New Scientist

Wise elk learn to outsmart hunters and tell apart their weapons

As female elk get older, they also get wiser: they learn how to avoid getting shot by hunters, and appear to adapt their behaviour to the types of weapon the hunters carry.

Hunting by humans is known to affect how elk behave, selecting for more cautious behaviours by killing more of the bolder animals. But ecologist Henrik Thurfjell at the University of Alberta, Canada, wondered whether the animals might also learn how to stay safe as they age. Read more in New Scientist.

Monkey mafia steal your stuff, then sell it back for a cracker

Long-tailed macaques living near an Indonesian temple have figured out how to run a ransom racket on visiting tourists.

The monkeys grab valuables, such as glasses, hats, cameras or, in one case, a wad of cash from the ticket booth, then wait for temple staff to offer them food before dropping their ill-gotten gains and dashing off with the tasty prize. Read more in New Scientist.

Snowball Earth melting led to freshwater ocean 2 kilometres deep

A little more than 600 million years ago, you could have drunk from the ocean.

After an extreme ice age known as snowball Earth, in which glaciers extended to the tropics and ice up to a kilometre thick covered the oceans, the melt formed a thick freshwater layer that floated on the super-salty oceans. Read more in New Scientist.

Isolated crayfish are more resistant to the effects of alcohol

For crayfish at least, a more sociable life makes booze work quicker. When crayfish were put in water containing a little alcohol, the ones who had been kept on their own over the preceding week took longer to show signs of alcohol exposure – such as tail flips – than those who had been living with others of their kind. Read more in New Scientist.

Oldest tooth filling was made by an Ice Age dentist in Italy

Scared of the dentist? Be glad you don’t live in the Ice Age. A pair of 13,000-year-old front teeth found in Italy contain the earliest known use of fillings – made out of bitumen.

The teeth, two upper central incisors belonging to one person, were discovered at the Riparo Fredian site near Lucca in northern Italy.

Each tooth has a large hole in the incisor’s surface that extends down into the pulp chamber deep in the tooth. “It is quite unusual, not something you see in normal teeth,” says Stephano Benazzi, an archaeologist at the University of Bologna. Read more in New Scientist.

US bill restricts use of science in environmental policymaking

The US Environmental Protection Agency (EPA) is facing a future in which its hands will be tied on making many policies if a new bill becomes law.

Last week the US House of Representatives passed a bill, the HONEST Act, that would prevent the EPA from basing any of its regulations on science that is not publicly accessible – not just journal articles themselves, but all of the underlying data, models and computer code. Read more in New Scientist.

Flying foxes are facing extinction on islands across the world

Flying foxes are in deep trouble. Almost half the species of this type of fruit bat are now threatened with extinction.

The bats face a variety of threats, including deforestation and invasive species, but the main one is hunting by humans, says Christian Vincenot, an ecological modeller at Kyoto University in Japan, who highlights their plight in a perspective article in Science this week. Read more in New Scientist.

Dogs use deception to get what they want from humans (a sausage)

Dogs are all honest, loyal and obedient, right? Well, not always. Our pets can be sneaky and manipulative when they want to maximise the number of tasty treats they get to eat.

Marianne Heberlein, who studies dog cognition at the University of Zurich in Switzerland, wanted to test the animals’ ability to use deception to get what they want from humans. Read more in New Scientist.

Snow will melt more slowly in a warmer world – here’s why

As global temperatures rise, snow will melt more slowly. Yes, you read that right – more slowly.

Warmer global temperatures will lead to less snow in many mountainous areas, says Keith Musselman, a hydrologist at the National Center for Atmospheric Research in Boulder, Colorado.

That thinner layer of snow will be less likely to last into the late spring and early summer, when melting rates are highest. Instead, it will melt slowly throughout the winter and early spring, when night-time temperatures are lower and there is less direct sunlight, releasing just a trickle of water instead of a sudden gush. Read more in New Scientist.

Why grey wolves kill less prey when brown bears are around

Wolves may be better at sharing their meals with bears than we thought.

Biologists have long assumed that when wolves and brown bears share territory, the wolves are forced to kill more often to make up for the food stolen by scavenging bears.

But when Aimee Tallian, a biologist at Utah State University, and her colleagues looked for evidence of this, they found the opposite. Where wolves live alongside bears in Scandinavia and Yellowstone National Park in the US, they actually kill less often. Read more in New Scientist.