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10 Colorful Facts About Chameleons

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You probably know that these lizards can change their skin color, but they’ve got plenty of other special tricks as well. In fact, they might be the world’s most talented reptiles. Chameleons can shoot out their tongues at alarming speeds, use their tails as extra limbs, and even see in two different directions at once. Impressive, no?

1. THEIR FEET WORK LIKE SALAD TONGS.

Most lizards have fairly unremarkable feet. In the majority of species, they're comprised of four to five toes that can move independently of each other—just as ours do. But evolution has taken chameleon limbs in a very different direction. A chameleon’s foot consists of two fleshy pads that oppose each other. One pad contains three digits that are fused together while the other has two fused digits.

Up in the tree canopies where they live, these feet come in handy. Like a set of pincers, the opposing pads on each foot firmly clamp down onto vines and branches. Also, whereas most lizards have sprawling limbs, chameleons usually hold their legs almost directly underneath their bodies. This gives them an athletic gait for a modern reptile—walking this way keeps the center of gravity directly above the feet, which helps the animals stay balanced.

2. ALMOST HALF OF ALL KNOWN SPECIES LIVE IN MADAGASCAR.

Currently, there are around 200 different chameleon species, 44 percent of which can be found on Madagascar—leading some experts to wonder if the whole chameleon family originally evolved there (although a modern analysis deemed mainland Africa a more likely origin point). Elsewhere in the world, some members of this incredible group occur naturally in India, Asia minor, southern Europe, and mainland Africa.

3. CHAMELEONS VARY WILDLY IN TERMS OF SIZE.

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In 2012, researchers discovered a new species of chameleon that—as of this writing—is the smallest on record. Known as Brookesia micra, the diminutive animal dwells on Nosy Hara, an islet off the coast of Madagascar. The diurnal lizard’s maximum adult length is only an inch, and juveniles can fit on the head of a match. (Sure, it's a cliche, but ... really. They can.) Meanwhile, mainland Madagascar is home to the two largest chameleons on record: the Oustalet’s chameleon and the Parson’s chameleon, each of which can grow up to 27 inches.

4. THEY MAINLY CHANGE COLOR IN ORDER TO COMMUNICATE OR REGULATE BODY TEMPERATURE.

Contrary to popular belief, when a chameleon changes its skin color, the animal usually isn’t trying to camouflage itself by blending into the environment. More often, this remarkable ability is used as a way of controlling its body temperature. By lightening their skin, chameleons can cool themselves down, since lighter colors are better at reflecting the sun’s rays. On the other hand, adopting a dark complexion is a good way to warm up when it gets chilly outside.

Another primary function of color change is communication: Altering skin tone can let potential mates or rivals know what’s on your mind. For example, a female common chameleon (Chamaeleo chamaeleon) displays bright yellow spots when she’s ready to mate. Afterwards, she’ll darken her skin tone and show off blue and yellow spots to inform nearby males to stay away. (Angry hisses also help get the point across.)

Males, too, wear their emotions on their skin. When two bull graceful chameleons (Chamaeleo gracilis) cross paths, their skins become paler and more heavily spotted. Faced with the same situation, a pair of male warty chameleons (Furcifer verrucosus) will turn bright blue and green—but only on the lower half of their bodies.

When such displays aren’t enough, many males won’t shy away from physical confrontation. Amazingly, it looks like variations in skin color might predict the outcome of these squabbles before they happen. In 2013, Russell Ligon and Kevin McGraw of Arizona State University monitored 45 encounters between captive veiled chameleons (Chamaeleo calyptratus—pictured above). Before engaging with each other, males of this species show off the vibrant stripes on their sides. Both lizards intentionally brighten these up as a way to demonstrate their health while also making themselves look bigger. Ligon and McGraw discovered that—in most cases—any resulting fight was won by whichever combatant had brighter and more rapidly-changing stripes.

5. SKIN CRYSTALS ENABLE THEM TO CHANGE COLOR AT WILL.

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Until recently, scientists thought that the reptiles changed color by manipulating the pigments inside their skin cells. But it's much more complicated. In 2015, scientists at the University of Geneva took a close look at the skin of the male panther chameleon (Furcifer pardalis) and discovered two layers of specialized cells lying under the creature’s hide that were loaded with tiny nanocrystals—the key to a chameleon’s color-changing prowess.

The name of the game is reflection. When a male panther chameleon is relaxed, the cells containing its crystals are held closely together. In this position, they reflect blue light, which—when filtered through yellow skin pigments—makes the animal look green. Somehow, chameleons can expand and reduce the distance between those nanocrystals. By spreading them farther apart, the reptiles cause their crystals to reflect yellow or red light. The skin’s apparent color then changes accordingly.

6. UNLIKE MANY LIZARDS, CHAMELEONS CAN’T REGROW THEIR TAILS.

Most chameleons have long, grasping tails that basically function like a fifth limb. In the majority of species, it can support the animal’s entire bodyweight, allowing a chameleon to move between branches more easily. One thing that the appendage cannot do, however, is automatically break off when a predator grabs it, as the tails of anoles, leopard geckos, and many other lizards do—if a chameleon’s tail is severed, it won’t grow a replacement.

7. THEIR EYES CAN SWIVEL AROUND IN TWO DIFFERENT DIRECTIONS SIMULTANEOUSLY.

Each eye has the incredible range of motion of 90 degrees vertically and 180 degrees horizontally. And that’s not all: The peepers can also move in opposite directions—so while one eye is looking upwards and to the left, the other might simultaneously wander downwards and to the right. This allows a chameleon to scan most of the surrounding area for food without even moving its head. If one wandering eye should spy a tasty insect, the other one will move over and fixate on the target as well, giving the lizard some depth perception.

8. SMALLER CHAMELEONS HAVE FASTER TONGUES.

After a chameleon gets both eyes locked onto its prey, a high-speed weapon is deployed: the reptile’s ultra-sticky tongue, which can be 2.5 times as long as its body and can be deployed and reeled back in in less than a second.

Recently, biologist Christopher Anderson used a high-speed camera to record 55 different chameleons—representing 20 species—as they snapped up prey. Anderson noted that the speed and relative force of a chameleon’s tongue seems to be inversely proportional to the creature’s overall size. In other words, it looks like smaller species can fire their tongues more rapidly and more powerfully than their bigger cousins do. The tiniest species that Anderson examined was Rhampholeon spinosus, which fired off its tongue at 8500 feet per second. Meanwhile, the biggest lizard of the bunch—a 2-foot-long Oustalet’s chameleon—had a peak tongue acceleration rate that was 18 percent slower.

9. CHAMELEON SPIT IS UNBELIEVABLY STICKY.

How does a chameleon’s tongue hold onto the insects and small vertebrates it touches? With spit that's 400 times more viscous than that of a human being. This ultra-sticky substance coats the tongue, giving the lizards an edge that helps them pull even heavy victims into their jaws.

10. THEY’VE GOT A DISTINCTIVE “JERKY WALK.”

These lizards are known to sway back and forth—sometimes erratically—while walking. If there’s a method to this madness, scientists have yet to identify it. Many speculate that the weird behavior helps chameleons imitate swaying tree leaves, thus further camouflaging themselves. However, so far, no one’s been able to prove this hypothesis.

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Potato-Based Pet Food Could Be Linked to Heart Disease in Dogs
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If you have a pup at home, you may want to check the ingredients listed on that bag of dog food in your cupboard. The U.S. Food & Drug Administration has warned that potato-based pet foods might be linked to heart disease in dogs, Time reports.

Foods containing lentils, peas, and other legume seeds are also a potential risk, the agency’s Center for Veterinary Medicine announced.

“We are concerned about reports of canine heart disease, known as dilated cardiomyopathy (DCM), in dogs that ate certain pet foods containing peas, lentils, other legumes or potatoes as their main ingredients,” Martine Hartogensis of the veterinary center said in a statement. “These reports are highly unusual as they are occurring in breeds not typically genetically prone to the disease.”

Recent cases of heart disease have been reported in various breeds—including golden and Labrador retrievers, miniature schnauzers, a whippet, a shih tzu, and a bulldog—and it was determined that all of the dogs had eaten food containing potatoes, peas, or lentils.

While heart disease is common in large dogs like Great Danes and Saint Bernards, it’s less common in small and medium-sized breeds (with the exception of cocker spaniels). If caught early enough, a dog’s heart function may improve with veterinary treatment and dietary changes, the FDA notes. While the department is still investigating the potential link, it’s best to err on the side of caution and avoid foods containing these ingredients until further notice.

As shown by the recent romaine lettuce scare linked to E. coli, the FDA is unable to request a food recall unless a specific manufacturer or supplier can be identified as the source of contamination. Instead, public notices are generally issued to warn consumers about a certain food while the agency continues its probe.

[h/t Time]

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10 Science-Backed Tips for Getting a Cat to Like You
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Like so many other humans, you might find cats to be mysterious creatures. But believe it or not, it’s not that hard to make friends with a feline, if you know what to do. Here are some tips on how to effectively buddy up with a kitty, drawn from scientific studies and my own experience as a researcher and cat behavioral consultant.

1. LET THE CAT CALL THE SHOTS.

When we see cats, we really want to pet them—but according to two Swiss studies, the best approach is to let kitty make the first move.

Research done in 51 Swiss homes with cats has shown that when humans sit back and wait—and focus on something else, like a good book—a cat is more likely to approach, and less likely to withdraw when people respond. (This preference explains why so many kitties are attracted to people with allergies—because allergic people are usually trying to not pet them.) Another study found that interactions last longer and are more positive when the kitty both initiates the activity and decides when it ends. Play a little hard to get, and you might find that they can’t get enough of you.

2. APPROACH A CAT THE WAY THEY GREET EACH OTHER (SORT OF).

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Felines who are friendly with each other greet each other nose to nose. You can mimic that behavior by offering a non-threatening finger tip at their nose level, a few inches away. Don’t hover, just bend down and gently extend your hand. Many cats will walk up and sniff your finger, and may even rub into it. Now that's a successful greeting.

3. PET CATS WHERE THEY LIKE IT MOST …

They're very sensitive to touch, and generally, they tend to like being petted in some places more than others. A small 2002 study demonstrated that cats showed more positive responses—like purring, blinking, and kneading their paws—to petting on the forehead area and the cheeks. They were more likely to react negatively—by hissing, swatting, or swishing their tails—when petted in the tail area. A more recent study validated these findings with a larger sample size—and many owners can testify to these preferences.

Of course, every animal is an individual, but these studies give us a good starting point, especially if you're meeting a cat for the first time.

4. … AND IF YOU GET NEGATIVE FEEDBACK, GIVE THE CAT SOME SPACE.

There are plenty of signs that a cat doesn't like your actions. These can range from the overt—such as hissing and biting—to the more subtle: flattening their ears, looking at your hand, or twitching their tails. When you get one of those signals, it’s time to back off.

Many of the owners I work with to correct behavioral issues don't retreat when they should, partially because they enjoy the experience of petting their cat so much that they fail to recognize that kitty isn’t enjoying it too. You can’t force a feline to like being handled (this is especially true of feral cats), but when they learn that you’ll respect their terms, the more likely they will be to trust you—and come back for more attention when they're ready.

5. DON’T OVERFEED YOUR CAT.

Many think that food equals love, and that withholding food might make your kitty hate you, but a recent study of obese felines from Cornell University showed the opposite is true—at least for a period of time. About a month after 58 overweight kitties were placed on a diet, three-quarters of their owners reported that their dieting felines were more affectionate, purred more often, and were more likely to sit in their owner's lap. This adorable behavior came with some not-so-cute side effects—the cats also begged and meowed more—but by week eight, both the good and bad behavior had abated for about half the animals.

Regardless of whether a diet makes your pet cuddlier, keeping your pet on the slender side is a great way to help them stay healthy and ward off problems like diabetes, joint pain, and uncleanliness. (Overweight animals have difficulty grooming themselves—and do you really want them sitting on your lap if they can’t keep their butt clean?)

6. PLAY WITH THEM—A LOT.

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Most of the behavior problems that I've witnessed stem from boredom and a lack of routine playtime. No one thinks twice about walking their dog every day, but many people fail to recognize that felines are stealth predators who need a regular outlet for that energy. A recent study suggested that cats prefer human interaction over food, but a closer look at the data demonstrated that what really attracted them to humans was the presence of an interactive toy. One of their top choices is a wand-style toy with feathers, strings, or other prey-like attachments that evoke predatory behavior. Daily interactive play is a great way to bond with them when they’re not in the mood to cuddle—and to keep them fit. Try the Go-Cat Da Bird or any of Neko Flies interchangeable cat toys.  

7. KEEP YOUR CAT INDOORS.

A study conducted in Italy showed that felines who stayed mostly indoors (they had one hour of supervised access to a small garden each day) were more “in sync” with their owners than felines who were allowed free access to the outdoors. The indoor kitties were more active during the day, when their owners were likely to be active, and less active at night, when humans like to sleep. (Many people believe cats are nocturnal, but they are naturally crepuscular—active at dawn and dusk.)

8. SOCIALIZE CATS WHEN THEY'RE YOUNG.

Multiple studies have shown that just a few minutes a day of positive handling by humans helps kittens grow up to be friendlier and more trusting of humans. The ideal age to socialize kittens is when they're between 2 and 9 weeks old. One 2008 study found that shelter kittens that had been given a lot of "enhanced socialization"—additional attention, affection, and play—were, a year later, more affectionate with their owners and less fearful than other kittens adopted from the same shelters.

You can help socialize kittens by volunteering as a foster caretaker. Fostering ensures they get plenty of interaction with people, which will help them will be comfortable around potential adopters. You'll also be doing your local shelter a huge favor by alleviating overcrowding.

9. TAKE THE CAT'S PERSONALITY—AND YOUR OWN—INTO CONSIDERATION WHEN ADOPTING.

If you want to adopt an older animal, take some time at the shelter to get to know them first, since adopters of adult cats report that personality played a big role in their decision to take an animal home permanently and had an impact on their satisfaction with their new companion. Better yet, foster one first. Shelters can be stressful, so you'll get a better sense of what an animal is really like when they're in your home. Not all cats are socialized well when they're young, so a cat may have their own unique rules about what kinds of interactions they're okay with.

It's also key to remember that a cat's appearance isn't indicative of their personality—and it's not just black cats who get a bad rap. In 2012, I published a study with 189 participants that showed that people were likely to assign personality traits to felines based solely on their fur color. Among other things, they tended to think orange cats would be the nicest and white cats the most aloof. (Needless to say, these are inaccurate assumptions.) And it's not just the kitty's personality that matters—yours is important too. Another study I conducted in 2014 of nearly 1100 pet owners suggested that self-identified “cat people” tend to be more introverted and anxious when compared to dog people. (We’re also more prone to being open-minded and creative, so it’s not all bad.) If you’re outgoing and active, a more playful feline could be for you. If you prefer nights spent snuggling on the couch, a mellow, shy-but-sweet lovebug could be your perfect pet.

10. BE A KEEN OBSERVER OF THEIR BEHAVIOR.

Overall, use your common sense. Be a diligent and objective observer of how they respond to your actions. Feline body language can be subtle—something as small as an eye-blink can indicate contentment, while ear twitches might signal irritation—but as you learn their cues, you'll find yourself much more in tune with how they're feeling. And if you adjust your behaviors accordingly, you'll find soon enough that you've earned a cat's trust.

Mikel Delgado received her Ph.D. at UC-Berkeley in psychology studying animal behavior and human-pet relationships. She's a researcher at the UC Davis School of Veterinary Medicine and co-founder of the cat behavior consulting company Feline Minds.

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