Dogs can smell electricity. Cats may have the power to hypnotize birds. Kittens contact their mothers via a secret, ultrasonic language. Dogs can understand a vocabulary of 200 human words. Every day, new scientific discoveries are fuelling the age-old argument about which of man’s two best friends really is the superior species. Augustus Brown fans the flames further with this collection of the weirdest, most wonderful and downright incredible truths about cats and dogs. Did you know, for instance, that dogs can see moving objects 900 yards away, and that cats can sense earthquakes coming? Or that dogs prefer Bach to Britney, while cats prefer drugs to chocolate? And who would have thought that cats are inspirational pianists, or that there’s a reason why dogs simply can’t stop themselves howling – tunelessly – along. Fascinating, funny and provocative, his book may not settle the debate once and for all but it is certain to set cat and dog lovers arguing like, well, you know what …
Augustus Brown is the author of Why Pandas Do Handstands, a collection of curious scientific facts about the animal kingdom in general. In this, his second book, he turns his attention to cats and dogs, creatures that have intrigued him since he was a boy growing up on a Welsh farm with a German Shepherd-Sheepdog cross called Sputnik and a one-eyed tabby called Wilfred. In compiling this book, he scoured through countless scientific archives, books and studies, as well as scores of zoological and biological websites. He also consulted leading experts in the animal science world. He lives in London with his wife and two children.
Cover
About the Book
Title Page
Dedication
Preface
PART ONE: SENSE AND SCENT ABILITY: HOW CATS AND DOGS SMELL, HEAR, SEE AND FEEL
You Stink, Therefore I Am: How Cats and Dogs Smell
The Cat’s Whispers: How Felines and Canines Tune In to the World Around Them
What’s Blue, Pussycat?: How Cats and Dogs See
I Feel Kitty: How Cats and Dogs Touch and Feel
Is It Raining, Cats and Dogs?: Canine and Feline Superpowers
PART TWO: WHAT’S THE DOG FOR CAT?: THE CURIOUS TRUTH ABOUT CANINE AND FELINE COMMUNICATION
Snap, Gurgle and Puff: Pet Sounds and What They Really Mean
Have I Got Poohs for You: How Actions Speak Louder Than Words
PART THREE: WHO’S A CLEVER BOY, THEN? SOME TRUTHS ABOUT CANINE AND FELINE INTELLIGENCE
Dogs Remember, Cats Don’t Forget: Mental Agility
One, Two, Three o’Clock, Four o’Clock – Snack: How Cats and Dogs Count, Tell the Time and Do Calculus
Not-so-dumb Mutts: Some Other Curious Feats of Canine and Feline Intelligence
PART FOUR: IS SHE REALLY GOING OUT WITH THEM? THE TRUTH ABOUT CAT AND DOG RELATIONSHIPS
While the Tomcat’s Away, the Wife’s at Play: Cats, Dogs and the Mating Game
Heavy Petting: Some Truths About Cat and Dog Sex
Whelp! How Cats and Dogs Cope with Birth and Beyond
PART FIVE: EATS GOATS AND LEAVES: CANINE AND FELINE FOOD AND DRINK
Cats Snack, Dogs Have Dinner: Why Both Are What Their Ancestors Ate
Kangaroo and Tortoise Eggs: What Cats and Dogs Eat in the Wild
Rex and Drugs: How Cats and Dogs Get High
PART SIX: HOW LASSIE COMES HOME AND TOM ALWAYS LANDS ON HIS FEET: CATS AND DOGS IN MOTION
Making Tracks: How Cats and Dogs Put One Paw in Front of Another
They Fly Through the Air with the Greatest of Ease: How Cats and Dogs Defy Gravity
The Lassie Principle: How Cats and Dogs Usually Find Their Way Home
Fat Cats Can’t Jump: Why Some Cats and Dogs Don’t Get Around So Well
PART SEVEN: THE CAT PACK: THE SOCIAL LIVES OF CATS AND DOGS
12.4 Children: The Family Life of Cats and Dogs
Leaders of the Pack: How Cats, Dogs and Other Animals Live Together
Bosom Buddies: How Cats and Dogs Evolved into Man’s Best Friends
Soul Mates: Why Cats, Dogs and Humans Are Made for Each Other
PART EIGHT: DR LABRADOODLE: HOW CATS AND DOGS HAVE BECOME BREEDS APART
Cats Aren’t From Mars: Some Odd Truths About Cat and Dog Breeds
Some Pets Get All the Bad Luck: Breeds That Draw the Genetic Short Straw
You Are What You Wear: How Cats and Dogs Are Colour-Coded
PART NINE: IT’S A CAT AND DOG’S LIFE: SOME CURIOUS TRUTHS ABOUT CANINE AND FELINE LIFESTYLES
All That Litters: Personal Hygiene in Cats and Dogs
Bite Me: How Cats and Dogs Play
The Joy of Rex: Some Things That Make Cats and Dogs Happy (and Sad)
Play It Again, Tom: When Cats Play Piano, Dogs Howl Along
Let Sleeping Dogs Snore: How Cats and Dogs Catch Forty Winks
Afterword
References
Acknowledgements
About the Author
Also by Augustus Brown
Copyright
Ever since our favourite two animals first sidled up to our campfires 15,000 or so years ago, we humans have harboured all sorts of curious notions about cats and dogs.
In ancient Greece, for instance, dogs were regarded as geniuses. Plato, no less, called his dog ‘a lover of learning’ and ‘a beast worthy of wonder’, while Socrates once made an impassioned speech arguing that his pet was ‘a true philosopher’.
Ancient Egyptians were in such awe of the self-contained and seemingly indestructible cat that they regarded it as a living god, to be worshipped accordingly. Travelling through Egypt, the historian Herodotus couldn’t believe his eyes when he saw people lined up outside a row of blazing houses, all of them more concerned about stopping their cats getting too near the flames than they were anxious to save their belongings from going up in smoke.
Even until quite recently people associated both animals with extraordinary powers. As late as the nineteenth century the Chinese reckoned they could tell the time of day by the colour and intensity of the glow in a cat’s eyes. In Eastern Europe some believed you could cure consumption by eating the flesh of a cat and wearing its skin on your chest. According to another old wives’ tale from Greece, if you are about to choke on a bone you should let an unweaned puppy give you the kiss of life (unless it is a fishbone, in which case you should apply an unweaned kitten).
For many years science left dogs and cats to it, reserving its serious study for creatures in the ‘natural’ world rather than the ‘man-made’ ones that lay sleeping by our hearths. It was only towards the end of the twentieth century that biologists, zoologists, geneticists, ethologists and assorted other animal experts finally turned their attention to the most familiar members of the animal kingdom. When they did so, they discovered that cats and dogs are every bit as extraordinary as our ancient ancestors imagined them to be. Socrates, for certain, wouldn’t have been amazed to learn that dogs do mathematics complex enough to have made even Pythagoras’s head spin. Old wives across Europe would have nodded knowingly at the news that cats and dogs might possibly help humans manage illnesses from high blood pressure to asthma and epilepsy.
Eye-popping new insights into man’s two best friends are now emerging on a regular basis. Thanks to DNA research, we know more than ever about who they are, where they came from, and how they think and behave. Today, for instance, we know that dogs are more closely related to sea-lions than they are to cats. We have evidence that cats and dogs may be able to sniff cancer and predict impending earthquakes, navigate huge distances using electromagnetism, perform impressive feats of memory and even create works of music and art.
This book is a collection of some of the weird, wonderful and occasionally unbelievable things we currently know about the two species. As with my previous book, Why Pandas Do Handstands, I’ve applied a simple principle to collating them. It is a collection intended to inform and educate but to entertain too. Consequently, while I have once more been scrupulous in providing sources for those who may want to dig deeper, I have again refused to let pedantry get in the way too much.
So here they are in all their curious glory, felis silvestris catus and canis familiaris, better known to you and me as Kitty and Rover.
NO WONDER OUR ancient ancestors recruited cats and dogs on to their domestic staff. Like four-legged FBI agents, they are armed with super-sensitive surveillance equipment capable of tracking down prey and providing early-warning systems to fend off predators.
Dogs, it seems, are capable of sniffing everything from electricity to ovulating animals, while cats can operate in pitch dark and tune in to the ultrasonic singing of even the quietest of mice. And it doesn’t end there: both seem capable of predicting everything from hurricanes to earthquakes, epileptic fits to cancers.
DOGS CAN SMELL human fingerprints that are a week old.1
Their noses are so sensitive that they can even smell electricity.2 While conducting an experiment, a researcher found that a dog could smell which of two compartments contained an electric current. He concluded this was because the charge resulted in the release of tiny amounts of ozone that the dog could detect.
DOGS CAN tell from the smell of a cow’s urine whether it is in oestrus, or heat.3 Farmers train them to do this so they know the best time to introduce a bull for breeding.
SMELL IS the first sense that a cat develops.4 It can pick up the aroma of its mother’s mammary glands at birth and within two days is reacting to odours that it finds offensive. Among the things it can learn to dislike, if exposed to the smell of them early on, are mothballs.
THE NOSE pad of a cat is ridged in a pattern that is unique, just like the fingerprint of a human.5
DOGS REALLY can smell fear.6 If a dog goes into a room where a frightened dog has just left, it will appear anxious and agitated. This isn’t, as many would claim, some kind of ESP-type response. It’s caused by a scent, an alarm pheromone, which is produced by the anal glands of frightened dogs.
DOGS CAN detect odours that are up to 40 feet underground.7 They have been used to detect leaky gas pipes. They can also smell insects embedded in the ground or in woodwork. In the United States dogs are used to sniff out termite infestations.
DOGS CAN also pick up the faintest whiff of other creatures. On the island of Guam, the US Department of Agriculture’s Wildlife Services use specially trained Jack Russells to sniff out brown tree snakes in the loading bays of aeroplanes.
THE SOURCE of the dog’s exceptional ability to smell is its wet snout.8 The moist leathery surface of the snout acts like velcro, catching even the tiniest molecules of smells, then dissolving them so that the dog’s internal smell-receptor cells can analyse them properly. To keep its nose wet a dog must produce a constant supply of mucus through the nasal cavities. Scientists reckon the average dog produces a pint of this mucus every day.
SMELL IS the dog’s dominant sense – so much so that a huge part of its brain is devoted to analysing odours.9 Dogs have two giant olfactory bulbs attached to the brain that decode every smell they encounter. The bulbs weigh around 60 grams, four times as much as human olfactory bulbs. Given that a canine brain is one tenth the size of a human one, that means the canine has forty times more of its brain devoted to smell than we do.
Little wonder, then, that a dog’s sense of smell is reckoned to be 100,000 times better than a human’s. In tests dogs have been able to pick up chemical solutions that form one or two parts in a trillion. That is the equivalent of smelling one bad apple in two billion barrels.
THE CAT’S olfactory bulb contains 67 million cells.10 This is less than a dog’s, which has hundreds of millions. But it is 15 million more than a human’s has.
A YOUNG kitten that becomes distressed by being removed from its litter will automatically crawl towards anything that carries the smell of its former home and fall asleep.11
BOTH DOGS and cats have an extrasensory organ located between the nose and the mouth.12 Called the vomeronasal organ, it detects chemicals in a similar way to the nose, but unlike the nose it must usually be in direct contact with the chemical. Dogs and cats probably use it to recognize each other’s smell, among other things. (Interestingly, the human foetus also has a version of this organ, but it regresses during development and most scientists think that it doesn’t function at all in adults.)
DOGS REACT in different ways to different smells.13 In tests, for example, it has been found that dogs relax when the aroma of lavender is fed into their environment. Camomile also makes dogs calmer. Rosemary and peppermint, on the other hand, make dogs more excited.
CATS ALSO respond to different smells.14 The smell of nutmeg makes them less bored, researchers discovered.
In general, cats prefer to be in an environment with lots of smells. Even the odour of animals that are traditionally their prey relieves their boredom.
AS FAR as dogs are concerned, every human has a unique smell.15 They can pick people out according to their body, and other, odours. Scientists think the only occasion a dog can’t tell two people apart is if they are identical twins on identical diets who remain silent.
As a result of this, dogs can track human smells over long distances.16 Scientists think they can pick up on the difference in odours from different footprints to work out which direction their prey is headed. They can do this twenty minutes after a person has passed by even though the footprints are made a single second apart.
Scientists who tested four German Shepherds discovered they track footprints by dividing the job into three phases.17 During the first, search phase they move quickly, sniffing ten to twenty times each breath. Once they have detected the smell they enter the deciding phase, when they sniff at between two and five specific footprints. They do this for a longer period, slowing down as they do so. Finally, once the direction has been established, the tracking phase begins.
THE REASON why dogs have black noses was probably originally to protect them from sunburn.18
CATS HAVE MORE than twenty muscles in their external ears, or pinnae.1 As a result they can move each ear independently of the other, using them to identify rapidly and also to amplify sounds. They can also move their bodies in one direction while pointing their ears in another.
CATS CAN pinpoint the source of sounds with amazing accuracy.2 From 1 metre away, a cat can tell the difference between two identical sound sources that are only 8 centimetres apart.
CATS ARE capable of hearing a greater range of frequencies than virtually any other mammal.3 A cat can hear across 10.5 octaves, in comparison with a human’s range, which is nearer 8 octaves. They can hear between 35 kilohertz and 250 kilohertz. This means they can even detect the ultrasonic sounds made by rodents. This is why they sometimes locate and pounce on a mouse without actually seeing it in advance.
THE ADULT cat’s ability to distinguish other animals’ sounds is so highly developed that scientists think it can tell the difference between the squeak of a mouse and that of a shrew.4
MANY OWNERS think their cat somehow senses their arrival home in the family car.5 The truth is more likely to be that its ultrasonic hearing allows it to recognize the signature high-frequency sound of the owner’s car well in advance of its arrival within human earshot.
USING THEIR swivelling ears like radar dishes, dogs can locate the source of a sound in 6/100ths of a second.6 They are able to hear sounds 250 yards (230 metres) away that a human would only detect at 25 yards (23 metres). Depending on the volume of the noise, the upper limit of a dog’s hearing varies between 26 kilohertz and 100 kilohertz, well above a human’s upper limit.
DOGS CAN hear both ultra- and subsonic sound.7 Bigger dogs with larger heads and wider ear openings tend to be better at hearing subsonic sounds, which is why breeds like the Saint Bernard are so good at hearing deep, low-resonance noises emanating from underneath snow. Smaller dogs are better at hearing high-frequency sounds, which is why smaller breeds are more sensitive to high-pitched noises.
BECAUSE OF ITS history as a predator, the dog has eyes that are designed to operate at their best in low lighting.1 As with humans’, their retinas are made up of a mixture of rod and cone photoreceptors, but with the emphasis more on rods, which work much better in dim light. Cones control colour vision and require bright light.
As a result of this, dogs need only about one quarter of the light that humans do to see things at night.
THE CAT too has evolved from a predator, and retains many of the characteristics that makes its closest animal relatives, the big cats, among nature’s most efficient and ruthless hunters.
The elliptical pupil of a cat’s eye allows it also to see in a greater range of light conditions than we can.2 In addition, its slitty shape means that cats can squint better than those of us with round eyes, allowing them to protect their eyes better in bright light. This cleverly designed instrument has another smart feature too. Rather than just one focal point in their lens, cats have several, which means that, unlike humans, they still get a very sharp image in low light.
CAT’S EYES shine when they get caught in the beam of a light.3 This is because of a mirror-like membrane at the back of the retina called the tapetum lucidum, which reflects the light back through the retina. This, combined with the efficiency of their elliptical pupils, means they need only a seventh of the light required by humans to see in the dark.
CATS CAN be used as rudimentary clocks.4 The colour and glow of the pupils of cats’ eyes change according to the course of the sun.
SIAMESE CATS are often born with double vision.5 This is why they squint. It is their way of trying to correct what is a genetic defect.
CATS HAVE great peripheral vision.6 This means that in good light they rarely need to focus. Instead they remain wide-eyed, looking as if they are staring into space. This is probably why cats seem so aloof.
THE CAT family is reckoned to have the best binocular vision of all mammals.7 The position of their eyes, placed at the front and high up on the skull, allows them to judge distances with great accuracy.
DOMESTIC CATS are slightly near-sighted.8 Feral cats, however, tend to be long-sighted.9 No one has yet explained why.
CATS HAVE a blind spot, right under their nose.10 This explains why they can’t find tidbits on the floor.
DOGS AREN’T colour-blind; they just don’t see the range of colours that other species, such as humans, do.11 A study of dogs concluded that they see a range of colours predominantly made up of yellows and blues. So rather than a rainbow of red, orange, yellow, green, blue, indigo and violet, a dog sees an arc of very dark grey, dark yellow or brown, light yellow, grey, light blue and dark blue.
WHEN PRESENTED with different shades of grey, dogs are only about half as good as humans at telling the difference between them.12
CATS CAN see limited amounts of colour.13 The central area of their retinas has a patch of cones that is capable of detecting colour in daylight conditions. Experiments have shown that they can see green, blue and possibly red. However, scientists think the colours are much less saturated than those we humans can see.
DOGS CAN detect flickering lights at a high frequency.14 Unlike humans, for whom flashing lights blend into one at a frequency of between 50 and 60 hertz, dogs can keep seeing flickering up to a frequency of 70 hertz. This is why they don’t always show much interest in television, which – at least, in its pre-digital form – consists of a series of fast-moving lines. What appears to us as a steady stream of images appears to them as little more than a rapidly flickering and generally meaningless collection of shapes and lights.
BOTH CATS and dogs are equipped with windscreen wipers.15 The canine and feline eye is equipped with a third eyelid – also known as the haw or nictitating membrane – which automatically moves up and down, sweeping the eye clean on a regular basis. The third eyelid isn’t normally visible but if the gland attached to it is inflamed it can show as a red swelling. (Hence the condition’s nickname when dogs suffer it: ‘cherry eye’.)
DOGS HAVE, on average, 20 : 75 vision – that is, they can see only from a distance of 20 feet fine details that a person with good eyesight can see from 75 feet away.16
DOGS HAVE a large blind spot behind their heads.17 The size of this depends on the size of the dog’s head and so varies enormously from breed to breed. While the blind spot in a narrow-headed Borzoi is only 70 degrees, in the wider-headed Pekingese it is 140 degrees, leaving it much more vulnerable to attacks from behind.
DOGS ALSO don’t have great ‘depth of field’ to their vision.18 Because they have such large pupils, when they look at things that are distant they see only the objects in the centre of the image in focus. Everything else in the image appears fuzzy.
WHILE DOGS may not be able to see behind them or in fine detail, they can see things at great distances – especially if they are moving.19 A test of fourteen police dogs found that they could recognize a moving object almost 1/2 mile (900 metres) away; if it was stationary, just over 600 yards (585 metres).
CATS’ AND DOGS’ sense of touch is concentrated around their snouts, where they both have four sets of highly sensitive whiskers, or vibrissae.1 The vibrissae are positioned next to the snout and the eyes, in front of and below the ears. Dogs have an extra set of vibrissae, called the inter-ramal tuft, which is positioned under the chin. Scientists think this helps them compensate for the relative weakness of their eyesight at close range and allows them to identify and pick up small objects on the floor. Cats don’t have these whiskers, probably because they tend not to carry their heads close to the ground.
Cats also have vibrissae on their front paws.2 Scientists think they were specially designed to help catch prey.
Cats use their vibrissae to determine if a space is too small to squeeze through.3
MALE DOGS tend to be left-pawed, while females favour their front right paw.4 In a study at the University of Bari, Italy, a group of eighty dogs had a piece of adhesive paper stuck to their snouts. Males tended to use their left paw to remove the paper; females used their right more often. This was backed up by another study at Queen’s University, Belfast. They tested fifty-three dogs and found the same thing.
Cats, on the other hand, are generally left-pawed.5 Studies found that 20 per cent of cats favoured their right paws when carrying out complicated, manipulatory tasks, while a little over 38 per cent favoured their left. The remaining 42 per cent were ambidextrous.
THE PADS of a dog’s feet are equipped with sensory nerves that respond to vibration.6 Researchers think this allows the dog when running to check how stable the surface beneath it is. Some scientists even think the sensors act as a speedometer, allowing the dog to measure how fast it is travelling.
PUPPIES HAVE special, heat-seeking sensors in their noses.7back