Using custom-built GPS and inertial measurement devices attached to free-flying birds on migration, researchers have gained ground-breaking insights into the mysteries of bird flight formation.
The research, led by the Royal Veterinary College, University of London, proves for the first time that birds precisely time when they flap their wings and position themselves in aerodynamic optimal positions, to maximise the capture of upwash, or ‘good air’, throughout the entire flap cycle, while avoiding areas of downwash or ‘bad air’. It was previously not thought possible for birds to carry out such aerodynamic feats because of the complex flight dynamics and sensory feedback required.
Lead researcher, Steve Portugal says the distinctive V-formation of bird flocks has long intrigued researchers and continues to attract both scientific and popular attention; however, a definitive account of the aerodynamic implications of these formations has remained elusive until now.
“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 Dr Portugal. "Birds in V-formation seem to have developed complex phasing strategies to cope with the dynamic wakes produced by flapping wings.”
The mechanisms that the birds use is achieved firstly through spatial phasing of wing beats when flying in a spanwise (‘V’) position, creating wing-tip path coherence between individuals which will maximise upwash capture throughout the entire flap cycle.
Secondly, when flying in a streamwise (‘behind’) position, birds exhibit spatial anti-phasing of their wing beats, creating no wing-tip path coherence and avoiding regions of detrimental downwash. Such a mechanism would be available specifically to flapping formation flight.
Scientists captured the data for the study as the birds flew alongside a micro-light on their migration route from their summer birthplace in Austria to their wintering grounds in Tuscany, Italy. The study is the first to collect data from free-flying birds and was made possible by the logging devices custom-built at the Structure and Motion Laboratory at the Royal Veterinary College.
The lightweight, synchronised, GPS and inertial measurement devices, recorded with 30cm accuracy where a bird was within the flock, its speed, and when and how hard it flapped its wings. The precision of the measurements enabled the aerodynamic interactions of the birds to be studied at an unprecedented level of complexity.
The instrumentation was developed with funding from the Engineering and Physical Sciences Research Council.
Life-saving drones
In the not too distant future, you may hear the hum of a drone's rotors as it descends upon you and be filled with a sense of relief, not panic. After all, it's coming to save you, not harm you.
Research at the University of Cincinnati (UC) could soon enable unmanned aerial vehicles, not dissimilar to the military drones patrolling the skies of Afghanistan, to track down missing persons on search-and-rescue missions, to penetrate curtains of smoke during wildfire suppression or possibly even to navigate urban landscapes on delivery runs for online retailers like Amazon. And it all could be done autonomously with a human acting only as a supervisor.
"Drones have gotten a very bad rap for various reasons," says UC's Professor Kelly Cohen. "But our students see that unmanned systems can have a positive impact on society."
For now, the US Federal Aviation Administration (FAA) greatly limits the use of drones. Cohen predicts that in the next few years FAA guidelines will adapt to this technology, and he believes disaster management and public safety officials such as firefighters and police will be among the first to be licensed to operate drones in US national airspace.
Ray of hope for magazines in the digital era
While print media continue to suffer at the hands of their online counterparts, new research from the University of Toronto Scarborough (UTSC) finds that print magazines with companion websites are able to attract more advertising.
"Targeting is as important as ever," says UTSC's Professor Ambarish Chandra. In a study of magazines in Germany, Professor Chandra and Professor Ulrich Kaiser of the University of Zurich found that magazines offering targeted advertising both in print and on the web can improve their advertising revenues.
Magazines create interest around a specific topic, which attracts readers with similar interests. The more homogeneous the magazine's audience, the more attractive it is to advertisers looking to target a specific type of consumer.
And it turns out people who get their information from more than one medium - 'multihomers', as Chandra and Kaiser call them - are particularly appealing to advertisers.
"You would think that advertisers would rather go after people who consume media from one source," says Chandra. Such people would be easier to find and to track.
But it turns out that the multihomers are more likely to see a brand's message more than once. "If they can reach you via print and online it's more likely that they can convince you to buy the product," says Chandra.
Magazines with websites will have the advantage over those that don't, because they will attract a homogeneous, targeted audience that will also be getting their information through more than one format. Such magazines can therefore charge more for their advertising space.
"It's very clear that circulation of print magazines in all markets has declined because of competition from the internet," says Chandra. "Magazines have to figure out how to embrace and integrate their print products with digital."
Quite so!
Les Hunt
Editor