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Illustrator unknown via Wikimedia Commons // Public Domain
Illustrator unknown via Wikimedia Commons // Public Domain

These Fish Can Recognize Human Faces

Illustrator unknown via Wikimedia Commons // Public Domain
Illustrator unknown via Wikimedia Commons // Public Domain

We really need to stop underestimating our fellow creatures. A new study adds a talented tropical fish to the swelling ranks of non-human animals that can tell humans apart. The research was published in the journal Scientific Reports. 

Facial recognition is a vital but complex task—so complex that humans have an entire region in our brains dedicated to it. And because it’s such a sophisticated process, scientists used to assume that we were the only animals that could do it. Then that circle widened a little bit to include other primates. But that circle just keeps growing, and currently includes octopuses, bees, and at least four types of birds. This is, admittedly, kind of strange; with the possible exception of birds, none of these animals have any natural need to tell people apart. 

Nor do fish. And like the cognitive abilities of birds, bees, and cephalopods, fishes’ mental skills have been more or less written off until quite recently. With this fact in mind, a team of researchers from the UK and Australia decided to find out if fish were up to the task. 

One species, the archerfish (Toxotes chatareus), seemed especially well-suited for the experiment. Archerfish are amazing creatures with a super-cool hunting strategy: They wait near the water’s surface for an insect to land on a nearby leaf, then shoot a jet of water at the bug, knocking it into the water. 

Illustration: Pearson Scott Foresman via Wikimedia Commons // Public Domain

Their aim is superb, and their vision acute, which suggests fairly sophisticated mental function. It also makes them great experimental subjects, since they can be trained to choose an object or image by spitting at it. 

The new study consisted of training and two experiments. First, researchers set up a screen above a tank holding a single fish. To see if the fish could tell the difference between two faces, the scientists displayed two faces on the screen, then attempted to train the fish to spit water at only one of them whenever it appeared. The training worked, and quickly, too; within just a few sessions, all the fish had learned to spit at the right face.

Image Credit: Newport et al. 2016.Nature Communications

Then the researchers brought back the same fish and exposed them to lots and lots of faces—44, to be precise. The goal was to see if the fish could still pick out the face they learned in the first round of training. To make it even harder, the researchers then cut all the face images into oval shapes and displayed them in grayscale so the fish couldn’t rely on more obvious cues like face shape or color. 

But the fish didn’t need color or shape. As in their hunting, the archerfish were incredibly accurate when it came to spotting faces. In the first round of 44 faces, the fish subjects averaged 81 percent accuracy. Once the obvious cues were removed they did even better, selecting the right face 86 percent of the time.   

“Fish have a simpler brain than humans and entirely lack the section of the brain that humans use for recognizing faces,” said lead author and Oxford University zoologist Cait Newport in a press statement. “The fact that archerfish can learn this task suggests that complicated brains are not necessarily needed to recognize human faces.”

 

 

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Animals
Pigeons Are Secretly Brilliant Birds That Understand Space and Time, Study Finds
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Of all the birds in the world, the pigeon draws the most ire. Despite their reputation as brainless “rats with wings,” though, they’re actually pretty brilliant (and beautiful) animals. A new study adds more evidence that the family of birds known as pigeons are some of the smartest birds around, as Quartz alerts us.

In addition to being able to distinguish English vocabulary from nonsense words, spot cancer, and tell a Monet from a Picasso, pigeons can understand abstract concepts like space and time, according to the new study published in Current Biology. Their brains just do it in a slightly different way than humans’ do.

Researchers at the University of Iowa set up an experiment where they showed pigeons a computer screen featuring a static horizontal line. The birds were supposed to evaluate the length of the line (either 6 centimeters or 24 centimeters) or the amount of time they saw it (either 2 or 8 seconds). The birds perceived "the longer lines to have longer duration, and lines longer in duration to also be longer in length," according to a press release. This suggests that the concepts are processed in the same region of the brain—as they are in the brains of humans and other primates.

But that abstract thinking doesn’t occur in the same way in bird brains as it does in ours. In humans, perceiving space and time is linked to a region of the brain called the parietal cortex, which the pigeon brains lack entirely. So their brains have to have some other way of processing the concepts.

The study didn’t determine how, exactly, pigeons achieve this cognitive feat, but it’s clear that some other aspect of the central nervous system must be controlling it. That also opens up the possibility that other non-mammal animals can perceive space and time, too, expanding how we think of other animals’ cognitive capabilities.

[h/t Quartz]

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The Queen's Racing Pigeons Are in Danger, Due to an Increase in Peregrine Falcons
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Queen Elizabeth is famous for her love of corgis and horses, but her pet pigeons don't get as much press. The monarch owns nearly 200 racing pigeons, which she houses in a luxury loft at her country estate, Sandringham House, in Norfolk, England. But thanks to a recent boom in the region’s peregrine falcon population, the Queen’s swift birds may no longer be able to safely soar around the countryside, according to The Telegraph.

Once endangered, recent conservation efforts have boosted the peregrine falcon’s numbers. In certain parts of England, like Norfolk and the city of Salisbury in Wiltshire, the creatures can even find shelter inside boxes installed at local churches and cathedrals, which are designed to protect potential eggs.

There’s just one problem: Peregrine falcons are birds of prey, and local pigeon racers claim these nesting nooks are located along racing routes. Due to this unfortunate coincidence, some pigeons are failing to return to their owners.

Pigeon racing enthusiasts are upset, but Richard Salt of Salisbury Cathedral says it's simply a case of nature taking its course. "It's all just part of the natural process,” Salt told The Telegraph. "The peregrines came here on their own account—we didn't put a sign out saying 'room for peregrines to let.' Obviously we feel quite sorry for the pigeons, but the peregrines would be there anyway."

In the meantime, the Queen might want to keep a close eye on her birds (or hire someone who will), or consider taking advantage of Sandringham House's vast open spaces for a little indoor fly-time.

[h/t The Telegraph]

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