the tree to look at the tree’s rings.
“When plants grow, they take carbon dioxide out of the air by photosynthesis and they use that to grow their structures. The carbon from the air ends up in the tree rings,” scientist Jocelyn Turnbull explained.
Thwaites Glacier, Antarctica. Photo: Wikipedia
Thwaites Glacier retreating faster than ever
Doomsday Glacier deteriorates: The ‘Doomsday Glacier’ is the name often given to the Thwaites Glacier in Antarctica. New data from underwater robots and sea mapping show that the glacier is deteriorating faster than ever.
Underwater maps reveal periods of rapid retreat in the last few centuries, but climate change is accelerating this. It is now losing 50 billion tonnes of ice each year, twice the amount of 30 years ago.
The underwater camera showed a ridge in the sea floor that has been propping up the glacier. Along the ridge, there are 160 parallel grooves. The glacier left these ridges behind at high tide. Each day, the high tide lifted the glacier and it edged slightly further inland.
“It’s as if you are looking at a tide gauge on the seafloor, it blows my mind how beautiful the data is,” said oceanographer Alastair Graham.
From the ridges, scientists have calculated that the glacier is retreating three times faster than it did between 2011 and 2019.
