In their quest for perpetual flight, researchers at Lehigh University have taken note of the turkey vulture’s amazing ability to stay aloft indefinitely with very little effort, as it scans the terrain beneath it for carrion to feed on. In addition to gauging thermals and wind direction with their own sensors, it appears that turkey vultures closely monitor other birds of prey in the area and use the information gleaned from them to determine which areas would best support their effortless soaring. It is thought that they may even keep an eye on the movement of clouds and the swaying of trees to gather information about wind currents and thermals.
Also of interest to aviation researchers, is the turkey vulture’s unique ability to hold its wings in a shallow V-shaped angle for extended periods of time which allows it to stay aloft with little effort, as well as giving it the ability to use sidewinds to its advantage, converting them into speed and altitude at a moment’s notice.
The concept of ‘dynamic soaring’ was first described in the British journal Nature in 1883 by Lord Rayleigh in an article entitled The Soaring of Birds. There he states that a bird cannot maintain its level indefinitely, either in still air or in a uniform horizontal wind, without working his wings. He concluded that if a bird maintained his course for some time, without working his wings, the conclusion can be drawn that either: The course is not horizontal; the wind is not horizontal; or the wind is not uniform – the latter being the principle relating to dynamic soaring.
Turkey vultures, also known as turkey buzzards, or simply buzzards, have a wide range of habitat, being found from southern Canada right down to the southernmost point of South America. These large scavengers favor open and semi-open terrain where they can spot their next meal with ease, feeding almost exclusively on carrion. They roost in large groups, nesting in caves, thickets, or hollow trees. As they do not have a syrinx, they can only make grunting and hissing noises. Legally protected in the United States, and with very few natural predators, turkey vultures have an IUCN conservation status of ‘least concern’.
With their forked tails and scythe-shaped wings, swifts herald the arrival of spring in Europe and are seen as the bringers of rain in parts of Africa where they spend their winters. These amazing birds spend almost their entire lives in flight, so much so that their legs are small and too weak to support them for long when perching, explaining why their family name, Apodidae, is taken from the Greek word meaning ‘without feet’. Spine-tailed swifts, also known as white-throated needletails, have been measured as flying up to speeds of 105 mph (169km/h), while common swifts are known to routinely reach speeds of 70 mph (112 km/h).
Although they resemble swallows, swifts are placed in the same order as hummingbirds, Apodiformes, while swallows are of the order Passeriformes. Their similarities are attributed to convergent evolution, a phenomena where differing species develop similar traits due to lifestyle adaptations, in this case their habit of catching insects in flight.
Distances are immaterial to swifts, as they can easily fly 500 miles in a day. Most swifts remain airborne from when they fledge to the first time they breed – a period of roughly four years. It’s been estimated that in a swift’s lifetime it will cover a distance of around 1.28 million miles. They even roost on the wing, circling gently for hours as the two sides of their brains take turns in sleeping. Swifts only nest to raise their young, and are fond of doing so inside roofs of houses. Parents can gather and carry as many as 1,000 insects to feed their young, making them very effective insect controllers. When the fledglings leave the nest, they all take to the skies and so the cycle continues.
When swifts are feeding in the late afternoon, they swoop through the air in a series of aerobatics that are fascinating to watch. As is the case with hummingbirds, swifts are able to rotate their wings in a manner that keeps them fully extended and rigid, delivering power on both the upstroke and downstroke, thereby increasing their speed and maneuverability. No other bird species are able to do this. So if you happen to have the good fortune to see swifts in action, take some time to appreciate their unique characteristics.
Flying into glass windows they are unable to see is one of the leading causes of bird deaths in urban areas. So the invention of a glass coating which is visible to birds, while remaining transparent to humans, is welcome news. Developed by German company Arnold Glas the new product, named Ornilux, reflects ultraviolet light which birds can see, but humans cannot. Tests conducted thus far suggest that its use may reduce window-related bird strikes by 66-68%, and with ongoing efforts to improve the product, this percentage may very well be increased.
The glazing concept was inspired by the web of the Orb-weaver spider which is known to reflect ultraviolet light preventing birds from flying into it and destroying it. Upon reading an article about the Orb-weaver spider, a friend of the owner of Arnold Glas suggested using the concept to develop a coating for glass, for the same purpose as the spider has – to prevent birds from flying into it. The product development took a number of years, with a host of glass and coatings being tested and discarded, until developers discovered a coating they named Mikado – the German name for the game of pick-up-sticks, as its pattern resembles the scattered sticks.
The end product was tested at a flight tunnel situated in a US nature reserve, where birds were encouraged to fly to the end of the tunnel which had been partly covered in glass coated with Ornilux and partly with plain glass. A net was used to catch birds that fell and great care was taken to ensure that none were injured. As mentioned earlier, the results of the test revealed that the product could prevent up to 68% of bird strikes.
The coated glass has recently been installed in a lookout tower at Lindisfarne on the north-east coast of England – the first application of the new product in the UK. The lookout tower dates back to the 1940s when it was used by the local coastguard for the benefit of local fishermen. Having stood empty for some years, it has recently been renovated for use by visitors to the island as it offers spectacular views of the surrounding areas and its wildlife. Safety for the thousands of birds that live in the area, or stop-over at certain times of the year, was a major consideration, and Ornilux provided the solution.
While the cost of the product may prevent it from being used on a wide scale at this stage, it is early days yet and future developments may well make it more affordable. Meanwhile Ornilux offers a solution to the problem of birds colliding with glass, and has been installed at a wildlife center in Canada, a mountain railway building in Austria, a zoo in Germany and a school in the United States, as well as the lookout tower at Lindisfarne.
Covering more than 24 hectares, with more than four thousand birds representing 675 species from all around the world, Weltvogelpark Walsrode is a birding enthusiast’s paradise. Promoted as the largest bird park in the world, both in land area and number of species, Weltvogelpark is located near the town of Walsrode in Lower Saxony, Germany. The park is celebrating its 50th anniversary in 2012 with a host of events and special displays, one of which is more than three million spring flowers – a picturesque palette of vibrant color.
With special emphasis on conservation, Weltvogelpark offers an outing that is both entertaining and educational. The walk-in free-flight aviaries allow visitors to observe the birds in their natural habitat, while flight demonstrations demonstrate the amazing skills of birds, and feeding times provide insight into the needs of various species, including pelicans, penguins, vultures and flamingoes. The park offers special events and classes for school groups, while ensuring that visitors of all ages and levels of mobility have access to the features of the park. Experienced rangers are on hand for guided tours, and boards detailing interesting facts about the Weltvogelpark’s feathered residents are placed throughout the spacious reserve.
The park is also involved in research and conservation projects, and has had a measure of success in breeding some endangered species, including the Andean condor (Vultur gryphus), and Shoebill stork (Balaeniceps rex). While breeding is generally allowed to take its natural course at Weltvogelpark, sometimes it is necessary to intervene, particularly with rare and endangered species. In these cases the eggs are artificially incubated and the birds are hand-raised, ensuring that they bond with their own species as soon as possible to avoid being imprinted by humans. In 2011 more than 600 young birds hatched out – clearly they are happy in their environment.
In addition to the outstanding facilities for the park’s birds, Weltvogelpark Walsrode boasts one of the largest botanical gardens to be found in Northern Germany. More than 70 species of roses and 120 different species of rhododendron are features of the botanical gardens, with hundreds of different trees, flowers and shrubs, both indigenous and exotic, providing color throughout the year.
A study run by the University of Montana might just be able to bring clarity to the evolution of flight, as Brandon Jackson and his team conducted research into bird flight. Their findings have recently been published in the Journal of Experimental Biology. The art of flap-running by birds is the major factor discussed in the study, showing that this method could have been used by once flightless birds, and is still used by birds today to enable them to propel themselves forward. Jackson wanted to know why.
It seems that birds today will often flap their wings while walking up a slope or incline, to enable them to move forward. It is believed that this flap-run movement enables birds to take to flight. It is the same technique that is adopted by chicks, as they are unable to fly when they are born, and need to learn how to conquer this method of movement. The fact that birds are not born with flight abilities, has led researchers to believe that this very method was part of the evolution of flight. This interesting method of movement was noticed by Ken Dial while he was studying chuckars, which are part of the partridge family. After talking to locals and ranchers who have constant contact with these birds, they confirmed that most of the chuckars would rather flap-run up a hill or cliff, as it seems that it takes a lot less energy for them to flap-run instead of flying. This became very intriguing to researchers and they decided to measure how much power is being used while flap-running as opposed to flying.
They managed to record this by implanting electrodes into pigeons’ flight muscles, which could then record the muscle activity. Pigeons are very good flyers, but given inclines and ramps, the difference between flying up the incline and flap-running was analyzed. It was found that much less power was used during flap-running and that this method would therefore be crucial for chicks to learn how to fly, as well as for birds that are still developing their plumage to escape predators. This study has not only given the researchers new insight into birds but a glimpse back into the evolution of flight.