STUNNING video shows an owl going through a cloud of tiny helium bubbles in ultra slow motion, revealing how birds stay up by creating small circular air currents under their wings
- Scientists from the Royal Veterinary College outside of London have studied bird flight
- They filmed two owls and a hawk as they flew through small helium bubbles
- The slow motion shot shows small air swirls that keep the birds up
A new study has captured the mechanics of how birds fly by creating small vortices or rotating air with their wing flaps and tail movements.
To study the aerodynamics of bird flight, a group of scientists from the Royal Veterinary College in Hatfield, England, just outside of London, registered three different species of birds flying through a specially designed escape route.
The birds selected for the study were a female barn owl, a male wood owl and a female northern hawk.
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Researchers from the Royal Veterinary College in Hatfield, England admitted two owls and a hawk as they flew through a fine mist of helium bubbles to study the aerodynamics of bird flight
The escape route was a little less than six feet long and six feet wide and was painted completely black to make the birds stand out.
The birds flew a short distance between two human handlers and passed through a fine mist of helium bubbles in the middle, which were illuminated with LED lighting as the birds passed, allowing the team to record the exact movement of the air produced by the bird wings.
The escape route was carefully assembled to prevent any movement of the air that could disturb the measurements, while the selected birds all had experience in brightly lit environments such as film sets.
As the birds flowed through the fog of helium bubbles, recordings were made by ultra slow motion cameras and an advanced 4D particle tracking program that allowed the team to measure the movement of each helium particle.
Interpreted the wake structure of the different birds to understand how they navigate and maneuver through the sky
The volume of helium bubbles was designed not to be illuminated with external lights until the birds had passed through.
They recorded the movement of the helium bubbles with cameras and an advanced 4D particle tracking software that could map the movement of each helium bubble.
The recordings showed that for each bird the wings produced two circular vortices, one clockwise and one counterclockwise, both giving lift to keep the birds up.
A second pair of smaller swirls were also created in the aftermath of the tail, which would rotate upwards if the tail was tilted upwards, or downwards if the tail was tilted downwards.
The team used ultra slow motion cameras and special 4D particle tracking software with which they could follow the movements of all helium bubbles while being swept into the circular air currents.
The team discovered that the birds produced two clockwise and counter-clockwise sets that helped keep the birds up
The blue stripes represent clockwise rotating air swirls and the red stripes represent counterclockwise rotating air swirls, and the central stripes represent the swirls produced in the aftermath of the bird’s tails
The team said their results are “not surprising and fully in line with expectations from aerodynamic theory and aviation experience.”
These four rotating air vortices helped each bird lift the required amount to stay in the air, while allowing subtle shifts to stay horizontal.
According to the study that was published this month in the Journal of Experimental Biology, the results are “not surprising and fully in line with expectations from aerodynamic theory and aviation experience.”
The team suggests that further research could help provide insight into the full stability mechanics that birds use during the flight, but the recorded airflow data suggests that the general principles of aerodynamics apply to birds, just as you would expect.
WHY DO MIGRANT BIRDS FLY IN A V FORMATION?
Birds fly in a V formation to help them fly more efficiently, staying up while using up as little energy as possible.
Scientists got to know the aviation secrets of migratory birds after attaching small logging devices to a herd of 14 northern bald ibises that not only tracked their position and speed via satellite, but also measured each flap of their wings.
The 14 birds used in the study were raised by hand at the Vienna Zoo in Austria by the Waldrapp team, an Austrian protection group reintroducing northern bald ibeses into Europe.
Birds fly in a V formation to help them fly more efficiently, stay up while using up as little energy as possible (stock image)
The birds were studied while flying alongside an ULM on their migration route from Austria to their winter home in Tuscany, Italy.
Principal investigator Steve Portugal, of the Royal Veterinary College, University of London, said: “The distinctive V-formation of bird flocks has long intrigued researchers and continues to attract both scientific and popular attention, but a definitive report of the aerodynamic implications of these formations has reached remained elusive until now.
“The complex mechanisms involved in the V formation flight point to a remarkable awareness and the ability of birds to respond to the wingpath of nearby mates. Birds in V formation appear to have developed complex phasing strategies to cope with the dynamic waking of flapping wings. “
When flying in a V formation, the wing flaps of the birds were about “in phase,” meaning that all wing tips followed roughly the same path, the scientists found.
This helped every bird catch extra lift from the upwash of his neighbor at the front.
Occasional shifts in position within the formation meant that birds sometimes flew directly after each other.
When this happened, the birds changed their wing strokes to an out-of-phase pattern to prevent them from being caught by downwash.