Although pigeons have brains that are no bigger than the tip of an index finger, several in a recent study were able to distinguish digitized microscope slides and mammograms of normal versus cancerous breast tissue.
Their rate of accuracy, about 90 percent in one experiment and 99 percent in another, is equivalent to that of humans with medical training. Don't expect pigeons at your next doctor's appointment, however.
The findings - published in the journal PLOS ONE - will be used to improve human performance at such tasks in future by correcting unclear aspects of the medical images, such as representations of tissue density. Evaluating tissue density has proven to be challenging not only for pigeons, but also for skilled human radiologists.
Pigeons Aren't 'Rats with Wings,' They're Superbirds
"With some training and selective food reinforcement, pigeons do just as well as humans in categorizing digitized slides and mammograms of benign and malignant human breast tissue," lead author Richard Levenson, professor of pathology and laboratory medicine at UC Davis Health System, said in a press release.
"The pigeons were able to generalize what they had learned, so that when we showed them a completely new set of normal and cancerous digitized slides, they correctly identified them," he continued. "Their accuracy, like that of humans, was modestly affected by the presence or absence of color in the images, as well as by degrees of image compression."
"The pigeons," he added, "also learned to correctly identify cancer-relevant micro-calcifications on mammograms, but they had a tougher time classifying suspicious masses on mammograms - a task that is extremely difficult, even for skilled human observers."
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The training environment for the pigeons, shown in the below video, included a food pellet dispenser, a touch-sensitive screen that projected the medical image, as well as blue and yellow choice buttons on either side of the image. Pecks to those buttons and to the screen were automatically recorded.
Prior research, along with this study, suggest that intelligence is not necessarily connected to brain size. In fact, the neural pathways that pigeons use to discriminate one photo from another are very similar to those in the human brain.
As a result, pigeons can assess and categorize a wide range of objects and images.
"Research over the past 50 years has shown that pigeons can distinguish identities and emotional expressions on human faces, letters of the alphabet, misshapen pharmaceutical capsules, and even paintings by Monet versus Picasso," said co-author Edward Wasserman of The University of Iowa. "Their visual memory is equally impressive, with a proven recall of more than 1,800 images."
The scientists indicate that pigeons, to some extent, may then serve as human surrogates for certain limited, yet important, undertakings like the one highlighted in the study.
As Levenson said, "This is a difficult, time-consuming, and expensive process that requires the recruitment of clinicians as subjects for these relatively mundane tasks... (Pigeons) can assist researchers and engineers as they (the scientists) continue to innovate."
Pigeon studying a photo to determine whether or not it shows cancerous breast cells.
In honor of New York Fashion Week, the
(WCS) has named its top 10 list of wildlife fashionistas. The list celebrates finned, feathered, and furry fashion icons of the animal kingdom. "If you look at the natural world, it is clear that humans are not the only ones that are conscious about their physical appearance," WCS spokesperson Stephen Sautner told Discovery News. "Wildlife are concerned about how they look, too," he added, "whether it is maintaining their plumage to attract a mate, or using their natural camouflage to hunt or hide." The Victoria crowned pigeon, shown here, has an unforgettable hollow drum-sounding
, which it makes while bowing and showing off its tail feathers.
These two king penguins take on a royal air as they strut proudly down a beach. As Sautner said, "One thing about the world's 17 species of penguins: no matter what, every occasion calls for a tux."
The rainbow bush locust,
Phymateus saxosus
, is a member of the "gaudy grasshopper" family. Its bright coloration signifies that it is toxic due, in part, to the grasshopper's feasting on plants that are highly poisonous to others. When disturbed, they can secrete a noxious fluid meant to turn off anyone who would dare to take a taste of them.
Bright coloration in nature often signals poison. That is true for this strawberry poison dart frog, and other poison dart frogs. This one-inch-long frog is also a world-class wrestler, at least among amphibians. For up to 20 minutes, males competing over mates and territories may stand on their hind legs and try to push their opponent to the ground. Once the loser is pinned, he must slink away, leaving the victor to his earned turf.
"The chapeau of this jolly jelly is straight from Lady Gaga's wardrobe," Sautner said. This creature is basically all "hat" too, since jellyfish do not have a head, brain, bones, cartilage or true eyes. What the flower hat jellyfish does have are multicolored tentacles protruding from its translucent, striped bell. Curious people are advised to keep their distance, as the sting of this jellyfish is painful and can leave a bright red rash.
The okapi, a mammal related to giraffes, looks as if it is wearing fashionable leggings 24/7. Sautner explained, "The Okapi's distinct striped legs serve as excellent camouflage in the sun dappled central African jungles where they call home."
The mandrill is a primate that is closely related to baboons. It is found in southern Cameroon, Gabon, Equatorial Guinea and the Congo. "The world's most colorful mammal, the male mandrill (left) dazzles in red and blue," Sautner said. "It uses these colors to attract mates and to show dominance."
About the palawan peacock-pheasant, Sautner said, "The male's spectacular plumage is always runway ready." He explained that the males use their colorful feathers to attract mates.
Cuttlefish are always ready to blend in, or to stand out. They can change their body color in an instant for camouflage and to otherwise suit their needs. Their ability to disappear into their environments functions, according to Sautner, like a "virtual cloaking device that allows them to hide from predators or hunt for prey."
Coral snakes have the second most potent venom of any snake. (Many wildlife experts believe that the black mamba holds the infamous number one spot.) Most coral snakes tend to avoid humans, however, and are usually non-confrontational. All coral snakes sport eye-catching patterns and colors. Sautner said that the coral snake is "a killer on the runway; never has danger been so pretty."