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12 Scientifically Cute Facts About Puppies

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Puppies are hard-wired to appeal to us, with their adorable squishy faces, little paws, and wet noses. But there is more to young dogs than downy fur and floppy ears. Here are 12 scientific facts about them to coo over:

1. THEY LIKE BABY TALK.

A January 2017 study found that puppies respond when humans speak in sing-song tones, but adult dogs couldn’t care less. Researchers from the University of Lyon at Saint-Etienne found that people speak more slowly and at a much higher pitch when talking to puppies (or pictures of them, at least) than when talking to humans or adult dogs. When the researchers played recordings of participants’ puppy talk to dogs, they found that the puppies showed greater responses to the cooing than to recordings of humans using their regular (human-directed) voices. Adult dogs, on the other hand, did not. It’s hard to say why that is, but it could be that puppies are wired to respond to high-pitched sounds, but they eventually grow out of it.

2. THEY CAN HELP YOU FOCUS.

Looking at cute pictures of puppies at work is more productive than you’d think. In a 2012 study, Japanese researchers found that viewing pictures of puppies made people better at tasks that required close attention. Viewing pictures of older dogs, however, was not as effective. People were more effective and more careful in accomplishing the tasks before them if they were flooded by the positive emotions of seeing an amazingly adorable baby animal. The researchers suggest that maybe people should look at cute things before driving or at work to help them focus.

3. THEY REALLY DO LIKE YOU.

In a Hungarian study published in 2005, researchers found that pet puppies show specific attachments to the humans that care for them. While even wolves that had been hand-raised from birth by humans didn’t show any preference for the people that raised them—they reacted the same way to strangers as to the caregivers they had spent their entire lives with—domestic puppies as young as 4 months old showed a significant preference to their owners. They followed and greeted their owners more than they did strange humans, and when their owner left, they tended to stand by the door waiting for them to return. This difference was observed in both puppies that had been hand-raised with extensive socialization and puppies that had been reared in a litter by their mothers, indicating that as a species, dogs have evolved to bond with their human owners.

4. THEIR SENSES DON'T DEVELOP UNTIL A FEW WEEKS AFTER BIRTH.

When they’re first born, puppies only respond to warmth, touch, and smell. Their eyes remain closed, and they can’t hear. Puppies don’t fully develop the ability to hear until they are 4 weeks old, and it is not until 6 weeks of age, on average, that they develop full vision. Once their senses develop, they begin exploring the world in earnest, beginning a critical period of socialization.

5. IT'S IMPORTANT TO FAMILIARIZE THEM WITH PEOPLE EARLY.

Studies [PDF] have shown that puppies are most socially malleable during their second month of life. During that time, their sensory systems are developed enough to let them explore, but they’re not yet fearful of new experiences. As one 1961 study on puppy litters isolated from humans found, puppies that aren’t played with showed "increasing tendency to withdraw from human beings after 5 weeks of age and unless socialization occurred before 14 weeks of age, withdrawal reactions from humans became so intense that normal relationships could not thereafter be established."

6. THEIR PHYSICAL AND EMOTIONAL DEVELOPMENT VARIES BY BREED.

Puppies don’t all develop on the same timeline. A 2015 study of almost 100 purebred dogs found that different breeds of dogs develop a sense of fear at different times in puppyhood. The researchers put puppies from 4 weeks old to 10 weeks old through several tests designed to provoke a fear response, like making them listen to a loud bang or explore a seesaw. They found that Cavalier King Charles spaniels didn’t show fear-related behavior (like crouching down) until later than German shepherds or Yorkshire terriers. While German shepherds typically began showing a fear response around 35 days old, the spaniels didn’t start avoiding scary stimuli until 55 days old.

7. THEY LEARN TO UNDERSTAND HUMAN GESTURES AS THEY AGE.

Dogs can understand human social cues like pointing, but it’s something that they learn over time. In 2007, researchers tested 6-, 8-, 16-, and 24-week-old puppies [PDF] on their ability to decode a human’s finger point. Though these researchers reported that dogs of all ages could understand the cue and use it to find food under a cup, subsequent analysis by another research group showed that actually, those skills improved over time [PDF]. The older the dogs were, the better they were able to understand the pointing and suss out the correct cup. In itself, the act of testing seemed to help them learn, too. The youngest puppies showed improvement between the first half of their trials and the second half, the 2008 follow-up analysis found.

8. THEY DON'T CRY AS MUCH AS ADULT DOGS.

Dogs aren’t born with very moist eyes. One 2012 study found that 4-week-old puppies do produce basal tears, but in much smaller quantities than adult dogs. Their eyes get wetter every day, finally reaching adult levels of tears at about 10 weeks old. By contrast, full-term human babies have eyes which are just as wet as those of adults, unless they’re born premature, in which case they have lower secretions of tears until a few weeks later. (These are just the tears that keep eyes moist, not the psychological kind.)

9. THEIR LITTER SIZE DEPENDS A LOT ON BREED.

How many puppies a dog has varies by breed. While a 2011 review of birth data from 224 dog breeds found that the average purebred dog litter consisted of five or so puppies (5.4, to be exact), older and smaller dogs tend to have fewer puppies. Rhodesian Ridgebacks gave birth to the most puppies (an average of 8.9 puppies per litter), while toy Poodles and Pomeranians gave birth to an average of 2.4 puppies at a time.

10. THEY'RE NOT ALWAYS PLANNED.

In one of the first benchmark studies on pet population trends in the U.S., researchers found that 43 percent of puppy litters in 1996 were unplanned—about 2.6 million compared to 3.38 million planned litters. That’s a lot less than the whopping 83 percent of kitten litters that were unplanned.

11. THEY CAN BE IDENTICAL TWINS.

In 2016, a veterinarian encountered what is thought to be the first verified instance of identical twin puppies. When South African vet Kurt de Cramer performed a C-section on a pregnant Irish wolfhound, he discovered that two male puppies shared the same placenta. Later, he had their DNA tested and confirmed that they were, in fact, identical twins.

12. THEIR BEHAVIORAL TRAITS AREN'T SET YET AT 8 WEEKS OLD.

A long-term study of 1235 German shepherd puppies bred at the Swedish Dog Training Center in the late 1970s and early 1980s found that at 8 weeks old, a dog’s personality is not yet developed enough to analyze. The researchers wanted to know if suitability tests for guide dogs and other working dogs could be accurately performed on puppies as young as 8 weeks old. They found that at that point, puppy behavior is still changing rapidly, and test results from that young wouldn’t reveal much about the future behavior of the dog as an adult. In other words, it’s O.K. if your puppy is an idiot (or rambunctious, or whiny)—he’ll grow out of it, hopefully.

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15 Incredible Facts About Pigeons
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Though they're often described as "rats with wings" (a phrase popularized by the movie Stardust Memories), pigeons are actually pretty cool. From homing instincts to misleading rump feathers, here are 15 things you might not know about these avian adventurers.

1. THEY MIGHT BE THE FIRST DOMESTICATED BIRD.

The common city pigeon (Columba livia), also known as the rock pigeon, might be the first bird humankind ever domesticated. You can see them in art dating back as far as 4500 BCE in modern Iraq, and they've been a valuable source of food for thousands of years.

2. THEY WON OVER CHARLES DARWIN—AND NIKOLA TESLA.

Pigeon-breeding was a common hobby in Victorian England for everyone from well-off businessmen to average Joes, leading to some fantastically weird birds. Few hobbyists had more enthusiasm for the breeding process than Charles Darwin, who owned a diverse flock, joined London pigeon clubs, and hobnobbed with famous breeders. Darwin's passion for the birds influenced his 1868 book The Variation of Animals and Plants Under Domestication, which has not one but two chapters about pigeons (dogs and cats share a single chapter).

Nikola Tesla was another great mind who enjoyed pigeons. He used to care for injured wild pigeons in his New York City hotel room. Hands down, Tesla's favorite was a white female—about whom he once said, "I loved that pigeon, I loved her as a man loves a woman and she loved me. When she was ill, I knew and understood; she came to my room and I stayed beside her for days. I nursed her back to health. That pigeon was the joy of my life. If she needed me, nothing else mattered. As long as I had her, there was a purpose in my life." Reportedly, he was inconsolable after she died.

3. THEY UNDERSTAND SPACE AND TIME.

In a 2017 Current Biology study, researchers showed captive pigeons a series of digital lines on a computer screen for either two or eight seconds. Some lines were short, measuring about 2.3 inches across; others were four times longer. The pigeons were trained to evaluate either the length of the line or how long it was displayed. They found that the more time a line was displayed, the longer in length the pigeon judged it to be. The reverse was true too: If the pigeons encountered a longer line, they thought it existed in time for a greater duration. Pigeons, the scientists concluded, understand the concepts of both time and space; the researchers noted "similar results have been found with humans and other primates."

It's thought that humans process those concepts with a brain region called the parietal cortex; pigeon brains lack that cortex, so they must have a different way of judging space and time.

4. THEY CAN FIND THEIR WAY BACK TO THE NEST FROM 1300 MILES AWAY.

A pigeon flying in front of trees.
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The birds can do this even if they've been transported in isolation—with no visual, olfactory, or magnetic clues—while scientists rotate their cages so they don't know what direction they're traveling in. How they do this is a mystery, but people have been exploiting the pigeon's navigational skills since at least 3000 BCE, when ancient peoples would set caged pigeons free and follow them to nearby land.

Their navigational skills also make pigeons great long-distance messengers. Sports fans in ancient Greece are said to have used trained pigeons to carry the results of the Ancient Olympics. Further east, Genghis Khan stayed in touch with his allies and enemies alike through a pigeon-based postal network.

5. THEY SAVED THOUSANDS OF HUMAN LIVES DURING WORLD WARS I AND II.

Pigeons' homing talents continued to shape history during the 20th century. In both World Wars, rival nations had huge flocks of pigeon messengers. (America alone had 200,000 at its disposal in WWII.) By delivering critical updates, the avians saved thousands of human lives. One racing bird named Cher Ami completed a mission that led to the rescue of 194 stranded U.S. soldiers on October 4, 1918.

6. TWO PIGEONS ALMOST DISTRACTED FROM THE DISCOVERY OF EVIDENCE OF THE BIG BANG.

In 1964, scientists in Holmdel, New Jersey, heard hissing noises from their antenna that would later prove to be signals from the Big Bang. But when they first heard the sound, they thought it might be, among other things, the poop of two pigeons that were living in the antenna. "We took the pigeons, put them in a box, and mailed them as far away as we could in the company mail to a guy who fancied pigeons," one of the scientists later recalled. "He looked at them and said these are junk pigeons and let them go and before long they were right back." But the scientists were able to clean out the antenna and determine that they had not been the cause of the noise. The trap used to catch the birds (before they had to later be, uh, permanently removed) is on view at the Smithsonian Air & Space Museum.

7. YOU CAN TRAIN THEM TO BE ART SNOBS …

Japanese psychologist Shigeru Watanabe and two colleagues earned an Ig Nobel Prize in 1995 for training pigeons, in a lab setting, to recognize the paintings of Claude Monet and Pablo Picasso and to distinguish between the painters. The pigeons were even able to use their knowledge of impressionism and cubism to identify paintings of other artists in those movements. Later, Watanabe taught other pigeons to distinguish watercolor images from pastels. And in a 2009 experiment, captive pigeons he'd borrowed were shown almost two dozen paintings made by students at a Tokyo elementary school, and were taught which ones were considered "good" and which ones were considered "bad." He then presented them with 10 new paintings and the avian critics managed to correctly guess which ones had earned bad grades from the school's teacher and a panel of adults. Watanabe's findings indicate that wild pigeons naturally categorize things on the basis of color, texture, and general appearance.

8. … AND TO DISTINGUISH WRITTEN WORDS.

In a 2016 study, scientists showed that pigeons can differentiate between strings of letters and actual words. Four of the birds built up a vocabulary of between 26 and 58 written English words, and though the birds couldn't actually read them, they could identify visual patterns and therefore tell them apart. The birds could even identify words they hadn't seen before.

9. FLUFFY PIGEON FEET MIGHT ACTUALLY BE PARTIAL WINGS.

A white pigeon with curly feathers and fluffy feet.
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A few pigeon breeds have fuzzy legs—which hobbyists call "muffs"—rather than scaly ones. According to a 2016 study, the DNA of these fluffy-footed pigeons leads their hind legs to take on some forelimb characteristics, making muffed pigeon legs look distinctly wing-like; they're also big-boned. Not only do they have feathers, but the hindlimbs are somewhat big-boned, too. According to biologist Mike Shapiro, who led the study, "pigeons' fancy feathered feet are partially wings."

10. SOME PIGEONS DISTRACT FALCONS WITH WHITE RUMP FEATHERS.

In a life-or-death situation, a pigeon's survival could depend upon its color pattern: Research has shown that wild falcons rarely go after pigeons that have a white patch of feathers just above the tail, and when the predators do target these birds, the attacks are rarely successful.

To figure out why this is, Ph.D. student Alberto Palleroni and a team tagged 5235 pigeons in the vicinity of Davis, California. Then, they monitored 1485 falcon-on-pigeon attacks over a seven-year span. The researchers found that although white-rumped pigeons comprised 20 to 25 percent of the area's pigeon population, they represented less than 2 percent of all the observed pigeons that were killed by falcons; the vast majority of the victims had blue rumps. Palleroni and his team rounded up 756 white- and blue-rumped pigeons and swapped their rump feathers by clipping and pasting white feathers on blue rumps, and vice versa. The falcons had a much easier time spotting and catching the newly blue-rumped pigeons, while the pigeons that received the white feathers saw predation rates plummet.

Close observation revealed that the white patches distract birds of prey. In the wild, falcons dive-bomb other winged animals from above at high speeds. Some pigeons respond by rolling away in midair, and on a spiraling bird, white rump feathers can be eye-catching, which means that a patch of them may divert a hungry raptor's focus long enough to make the carnivore miscalculate and zip right past its intended victim.

11. DODOS WERE RELATED TO TODAY'S PIGEONS.

Two blue and green Nicobar pigeons.
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Though most of this list focuses on the rock pigeon, there are 308 living species of pigeons and doves. Together, they make up an order of birds known as the columbiformes. The extinct dodo belonged to this group as well.

Flightless and (somewhat) docile, dodos once inhabited Mauritius, an island near Madagascar. The species had no natural predators, but when human sailors arrived with rats, dogs, cats, and pigs, it began to die out, and before the 17th century came to a close, the dodo had vanished altogether. DNA testing has confirmed that pigeons are closely related to the dodo, and the vibrant Nicobar pigeon (above) is its nearest genetic relative. A multi-colored bird with iridescent feathers, this near-threatened creature is found on small islands in the South Pacific and off Asia. Unlike the dodo, it can fly.

12. AT ONE POINT, MORE THAN ONE-QUARTER OF ALL THE BIRDS LIVING IN THE U.S. MAY HAVE BEEN PASSENGER PIGEONS.

Wild/feral rock pigeons reside in all 50 states, which makes it easy to forget that they're invasive birds. Originally native to Eurasia and northern Africa, the species was (most likely) introduced to North America by French settlers in 1606. At the time, a different kind of columbiform—this one indigenous—was already thriving there: the passenger pigeon (Ectopistes migratorius). As many as 5 billion of them were living in America when England, Spain, and France first started colonizing, and they may have once represented anywhere from 25 to 40 percent of the total U.S. bird population. But by the early 20th century, they had become a rare sight, thanks to overhunting, habitat loss, and a possible genetic diversity issue. The last known passenger pigeon—a captive female named Martha—died on September 1, 1914.

13. THEY'RE REALLY GOOD AT MULTITASKING.

According to one study, they're more efficient multitaskers than people are. Scientists at Ruhr-Universitat Bochum put together a test group of 15 humans and 12 pigeons and trained all of them to complete two simple jobs (like pressing a keyboard once a light bulb came on). They were also put in situations wherein they'd need to stop working on one job and switch over to another. In some trials, the participants had to make the change immediately. During these test runs, humans and pigeons switched between jobs at the same speed.

But in other trials, the test subjects were allowed to complete one assignment and then had to wait 300 milliseconds before moving on to the next job. Interestingly, in these runs, the pigeons were quicker to get started on that second task after the period ended. In the avian brain, nerve cells are more densely packed, which might enable our feathered friends to process information faster than we can under the right circumstances.

14. PIGEONS PRODUCE FAKE "MILK."

Only mammals produce genuine milk, but pigeons and doves (along with some other species of birds) feed their young with something similar—a whitish liquid filled with nutrients, fats, antioxidants, and healthy proteins called "crop milk." Both male and female pigeons create the milk in the crop, a section of the esophagus designed to store food temporarily. As is the case with mammal milk, the creation of crop milk is regulated by the hormone prolactin. Newly-hatched pigeons drink crop milk until they're weaned off it after four weeks or so. (And if you've ever asked yourself, "Where are all the baby pigeons?" we have the answer for you right here.)

15. ONE STUDY SUGGESTS THAT, GIVEN THE RIGHT CONDITIONS, THEY'RE AS GOOD AT IDENTIFYING CANCER AS DOCTORS.

We've already established that pigeons are excellent at differentiating between artists and words, but a 2015 study revealed they can also distinguish between malignant and benign growths in the right conditions. Researchers at University of California Davis Medical Center put 16 pigeons in a room with magnified biopsies of potential breast cancers. If the pigeons correctly identified them as either benign or malignant, they got a treat, According to Scientific American.

"Once trained, the pigeons' average diagnostic accuracy reached an impressive 85 percent. But when a "flock sourcing" approach was taken, in which the most common answer among all subjects was used, group accuracy climbed to a staggering 99 percent, or what would be expected from a pathologist. The pigeons were also able to apply their knowledge to novel images, showing the findings weren't simply a result of rote memorization."

Mammograms proved to be more of a challenge, however; the birds could memorize signs of cancer in the images they were trained on but could not identify the signs in new images.

No matter how impressive their results, "I don't anticipate that pigeons, no matter how good they become at pathology or radiology, will be playing a role in actual patient care—certainly for the foreseeable future," study co-author Richard M. Levenson told Scientific American. "There are just too many regulatory barriers—at least in the West."

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'Angry Badger' Terrorizes Scottish Castle, Forcing Closures 
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Portions of the 16th-century Craignethan Castle in Scotland were shut down last week after a less-than-friendly badger holed up there and refused to leave. Historic Environment Scotland, which manages the site in South Lanarkshire, sent out a tweet last Friday notifying visitors that the property's cellar tunnel would remain closed over the weekend “due to the presence of a very angry badger.” Staff tried to coax it out with cat food and honey, but the badger did what it wanted, and they were unable to move the mammal.

A spokesman for HES told the BBC, "The castle is surrounded by woodland and we believe the badger may have become lost. Staff first spotted some dug-out earth on Wednesday evening, and later spotted the badger on closer inspection."

On Saturday, staff used a GoPro camera to check out the tunnel from a safe distance and learned that the badger had left voluntarily, but not before making a mess. The critter dug through both soil and stonework, according to The Scotsman. The castle, an artillery fortification erected around 1530, is already partly in ruins.

Craignethan Castle in Scotland
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Badgers are not typically dangerous, but they can become aggressive if they feel cornered or threatened. They can be seen year-round in Scotland, especially during spring and summer. Earthworms, bird eggs, small mammals, fruit, and roots are among their favorite meals, and they can even be “tempted into your garden by leaving peanuts out—a tasty snack for our striped friends,” the Scottish Wildlife Trust says.

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