From dog biology to dog psychology, we now understand more than ever about dogs and their behaviour. Here’s what’s to know about your heart melting furry friend:
SLEEP The amount of time a dog spends sleeping depends on many factors, including his age, size, breed, health and activity level. All dogs require significantly more sleep than humans. While humans spend about 25% of their sleep in REM cycles which is the deepest and most restful stage of sleep, only about 10% of a doggy nap is in REM sleep. This means that they need to sleep longer to make up for the imbalance.
BARK Although dogs bark for a variety of reasons, biologists formerly thought that their barking didn’t change depending on the message. But now research suggests that dogs have elasticity in their vocal chords giving them the ability to slightly alter the sound of their bark to convey different meanings. Studies show differences in timing, pitch and amplitude which all vary according to context. The same is true of growling. While researchers do not yet know what these different barks and growls mean, we do know that dogs react differently to other dogs’ vocalisations depending on the context.
RUN How fast a dog can run depends on the individual dog. Running speed is largely dependent on size, body shape, and leg length, as well as the age, health and physical condition. The greyhound averages about 45 miles per hour as the world’s fastest dog. While some breeds appear to have been designed for speed, all dogs have the ability to make their bodies more aerodynamic when they run, either by flattening their ears to decrease wind resistance or pushing them back to avoid getting tripped up. The way dogs move their legs also changes when they run. A walking dog moves their right legs and left legs together, while a running dog leaps with their front legs and back legs paired, allowing for more speed.
JUMP A dog’s jumping ability depends largely on their size, strength, age, health and body condition. It has been reported that the highest jumping dogs can clear six feet, but what might be more impressive are the small breeds that can jump multiple times their body height. Another component of dog’s jumping is how far they can leap.
SIGHT A dog can see things that you and I can’t see but a dog’s vision isn’t necessarily better than a human’s. Since a dog’s eyes are positioned on the side of his head it results in greater peripheral vision, however their visual acuity or their ability to focus on objects is only about 20-40% of that of a human. This means that what a dog can distinguish as an object at 20 feet, a human with 20/20 vision could distinguish it at 90 feet. Thus, dog’s rely on their other senses a great deal to help them navigate the world.
HEARING A dog can hear a sound up to four times further away than humans. Dogs have the ability to use their ears independently and change the direction for which they are listening, which helps them zero in on the sound they are listening for. This is done because they have 18 muscles in their ears (three times as many in the human ear). Dogs also have the ability to hear different frequencies, which is why things like dog whistles can affect them so much, even when you don’t hear anything. Lastly, dogs also have the ability to practice selective hearing similar to humans, so when you are calling your dog in from the yard and it seems like they are ignoring you, there’s a good chance that they are.
EXCITEMENT When you come home at the end of a long day — or even after only an hour or two — chances are your dog is over the moon with happiness and excitement. Every! Single! Time! But why do they get so excited? There are three key factors involved. When studying brain scans of dogs exposed to certain smells, canine behavioural researchers found that the scent of a familiar human triggered the reward centres of the brain in a way that no other scent accomplished, suggesting not only that dogs know the difference between humans and other dogs, but that dogs genuinely love spending time with their humans. A study used a cognitive experiment designed for children seeing their mothers after an absence to measure the response of dogs reuniting with their owners, and found that the response is very similar. It’s important to remember that dogs are social animals that don’t like to be left alone. To them, our return signals relief from loneliness.
Dogs are one of the most diverse species on the planet. There are 218 distinct dog breeds and this doesn’t even count all the regional variations, designer cross-breeds, mixed-breeds and happy mystery mutts out there. With all of their diversity in colour, shape, size and temperament, scientists believe that dogs started diverging genetically from wolves around 27,000 years ago.