Tag Archives: pigeons

Flying ‘Robotic pigeon’ brings us closer to bird-like drones

Strong and muscular fliers, pigeons are naturally suited to handle the blowy winds between buildings in large cities. That’s why engineers have now turned to them for inspiration, adding pigeon flight feathers to an airborne robot called PigeonBot.

Credit Standford University.

The robotic pigeon integrates true elements of traditional flying machines with elements of biology. David Lentink and colleagues at Stanford University didn’t try to build a machine to act like a bird, which would have been highly challenging. Instead, they closely studied biological mechanisms to learn how birds fly.

“I really wanted to understand how birds change the shape of their wings,” said David Lentink to Popular Science, an assistant professor of mechanical engineering at Stanford and a co-author on a new study which was published in the journal Science Robotics.

Credit: Lentink et al.

Lentink and the team studied common pigeons, looking at their skeletons and feathers. They discovered that the birds control the flight through about 40 feathers, using four “wrist” and “finger” joints to steer their movements. With that knowledge, they recreated the same mechanisms but in a drone driven by propellers.

Image credits: Chang et al (2019) / Science Robotics.

The drone’s body is formed by a foam board frame, with an embedded GPS and a remote-control receiver. The maneuverable wings have actual feathers from pigeons attached. Previous prototypes had carbon and glass fiber but were much heavier, something now solved with the new wing design.

The PigeonBot’s flying capabilities are enabled by a propeller, a fuselage, and a tail. It has motors, a pair per each wing, that can adjust each of the artificial wings and the feathers at two different joints. The researchers can use a remote to move the wing and lead to the robot to turn and bank, mimicking a real pigeon.

“We determined that birds can steer using their fingers,” Letnink said. Both birds’ wings and human arms share basic structural similarities, he and his team argued. For example, wings have humerus, radius and ulna bones and at each wingtip, birds have finger-like anatomy that can move 30 degrees.

Developing the PigeonBot had its challenges and lessons learned for the researchers. One discovery was that the robot works best when all the feathers come from the same bird. Also, incorporating them into the machine required maintenance, specifically smoothing the feathers by hand.

There are parallels between the PigeonBot and actual planes. That’s why Letnik believes that airplanes of the future will make use of morphing wings by incorporating lessons from pigeons and other birds. “You won’t see a feathers airplane but you’ll find mart materials in them,” he argued.

Catfish hunt pigeons in France

Researchers have for the first time observed catfish lying in shallow waters and hunting pigeons – a weird and unexpected behaviour most likely caused by the lack of food.

They released a set of rather gruesome images, highlighting how the catfish adopt a similar strategy to that used by killer whales hunting seals on ice floes. The catfish located in the River Tarn, Southern France, use their whiskers to sense vibrations in the water caused by the pigeons, thus detecting their presence. They wait in the shallow waters, and then… it’s all bad news for the unsuspecting pigeon.

Pigeons go to the shore to drink water and wash, and recently, fishermen started reporting this catfish hunting technique, alerting local biologists. Julien Cucherousset, from the University of Tolouse, was the first to observe and describe it in a paper published in PLoS ONE.

He believes the catfish do this due to a shortage in their usual diet, which consists of crayfish and smaller fish. The team collected samples from the catfish and analyzed the nitrogen and carbon content in order to determine the amount of pigeon that made up the catfish diet; they concluded certain fish develop a taste for pigeons, preferring it more than the usual prey, eating less fish as they eat more pigeons.

A carrier pigeon, with a cylinder attached.

WWII code found on pigeon still can’t be cracked to this day

A carrier pigeon, with a cylinder attached.

A carrier pigeon, with a cylinder attached.

In 1982, a local resident of Bletchingley, about 20 miles south of London, found the remains of a pigeon while cleaning his home’s chimney. Among the remains, the man found a red cylinder that contained a single sheet of paper marked with 27 codes, each comprised of 4 to 5 characters, delivered through the famous British Pigeon Service most likely sent from Normandy during D-Day or aftermath. What’s interesting though, is that even after thirty years and massive technological advancements, the code can not be read.

The only parts of the message that could have been deciphered so far are the note’s sender, “Sjt. W Swot,” and its code-named recipient, “xo2″ — believed to be British Bomber Command. As many as 250,000 pigeons were trained by the RAF during World World II, which were organized under a specialized unit called the National Pigeon Service. The birds showed their value on numerous occasions, especially when radio communications were down or ultra covert-operation details needed to be conveyed. A reported  32 pigeons were awarded the Dickin Medal, Britain’s highest possible decoration for valor given to animals, during the war.

The reason why the code can’t be cracked as of yet is because it’s been made using a one-time pad — a method of encryption that is difficult to crack without knowing the key.

“The advantage of this system is that, if used correctly, it is unbreakable as long as the key is kept secret. The disadvantage is that both the sending and receiving parties need to have access to the same key, which usually means producing and sharing a large keypad in advance,” Government Communications Headquarters officials said.

“This means that without access to the relevant codebooks and details of any additional encryption used, it will remain impossible to decrypt the message,” they said.

pigeon code

The pigeon in question was found in a home just five miles away from Bletchley Park, where British WWII code-breakers were stationed. The bird must have felt tired and stopped by the chimney to get warm, noxious fumes may have caused it to collapse and eventually meet its end. Most likely, the message will remain unreadable until a member of the operation, if still alive or able, might offer information towards its deciphering.

”We didn’t really hold out any hopes we would be able to read the message,” said Tony, a GCHQ historian who asked to be identified by first name only, to the BBC. “Unless you get rather more idea than we have of who actually sent this message and who it was sent to we are not going to find out what the underlying code being used was.”



Fancy a cup of pigeon milk?

Common sense might tell you that only mammals are capable of lactating, it’s a little know fact, however, that some species of birds are also capable of making milk for their young. The common pigeon produces milk in its crop, located near the esophagus, to feed its young. Scientists have long been wondering how the lactating process takes place for pigeons, but now Deakin University and CSIRO researchers found the gene expression involved. A few years from now we might be all drinking it.

If you find the prospect of such a thing ever happening, consider that its a highly nurturing substance – rich in minerals, protein, fat and antibodies. Since its mainly a bird accustomed and adaptable to all kinds of hazardous environments, pigeon milk is packed full of antioxidants and immune-system-boosting proteins. The pigeon’s e milk is actually a secretion that the parents regurgitate into the young bird’s mouths, helping them grow from their frail infancy. Flamingos and male Emperor penguins, oddly enough, produce it as well.

Deakin University and CSIRO research fellow Tamsyn Crowley said while the function was the same as mammalian milk, the mechanism was completely different.

”We identified a number of immune genes and also found the mechanism by which this process is happening,” she said. ”It’s not like a gland in a mammal that produces the milk. It’s actually part of the crop that falls off and then that is fed to the young.”

The pigeon’s crop, responsible for secreting the milk, is actually part of its digestion chain and is responsible for storing food. The crop however changes immediately prior to lactation in response to hormones and reverts back after lactation, exactly like in any other mammal. The birds begin ”lactating” two-days before the eggs hatch and feed their young for the first 10 days. In the first three days, squabs double their weight daily.
To understand the lactating mechanism in birds, scientists had to sequence the pigeon’s genome, which by their account more or less like flying blind. They did it eventually, of course, after they compared the gene expression of pigeons that do and do not lactate, and eventually compared them to the chicken’s DNA (enough weird science for today; you can’t milk a chicken, don’t worry).They found that the lactating pigeons had over-expression of genes involved with immune response and antioxidant production, as well as genes involved in the production of triglycerides.

‘If you can find proteins that are protecting against disease in pigeons, there’s nothing to say that that can’t be applied in other birds, such as chickens,” she said. ”And that could be a good thing for an industry that is already looking at ways to minimise antibiotics.”

As long as they don’t make lactating chickens, I’m all cool with it. The paper was published in the journal BMC Genomics.