Science: how bird flocks stay in formation

Few aerial sights beat the beauty and elegance of a flock of birds flying across the sky in a V-shape, but how they maintain the formation has remained something of a mystery. Now a remarkable study of migrating ibises has demonstrated that individual birds fly in positions that derive maximum aerodynamic benefit from their companions’ wingbeats.

Using the latest lightweight tracking technology, researchers at the Royal Veterinary College have shown for the first time how birds capture as much “upwash” or “good air” as possible from their neighbours throughout their flap cycle, while avoiding areas of downwash or bad air.

Scientists have long suspected that V-flying – favoured particularly by geese, ducks and other waterbirds – gives aerodynamic advantages over flying in a straight line or in a disordered flock like pigeons. But until this RVC ibis study, published in Nature, they had not realised how well birds could handle the complex flight dynamics and sensory feedback required for aerodynamic optimisation.

The researchers were able to monitor flight patterns so intensively because their flock of northern bald ibises was used to flying alongside a microlight aircraft. This critically endangered species is just hanging on in parts of the Middle East and north Africa but died out in Europe 300 years ago. An Austrian conservation body called Waldrappteam is working to reintroduce them by hand-rearing birds in Vienna and training them to follow a microlight mother ship to their historic breeding grounds in Italy – a path they would once have learnt from adult birds.

The study followed a group of 14 young bald ibises en route from Austria to Tuscany, tracking the precise wingbeat and position of each bird using a lightweight backpack including GPS and inertial measurement devices.

Just 100,000 years ago, what is now the eastern Sahara desert held a huge lake, 45,000 sq km in area, formed by natural damming of the White Nile river, according to research at Exeter university.

“The intricate mechanisms involved in V-formation flight indicate remarkable awareness and ability of birds to respond to the wingpath of nearby flock-mates,” says Steve Portugal, lead researcher. “Birds in V formation seem to have developed complex phasing strategies to cope with the dynamic wakes produced by flapping wings.”

On average the ibises fly about 1.2m apart. They alternate in the position at the tip of the V, which requires the most stamina because it does not benefit from any upwash.

The study leaves many questions unanswered. How, for example, do the ibises sense their best flying position and wingpath: by watching the bird in front and matching its beats, or by sensing the air flow with their wings? Clearly, however, since the juvenile ibises had no adults to learn from, their V-flying behaviour must be self-taught. The longer they followed the microlight, the better their formation.

——————————————-

The changing face of British science

Who are Britain’s scientific leaders? Many people see them as senior researchers and academics, mainly male, running scientific bodies such as the Royal Society.

In an attempt to challenge this “narrow and old-fashioned view of science”, the Science Council, an umbrella organisation for learned societies and professional bodies across British science, has drawn up a new – and rather different – list of the country’s “100 leading practising scientists”.

For a start, 40 of the 100 are women.

By contrast, the fellowship of the Royal Society, the national academy of sciences, is 6 per cent female. There are also seven scientists from ethnic minorities on the list. But the point of the exercise is not so much to highlight gender and ethnic diversity as to show how many different types of scientist are working in different roles.

Diana Garnham, chief executive of the Science Council, says modern Britain has a “collective blind spot”, seeing scientists either as “dead people” or “academics and researchers”. “It is vital that this narrow vision is challenged because it is inhibiting education policy, the career ambitions of young people and investment in developing the skills we need to deliver a world-class economy.”

To help compile the list, the council asked its member organisations for nominations. To paint a broad picture, it also identified “10 types of scientist” ranging from explorer and investigator to entrepreneur and policymaker.

The list still includes many of the “great and the good”, such as astronomer Dame Jocelyn Bell Burnell, biotech entrepreneur Sir Chris Evans and other titled figures. But there are less familiar names too.

“We went for the people who other scientists look to for advice and leadership,” says Garnham.

www.sciencecouncil.org

——————————————-

A formula that could predict conflicts

By studying the development of different types of human conflict, scientists at the University of Miami have come up with a formula for working out when future attacks, such as those committed by terrorists and cyber criminals, are likely to occur, writes Sarah Spickernell.

Neil Johnson and his team looked at the severity of attacks for each conflict analysed and at the time intervals between those attacks. Based on this information, they came up with a formula to predict events, whether applied to a war, cyber crime or simply a baby vying for its parent’s attention.

“For so long people have been confused by what goes on in a conflict but it actually follows a hidden order,” says Johnson. “And it doesn’t hold true for just one conflict – it can be applied irrespective of the size of the conflict or why it is taking place.”

The formula predicts that on average the severity of individual attacks does not change throughout a conflict but that the frequency with which they occur varies according to a “red and blue” model – a term first coined by the military to describe a smaller, more agile red force repeatedly attacking a larger and more sluggish blue one. Prime examples of this model are the stealthy hacking of governmental information by cyber criminals and a small group of protesters acting aggressively towards an authoritarian government.

The study, published in Nature, reveals a type of arms race. “At the beginning of a conflict, things speed up as the attacker becomes more proficient …but then the attacks slow down as the blue becomes more capable of evading attacks. What we are seeing is a two-sided adaptation and counter-adaptation, and this is important for understanding future conflicts,” explains Johnson.

He first identified the pattern in 2005, when he compared events in the long civil war between the Colombian government and guerrilla groups with those of the Iraq war. In nearly all the conflicts he has studied, the formula’s predicted time intervals have matched those occurring in reality.

Johnson believes that this finding has important ramifications. “We can shed light on perpetrators and identify intervention strategies,” he says.

“If we know when an attack is likely to occur, we can tighten up security and make sure we are as prepared as we can be, whether it’s for a terror attack or a cyber attack.”

Exceptions to the rule were observed where conflicts involved sides similar in size and power, such as the world wars, or where one side was attacking a completely passive opposition, as in the case of a homicide or suicide.

There was also the occasional anomalous result for a red and blue conflict but in these instances Johnson believes a different attacker must be to blame. “When an attacker doesn’t follow the pattern, it is usually because you are, in fact, dealing with a new attacker – a new type of red. This in itself could prove crucial in identifying and stopping new threats to society before they have the chance to proliferate,” he says.