New Scientist

The devoted spider dads who fix up nurseries for their babies

Most male spiders bail out after mating – if they make it through the process alive, that is, as females of many spider species cannibalise their mates.

But not this spider. Male Manogea porracea in South America not only help with childcare, they often end up as single dads. Read more in New Scientist.

Sword-slashing sailfish hint at origins of cooperative hunting

Cooperation makes it happen. Sailfish that work together in groups to hunt sardines can catch more fish than if they hunt alone, even without a real coordinated strategy.

To catch their sardine dinner, a group of sailfish circle a school of sardines – known as a baitball – and break off a small section, driving it to the surface.

They then take turns attacking these sardines, slashing at them with their long sword-like bills, which account for a quarter of their total length of up to 3.5 metres. Knocking their prey off-balance makes them easier to grab.

These attacks only result in a catch about 25 per cent of the time, but they almost always injure several sardines. As the number of injured fish increases, it becomes ever easier for everyone to snag a meal. Read more in New Scientist.

Chimps and bonobos interbred and exchanged genes

Chimpanzees and their relatives bonobos are closer than we thought. Bonobos seem to have donated genes to chimps at least twice in the roughly two million years since they last shared an ancestor.

The two closely related apes have occasionally interbred in captivity, and bonobos are renowned for their free and easy sex life. But the finding that they interbred in the wild was unexpected. Read more in New Scientist.

Islands to lose fresh water as rising seas sink them from within

Small island nations are among the countries most at risk from climate change, as rising sea levels threaten to swamp them and make their fresh water salty.

But they face another danger – the rising seas will cause them to lose their fresh water by pushing it above ground, where it gets evaporated. Read more in New Scientist.

Endangered frog recovers thanks to resistance to deadly fungus

For decades a deadly fungus has been slaughtering amphibians around the world, driving many to the brink of extinction or even beyond.

But now one frog’s recovery shows that, with a little luck and habitat preservation, some amphibians may be able to evolve resistance to the fungusRead more in New Scientist.

Surfing on a turtle’s tail makes swinging crabs monogamous

Surfing the world’s oceans on the back of a turtle may sound like a life of luxury, but for a small crab it also means restricting itself to a single mate.

A species of small oceanic crab, Planes minutus often makes its home on the shells of loggerhead turtles. They tuck themselves into a tiny space above the turtle’s tail and below the shell, just the right size for a pair of crabs – a male and a female living in a simple monogamous relationship.

But these crabs will also make their homes on floating debris, where they nestle among stalked barnacles, and often enjoy a more swinging, polyamorous lifestyle. Read more in New Scientist.

Rattlesnakes silently shook their tails before evolving rattles

Shake, rattle and strike. It is possibly one of the most terrifying sounds in the animal kingdom, but how the rattlesnake evolved its chilling warning signal is a mystery. Now a study suggests the rattle evolved long after the tail-shaking behaviour.

The evolution of the rattle has baffled scientists because, unlike other complex physical traits like eyes or feathers, it has no obvious precursor or intermediate stage.

“There is no half-rattle,” says David Pfennig at the University of North Carolina at Chapel Hill. Read more in New Scientist.

Hawaiian crows can use sticks as tools but are nearly extinct

It’s certainly something to crow about. New Caledonian crows are known for their ingenious use of tools to get at hard-to-reach food. Now it turns out that their Hawaiian cousins are adept tool-users as well.

Christian Rutz at the University of St Andrews in the UK has spent 10 years studying the New Caledonian crow and wondered whether any other crow species are disposed to use tools.

So he looked for crows that have similar features to the New Caledonian crow – a straight bill and large, mobile eyes that allow it to manipulate tools, much as archaeologists use opposable thumbs as an evolutionary signature for tool use in early humans.

“The Hawaiian crow really stood out,” he says. “They look quite similar.” Read more in New Scientist.

Are we ready for the gold rush on the sea floor?

One firm reckons its planned sea-floor mines are more sustainable than those on land. But the diggers could destroy rare life and more.

THE submersible Alvin encountered its first “black smoker” 2000 metres deep off the coast of the Galapagos Islands. It was 1977, and the realisation that life could survive in pitch darkness next to deep sea hydrothermal vents was about to stun the world. Now we are returning to those vents, this time on the other side of the Pacific – and armed with diggers.

The hot water shooting out of these vents contains all sorts of dissolved precious metals. On contact with the cold ocean water, these immediately precipitate out, showering the vicinity with gold, silver, copper and more. Some want to tap into this booty, arguing that deep sea mining is not only lucrative, but also a more sustainable alternative to mineral extraction on land. But not everyone is convinced we can exploit the deep without damaging it. Read more in New Scientist.