Gorillas learn to play fair by playing tag

There's more to an innocent game of tag than meets the eye. When gorillas play the playground favourite, it teaches them a valuable life lesson about unfairness, social boundaries and retaliation. That, at least, is the conclusion of the first study to observe the primates' reactions to inequity outside a controlled laboratory setting.

Young gorillas often engage in play fights that resemble what children do in a game of tag: one youngster will run up to another and hit it, then run away. The other gorilla then gives chase and hits the first one back (see video, above).

Marina Davila-Ross of the University of Portsmouth, UK, and colleagues studied video footage of six groups of gorillas in zoos. Twenty-one juveniles – both males and females – were observed chasing one another in a total of 86 games.

They found that the gorilla that did the hitting almost always moved to run away before its victim started moving. The researchers argue that this means the hitter is expecting retaliation and has therefore learned something about acceptable social behaviour.

It was a different story, however, when the gorillas played the game more gently, grabbing each other rather than hitting. Then the "grabber" was not the first to run – perhaps because the gorillas saw the gentler act as less aggressive. "Apes use play to explore the ramifications of unfair social situations," says Davila-Ross.

Heart of darkness could explain sun mysteries

IS DARK matter lurking at the centre of our bright sun? Yes, say two research groups who believe the elusive stuff is cooling the solar core.

The insight doesn't significantly affect the sun's overall temperature. Rather, a core chilled by dark matter would help explain the way heat is distributed and transported within the sun, a process that is poorly understood.

Dark matter doesn't interact with light and so is invisible. The only evidence for its existence is its gravitational effects on other objects, including galaxies. These effects suggest dark matter makes up about 80 per cent of the total mass of the universe.

The idea that it might lurk at the heart of the sun goes back to the 1980s, when astronomers found that the number of ghostly subatomic neutrinos leaving the sun was only about a third of what computer simulations suggested it should be. Dark matter could have explained the low yield because it would absorb energy, reducing the rate of the fusion reactions that produce neutrinos.

However, the problem was solved another way when it was found that neutrinos oscillate between three kinds, only one of which was being detected on Earth. As a result, the idea of solar dark matter was dropped.

Now it is being resurrected in the light of recent searches for dark matter, which have put limits on the mass of the particles that it is made of and shown that it interacts only very weakly with ordinary matter. These led Stephen West of Royal Holloway, University of London, and his colleagues to explore what would happen if particles that fell within these limits exist in the sun.

Their simulations show that gravity would pull such dark particles to the centre of the sun, where they would absorb heat. Some of these dark matter particles would then carry this heat from the core to the surface, decreasing the core temperature

Let there be night, for wildlife's sake

IT IS time to take back the night for wildlife. That was the rallying call from a landmark session on light pollution at the Society for Conservation Biology .

The disruptive effects on animals of our penchant for bright lights has rarely impinged on public consciousness. Notable exceptions are when turtle hatchlings head inland to the bright lights of a beach resort instead of the safety of the moonlit sea, or birds collide en masse with brightly lit buildings.

It is rapidly becoming clear, though, that light pollution subtly interferes with the growth, behaviour and survival of many nocturnal species - not just those that hit the headlines.

The threats posed by the humble street lamp do not rival the wholesale destruction of tropical forests and other habitats, or indeed the threat of climate change. But participants in the session at the Edmonton meeting agreed that planners should spare a thought for wildlife when installing lighting. "We've taken away the night," warns Travis Longcore of the University of Southern California in Los Angeles, who chaired the session.

For instance, Emma Stone of the University of Bristol, UK, has shown that high-pressure sodium street lights can divert lesser horseshoe bats from their usual routes between roosts and foraging grounds. Such diversion may be energetically costly - all the more of a worry as the bats in the study were pregnant.

Fluorescent felines

The fluorescent cat on the left, whose skin glows in ultraviolet light, is one of two created at Gyeongsang National University in Jinju City, South Korea, in 2007.

The gene for the fluorescent protein was added to skin cells, which were then cloned by transferring their nucleus to empty eggs.

The cats were a practice run; using fluorescent proteins make it very obvious when animals have been successfully modified.

Gulf turtle evacuees could get lost at sea

Turtles are being relocated from the US Gulf coast to save them from the Deepwater Horizon oil spill – but this may scramble their navigating skills, marine biologists warn. As a result, the animals could lose their way to their nursery grounds.

The turtles – mostly threatened loggerheads, as well some endangered Kemp's ridley, green and leatherback turtles – use the Earth's magnetic field to navigate often hazardous migration routes. They travel from their birthing beaches of Florida and Alabama to the open sea and then on to their nursery grounds around the Azores and Canary Islands, where they live for years before returning to their home beaches to nest as adults.

The first batch of evacuated sea turtles, rescued as eggs from the oil-drenched Florida Panhandle and Alabama beaches, to hatch at Kennedy Space Center in Florida were released into the Atlantic Ocean on Saturday. The evacuation was part of a campaign spearheaded by the US Fish and Wildlife Service to move all Gulf coast turtles' eggs – there are at least 50,000 – from their native breeding grounds to the unaffected Atlantic shores of Florida.

The eggs are being evacuated 50 to 53 days after laying, in the final stages of their 60-day incubation. Immediately after hatching they will be released along Florida's Atlantic beaches. But some researchers are warning that releasing Gulf coast turtles straight onto the sand on the other side of Florida could interfere with their navigational skills.

Air pollution

Air pollution doesn't just make it hard to breathe – it may also increase the risk that people will take their own lives.

A new study in seven cities across South Korea has uncovered a clear association between suicide and spikes of particulate pollution. Meanwhile, researchers who in the 1990s linked air pollution to asthma in a large group of Taiwanese children have now found that those with the condition were subsequently more likely to have killed themselves.

Suicide is a big problem for South Korea, where the rate per 100,000 people rose from 14 in 1996 to 23 in 2006 – the largest increase in the developed world.
Soot and suicide

To examine the role of pollution, researchers led by Chang Soo Kim of Yonsei University in Seoul linked records of more than 4000 suicides to measurements of PM10 – airborne particles with a diameter of 10 micrometres or less, which include the soot from vehicle exhausts.

Kim's team found that suicides were more common in the two days following a spike in pollution. They considered PM10 measurements on a scale from the highest and lowest levels recorded, calculating that people were 9 per cent more likely to kill themselves following a spike in pollution rising across the middle 50 per cent of recorded values. For people with cardiovascular disease, which has already been linked with particulate pollution, the increase was almost 19 per cent.

South Korea's cities, like many in Asia, are badly blighted by air pollution, and it is unclear whether the effect would be so dramatic in cities that have tighter pollution controls. "Further investigations of low-level exposure to particular matter are needed," says Kim.

Grow-your-own approach to wiring 3D chips

When the island of Manhattan became too crowded, architects responded by building skyscrapers. The increasing density of components on "flat" computer chips is encouraging similar ideas, building upwards to create three-dimensional chips. But moving from flat interconnecting wires to 3D ones to link up different "storeys" has proved a tricky business – until now.

Instead of soldering prefabricated wires in place, as is traditionally done to connect two parts of a chip, Min-Feng Yu and Jie Hu at the University of Illinois at Urbana-Champaign have developed a technique to grow tiny 3D wires in situ which are tailor-made for their location.

Yu and Hu's technique is a modified form of electroplating, in which an electric current is used to coat a conductive surface with a thin layer of metal, deposited from a liquid electrolyte. Such a technique theoretically offers a way to directly "write" metal wires onto a surface.

Super goby helps salvage ocean dead zone

A resilient fish is thriving in an inhospitable, jellyfish-infested region off Africa's south-west coast. And crucially it is helping to keep the local ecosystem going, and to preserve an important fishery.

The Benguela ecosystem lies off the coast of Namibia. It exists in waters only 120 metres deep that used to be a rich sardine fishery, but in the 1960s the sardine population crashed because of overfishing and environmental factors, and the region was invaded by algal blooms and swarms of jellyfish.

The algae have used up almost all the oxygen in the water, leaving the bottom half with oxygen levels below 10 per cent, far too little for most sea creatures. At about 80 per cent, levels are almost normal in the upper waters – but those regions are thick with jellyfish and algae, and therefore unwelcoming to most other life.

What's more, when the algae die they sink to the bottom and decay, releasing large quantities of the poisonous gas hydrogen sulphide. Nevertheless, local fish called bearded gobies have flourished in Benguela. Until now, nobody has understood how they survive it.