Science Links of the Week » Explorersweb

Our passion for the natural world drives many of our adventures. And when we’re not out and about, we love delving into discoveries about the places we live and travel. Here are some of the best natural history links we found this week.

Using silent electric bikes to catch poachers: African hunters can hear the noisy motorbikes usually used by the rangers. These can be heard two kilometers away and give hunters plenty of time to escape. So now rangers across the continent are starting to switch to silent off-road e-bikes.

The exact location of the bikes is a secret, but they are now in 127 parks across Africa. Bicycles are charged using solar energy in mobile charging stations. Thanks to this, the rangers have been quietly tracking them for weeks.

Bicycles can be used in plains, forests and jungles. Until now, hunting attempts against several duiker species have been abandoned. Although none of the small antelopes are endangered, they are vital prey for endangered predators.

Protecting beachgoers without killing sharks

Drones spot sharks that get too close to crowded beaches: The Australian state government of Queensland is testing a new shark safety program. For years, they relied on nets and drum nets to protect beachgoers from sharks.

These methods are effective, but also harmful. Last year, 958 animals were caught, including 798 sharks. Unfortunately, 70% of them died. Dolphins, dugongs and turtles also died in protective equipment.

So now camera-equipped drones are being used to monitor sharks. The drones fly at a height of 60 meters, and descend when the pilot detects a shark to identify the size and species. If a shark is a threat, the beach is evacuated while lifeguards control the animals from personal watercraft. An added bonus of drones is that they can drop life-saving equipment onto struggling beachgoers in the water.

Aerial image of sharks swimming near the shore

Photo: Shutterstock

Bear skins were the original key to northern survival

People used bear skins 320,000 years ago: Researchers have found bear bones in caves in Lower Saxony, Germany. The 320,000-year-old bones came from a Middle Pleistocene site in Schöningen.

Cut marks usually indicate that the animal was used for meat, but such marks are found on hand and foot bones. “There is almost no meat to recover from the bones of the hands and feet,” said paleontologist Ivo Verheijen.

On the contrary, the less fine and precise cut marks suggest a careful removal of the skin. This means that the ancient people of northern Europe used bearskins to survive the cold winters.

Bears’ winter coats are particularly thick because they need to keep the animals warm during hibernation. They have long outer hair and a dense, short undercoat. “The use of bear skins is probably a key adaptation of early humans to the northern climate,” said Verheijen.

Genital spines help male wasps survive: Male wasps do not have stingers that inject venom. Instead, they have a pair of spines that evolved with their reproductive system. Genital spines do not contain venom, but wasps use them to sting predators in the face.

But how much damage can these genital spines do? The researchers placed the wasps together with different species of frogs in a laboratory. With the frogs in the pond, the spinal holes did not help, and they ate all 17 wasps.

However, with tree frogs, the wasps used their spines to pierce the frog’s mouth. Although the spines do not cause serious damage, they cause enough pain to cause the surprised predator to drop or back away from the wasp.

A Bengal cat plays with a toy

Photo: Shutterstock

Of course, house cats are still pretty wild

When were cats first domesticated? Almost 10,000 years ago, humans settled in the Fertile Crescent, in the region around the Tigris and Euphrates rivers. Soon, hunter-gatherers became farmers, and cats became a form of pest control.

Other animals show multiple points of domestication, but DNA analysis supports the theory that this was the only location where cats were originally domesticated. Then, felines moved around the world with humans.

Another anomaly of cat domestication is that their behavior has changed much less than other animals. “We can actually consider cats semi-domesticated because, if released into the wild, they would likely hunt pests and survive, unlike dogs and other domesticated animals,” said feline geneticist Leslie Lyons.

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