(Note: This article is pretty long. If you have something to do, come back later. If you have to go to the bathroom, do it now. If you have time to kill, then read on!)
Hmm, let’s see if I can whip up another one of these. I’m starting to get a feel for this again. :D Let's set forth on our everlasting journey of knowledge with Dr Guy's suggestion from a long time ago, the all too popular, loveable........
Domestic Dog Canis lupus familiaris
From the family Canidae, which includes dogs, wolves, foxes, coyotes, dingoes, jackals, and lycaons(African wild dogs). The members are referred to as canids or canines. You may notice the trinomial description up there. Dogs have been classified as a subspecies of wolf, (Canis lupis) so that's the reason for that.
There are a lot of dog breeds so it’s hard to get too specific.
This is a dog. A boxer, to be exact. I have one of these.
Physical Characteristics:
Dogs are highly variable in height and weight, no surprises there. The extreme ranges(world record holders, actually) are as follows: The smallest known dog was a Yorkshire Terrier, who stood only 2.5 in (6.3 cm) at the shoulder, 3.75 in (9.5 cm) in length along the head and body, and weighed only 4 oz(113 g ). The heaviest and longest known dog was an English Mastiff which weighed 155.6 kg (343 lbs) and was 250 cm (8.2 feet) from the snout to the tail. The tallest dog is a Great Dane that stands 42.2 in (106.7 cm) at the shoulder.
Keep in mind these sizes are exceptional. On a breed basis Irish Wolfhounds rank as the largest dog,
Someone’s shag carpet got loose.
Chihuahuas as the smallest dog
“Yo soy un perro pequeño.”
and the St. Bernard as the heaviest dog.
“Call me fat and you get your own damn self out of the snow.”
Coat color can be any color and combination you can think of…well, within normal hair color. Don’t expect neon pink dogs(unless some crazy owner has a field day with dye). Hair can be long, short, curly, straight, rough, soft, and/or nonexistent in hairless dogs.
Ears can be drooping or erect. The muzzle and snout can be elongated or flattened. Tails are often present in dogs, the Schipperke is a breed that lacks a tail. Tails can be curly, straight, long or short.
As I said, real hard to narrow down specific phenotypic traits. Due to human breeding the species is a mosaic of colors, shapes, and sizes.
The shared traits between the breeds are easier to expound upon.
Compared to equally sized wolves dogs tend to have 20% smaller skulls and 10% smaller brains, as well as proportionately smaller teeth. It’s thought that through domestication the size of the brain and skull were reduced because they were no longer needed for the rigors of hunting. They also require fewer calories in order to function than wolves.
Like wolves, and all predatory mammals, dogs possess strong muscles and cardiovascular system able to keep up with stress required for endurance, sprinting, and all the lovely things predators do. The teeth are strong and designed for the pleasant task of catching, holding, and tearing flesh. Dogs have an average bite pressure of about 320lbs(averaged from a German Shepherd, American Pit Bull Terrier, and Rottweiler)…a human can only produce 120lbs.
The skeletal structure is made for running and leaping. Dogs have disconnected shoulder bones (no collar bone) that give a greater stride length. The rear legs are fairly rigid and sturdy; the front legs are loose and flexible. The feet are small and tight. By the way, dogs are always walking on their toes. The toes, of course, have pads on them made up of various sciencey words(I’ll spare you. :) ) that amount to fatty, squishy things that act as shock absorbers and help with traction. Each toe also has a single claw. There are 4 toes on each foot and in some breeds a 5th toe farther up on the leg called a dewclaw.
A. Claw, B. Digital Pads, C. Metacarpal Pad, D. Dew Claw, E. Carpal Pad. (More than you care to know about a dog’s foot.)
Dogs, like most mammals, have dichromatic vision which is equivalent to red-green colorblindness in humans.
Dogs with long noses have a "visual streak" which runs across the width of the retina and gives them a very wide field of excellent vision, while those with short noses have an "area centralis" - a central patch with up to three times the density of nerve endings as the visual streak - giving them detailed sight much more like a human's.
Some breeds have a field of vision up to 270° (compared to 180° for humans).
Sight is movement based as you would expect from a predator. Being typically crepuscular hunters, their eyes are adapted for low light situations and so have one of those tapetum lucidum (shiny surface behind the retina) in each eye.
The tapetum lucidum makes the eye glow…either that or a demonic power. It’s one or the other.
As you know, their ears are pretty powerful. Dogs detect sounds between 40 Hz to 60,000 Hz. Combine that with 18 or more muscles that control a dog’s ear and the ability to detect a sound 4 times farther away than a human and they can pinpoint a sound like no one’s business. Dogs with erect ears usually hear a bit better than floppy eared varieties. They hear all!
The legendary dog nose is bolstered by an olfactory cortex dominated brain. The olfactory bulb in dogs is 40 times larger than in humans relative to total brain size with 125 to 220 million smell-sensitive receptors. The bloodhound, specially bred for sniffing stuff out, exceeds this standard with nearly 300 million receptors. Dogs can discriminate odors at concentrations nearly 100 million times lower than humans can. They can find a fart in a windstorm. :P Though they tend to be utilized for drug sniffing and finding people. Some dogs can even sniff out cancer.
As for touch and taste, they’re not that impressive. Dogs are not connoisseurs, but they do love a good petting. :D
Habitat:
Urban, rural…wherever there’s people or where people used to be. Dogs are domestic and thus stick with humans the whole way. If there are people, there are usually dogs.
If dogs are outside they may sleep in one of these:
“Get off my lawn! I need to poop on it.”
If inside, they will often improvise:
I think I’ve slept like this a couple times.
Diet:
Omnivorous. You’d expect carnivore, wouldn’t you? Though they are descended from wolves and classified in the order Carnivora, dogs can healthily digest a variety of stuff including vegetables and grains and can eat a large portion of them in their diet. They’re not dependent on meat-specific proteins or a very high levels of protein. They do need a bit, but they’re not obligate carnivores. Dogs are able to healthily digest a variety of foods, including vegetables and grains, and can consume a large portion of these in their diet.
One thing they SHOULD NOT HAVE is chocolate. Chocolate contains theobromine, a stimulant similar to caffeine. Humans can metabolize it fairly quickly, animals are slower thus leading to theobromine poisoning from as little as 50 grams of chocolate for a smaller dog and 400 grams for an average-sized dog. Complications include digestive issues, dehydration, excitability, and a slow heart rate. Later stages of theobromine poisoning include epileptic-like seizures and death. If caught early on, theobromine poisoning is treatable.
Mmm, meat!
Mmm, veggies!
Normally it ends up like this where you really can’t tell what the hell it is.
Behavior:
Originally crepuscular they end reflecting their owner’s habits and as most people are awake during the day, they’re diurnal. I mean, would you stay awake when there’s no one to play with?
Dogs are traditionally a social animal, though some breeds are more independent than others. The social unit is a pack and within it there are rankings resulting in a social hierarchy. The fact that wolves have complex hierarchies probably led to the ease at which dogs have been domesticated and integrated into our society. Training dogs is easy due to their social tendencies in a pack environment. They respond best to operant conditioning (positive or negative reinforcement when a behavior is performed). As with everything in dogs, some breeds are better than others when it comes to training…some get it quickly, others don’t really give a damn what you say. Being social animals, they can experience separation anxiety when left alone which leads to them howling and tearing stuff up.
The dominant/submissive model has been fairly popular in understanding dog social structure.
Displays of dominance have been observed to include "licking up," which involves essentially begging for food(this is moreso in wolves); "pinning," in which the dominant dog appears to threaten another, which shows submission by rolling over; "standing over;" territorial marking; and more passive expressions of body language, including holding the tail and ears erect, looking directly at other dogs, circling and sniffing other dogs, growling if the other dog moves.
Who’s my bitch?
Submissive displays mirror dominant displays and include adopting a posture that is physically lower than other dogs, such as crouching, rolling over on the back and exposing the abdomen, lowering the tail (sometimes to the point of tucking it between the legs), flattening of the ears, averting the gaze, nervously licking or swallowing, dribbling of urine, and freezing or fleeing when other dogs are encountered.
Aside from that dogs have other ways to communicate. Greetings, for instance, often involve a good round of ass sniffing to help the dogs get a better idea of each other through the various odors they have. Humans can get in on the greeting action by substituting their hand in place of an ass to sniff.
“Your ass, it smells wonderful!”
Affection behaviors include the following: wagging the tail, licking, playful barking, panting, or jumping. Dogs that show affection in this way will usually get along fairly well, and this display can be considered a display of friendship.
Fear and/or aggression are often displayed as snarls, growls, baring of teeth, crouching, ears back across the head, bristled tail(if tail is present) and tense posture.
The tail comes in handy for a multitude of emotions. A highly carried tail shows the dog is alert, one tucked down shows fear or submission. A wagging tail can be interpreted a number of ways depending on the vocal and other body cues. Small, slow wags of the tail says the dog is questioning things around them. Large, fast wags of the tail is a sign of a happy or excited dog. If the wags are large enough to pull the dog's hips with them, the message includes a bit of submission to someone they view as pack leader. Dogs with docked tails tend to have some problems communicating with other dogs, since their tail movements are extremely difficult to detect. Dogs with docked tails will usually compensate for this by wagging the whole doggy booty.
Ears are also important in communication. Ear position relates the dog's level of attention, and reaction, to a situation or animal. Erect ears facing forward means the dog is very attentive, while ears laid back suggests a negative, usually fearful or a timid reaction. They also lay their ears back for the sounds surrounding them. Dogs with drop ears can't use these signals very well. Wolf-like dogs (such as the Samoyed or Husky) will, when content and happy, often hold their ears in a horizontal position but still forward. This has been referred to as the "wolf smile".
Dogs also have a host of vocalizations including barking, howls, growls, whimpers, and whining. Barks are pretty variable in their meaning: loneliness, fear, suspicion, stress, pleasure. Howls are primarily used for long distance communication. They’re also prominent when a dog is left along and experiencing separation anxiety. Growling, as you might guess, is aggressive but may also be used playfully. Whimpers can indicate injury or some form of distress. Whining is self explanatory…the dog wants something.
As you may know, dogs like to play. When dogs play with each other it’s primarily made up of mock fights. It is believed that this behavior, which is most common in puppies, is training for important behaviors later in life. Research on puppy play has shown that puppies do not engage equally in both dominant and submissive roles in fights; rather, puppies will tend to start play fights with weaker puppies they believe they can dominate. *cough*assholes*cough*
“I challenge you to a duel, Sir!”
Dogs don’t have a breeding season, but the female, or bitch if you prefer, will come into estrus biannually. There’s no real courtship behavior aside from sniff, sniff, female presents, male mounts. An interesting thing during mating is that the bulbis glandis located at the base of the penis will swell and result in a coital tie thus locking the two together for 5-60 minutes. During this time the male will hop around and face away from the female so they’re “back to back” as illustrated by this helpful non-explicit diagram:
Don’t ever Google anything about mating with SafeSearch off. Holy crap.
It should be noted that all dogs can theoretically breed with each other because they’re the same species. However, due to certain morphological constraints not all breeds can crossbreed. A St. Bernard for instance would kill a Chihuahua in a horrifying, yet comical way.
After the doggy magic happens it takes an average of 63 days for the female to give birth(whelping). For small breeds litter size is small, usually around 2-4 pups, larger breeds can have around 10 or more. Puppies are blind at birth and will open their eyes between 7 and 14 days. They can be introduced to gruel(water/puppy food) at 3-4 weeks of age and by week 7 should be able to eat dry food and can be weaned at that time. Sexual maturity kicks in at around six to twelve months for both males and females, although this can be delayed until up to two years old for some large breeds. The average dog lives 8 to 15 years.
PUPPIES!!!
According to the Humane Society of the United States, 3-4 million dogs and cats are put down each year in the United States and many more are confined to cages in shelters because there are many more animals than there are homes. Spay or castrate your goddamn pets, people! Well, not you personally. Take’em to a vet.
Interesting Facts:
-The basenji, an African breed, is the only dog that cannot bark. It yodels, grows, and howls.
-Laika became the world's first space traveler. Russian scientists launched her into space in Sputnik 2 in 1957. She became the first orbital casualty a few hours after launch probably from stress and overheating brought on by a malfunction in the thermal control system.
The furry cosmonaut.
-Cerberus, the three-headed dog of Greek mythology, guarded the gates to the underworld.
-The normal body temperature for a dog is 101.2 °F (38.4 °C).
-The oldest age recorded for a dog is 29 years, 5 months for a Queensland 'heeler' called Bluey in Victoria, Australia.
-A dog's whiskers are touch-sensitive hairs called vibrissae(see my
cat article for more on those.)
-An American Animal Hospital Association poll showed that 33 percent of dog owners admit that they talk to their dogs on the phone or leave messages on an answering machine while away.
-An estimated 1 million dogs in the United States have been named the primary beneficiary in their owner's will.
-At the end of the Beatles' song "A Day in the Life", an ultrasonic whistle, audible only to dogs, was recorded by Paul McCartney for his Shetland sheepdog.
-Every known dog except the chow has a pink tongue - the chow's tongue is jet black.
-Inbreeding causes 3 out of every 10 Dalmatian dogs to suffer from hearing disability.
-Korea's poshintang - dog meat soup - is a popular item on summertime menus, despite outcry from other nations. The soup is believed to cure summer heat ailments, improve male virility, and improve women's complexions.
-Pekingese dogs were sacred to the emperors of China for more than 2,000 years. They are one of the oldest breeds of dogs in the world.
-The Canary Islands were not named for a bird called a canary. They were named after a breed of large dogs. The Latin name was Canariae insulae - "Island of Dogs."
-The first seeing-eye dog was presented to a blind person on April 25, 1938.
-The Fédération Cynologique Internationale (World Canine Organization) recognizes over 400 dog breeds.
Whew…that was a lot. Hope you guys had fun. :D
~Zoo