Cats(Name is Mac. Breed is a Himalayan)

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Cat[1]
Other images of cats
Conservation status
Domesticated
Scientific classification
Kingdom: Animalia
Subkingdom: Eumetazoa
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Subclass: Theria
Order: Carnivora
Suborder: Feliformia
Family: Felidae
Subfamily: Felinae
Genus: Felis
Species: F. catus
Binomial name
Felis catus
(Linnaeus, 1758)[2]
Synonyms

Felis catus domestica (invalid junior synonym)[3]
Felis silvestris catus[4]

The cat (Felis catus), also known as the domestic cat or house cat to distinguish it from other felines and felids, is a small predatory carnivorous species of crepuscular mammal that is valued by humans for its companionship and its ability to hunt vermin, snakes, scorpions, and other unwanted household pests. It has been associated with humans for at least 9,500 years.[5]

A skilled predator, the cat is known to hunt over 1,000 species for food. It can be trained to obey simple commands. Individual cats have also been known to learn on their own to manipulate simple mechanisms, such as doorknobs and toilet handles.[6] Cats use a variety of vocalizations and types of body language for communication, including meowing, purring, hissing, growling, squeaking, chirping, clicking, and grunting.[7] Cats may be the most popular pet in the world, with over 600 million in homes all over the world.[8] They are also bred and shown as registered pedigree pets. This hobby is known as "cat fancy".

Until recently the cat was commonly believed to have been domesticated in ancient Egypt, where it was a cult animal.[9] However, a 2007 study found that the lines of descent of all house cats probably run through as few as five self-domesticating African Wildcats (Felis silvestris lybica) circa 8000 BC, in the Near East.[4]

Physiology

Size

Diagram of the general anatomy of a male cat

Cats typically weigh between 2.5 and 7 kilograms (5.5–16 lb); however, some breeds, such as the Maine Coon, can exceed 11.3 kilograms (24.9 lb). Conversely, very small cats (less than 1.8 kilograms (4.0 lb)) have been reported.[10]

The largest cat ever was officially reported to have weighed in at about 21.297 kilograms (46.952 lb) (46 lb 15.25 oz).[11][12] The smallest cat ever officially recorded weighed around 1.36 kilograms (3 lb).[13]

Cats average about 23–25 centimeters (9–10 in) in height[14] and 46 centimeters (18.1 in) in head/body length (males being larger than females), with tails averaging 30 centimeters (11.8 in) in length.[15]

Skeleton

Cats have 7 cervical vertebrae like almost all mammals, 13 thoracic vertebrae (humans have 12), 7 lumbar vertebrae (humans have 5), 3 sacral vertebrae like most mammals (humans have 5 because of their bipedal posture), and, except for Manx cats, 22 or 23 caudal vertebrae (humans have 3 to 5, fused into an internal coccyx). The extra lumbar and thoracic vertebrae account for the cat's enhanced spinal mobility and flexibility, compared with humans. The caudal vertebrae form the tail, used by the cat as a counterbalance to the body during quick movements. Cats also have free-floating clavicle bones, which allows them to pass their body through any space into which they can fit their heads.[16]

Mouth

Cats have highly specialized teeth for the killing of prey and the tearing of meat. The premolar and first molar together compose the carnassial pair on each side of the mouth, which efficiently functions to shear meat like a pair of scissors. While this is present in canids, it is highly developed in felines. The cat's tongue has sharp spines, or papillae, useful for retaining and ripping flesh from a carcass. These papillae are small backward-facing hooks that contain keratin which also assist in their grooming.

As facilitated by their oral structure, cats use a variety of vocalizations for communication, including meowing, purring, hissing, growling, squeaking, chirping, clicking, and grunting.[7] Their types of body language: position of ears and tail, relaxation of whole body, kneading of paws, all are indicators of mood.

Ears

Thirty-two individual muscles in each ear allow for a manner of directional hearing:[17] a cat can move each ear independently of the other. Because of this mobility, a cat can move its body in one direction and point its ears in another direction. Most cats have straight ears pointing upward. Unlike dogs, flap-eared breeds are extremely rare (Scottish Folds are one such exceptional mutation.) When angry or frightened, a cat will lay back its ears, to accompany the growling or hissing sounds it makes. Cats also turn their ears back when they are playing, or to listen to a sound coming from behind them. The angle of cats' ears is an important clue to their mood.

Legs

Cats, like dogs, are digitigrades. They walk directly on their toes, with the bones of their feet making up the lower part of the visible leg. Cats are capable of walking very precisely, because like all felines they directly register; that is, they place each hind paw (almost) directly in the print of the corresponding forepaw, minimizing noise and visible tracks. This also provides sure footing for their hind paws when they navigate rough terrain.

Claws

Like nearly all members of family Felidae, cats have protractable claws. In their normal, relaxed position the claws are sheathed with the skin and fur around the toe pads. This keeps the claws sharp by preventing wear from contact with the ground and allows the silent stalking of prey. The claws on the forefeet are typically sharper than those on the hind feet.[18] Cats can voluntarily extend their claws on one or more paws. They may extend their claws in hunting or self-defense, climbing, "kneading", or for extra traction on soft surfaces (bedspreads, thick rugs, etc.). It is also possible to make a cooperative cat extend its claws by carefully pressing both the top and bottom of the paw. The curved claws may become entangled in carpet or thick fabric, which may cause injury if the cat is unable to free itself.

Most cats have five claws on their front paws, and four or five on their rear paws. Because of an ancient mutation, however, domestic and feral cats are prone to polydactylyism, (particularly in the east coast of Canada and northeast coast of the United States) and may have six or seven toes. The fifth front claw (the dewclaw) is proximal to the other claws. More proximally, there is a protrusion which appears to be a sixth "finger". This special feature of the front paws, on the inside of the wrists, is the carpal pad, also found on the paws of big cats and dogs. It has no function in normal walking, but is thought to be an anti-skidding device used while jumping.

Skin

Cats possess rather loose skin; this allows them to turn and confront a predator or another cat in a fight, even when it has a grip on them. This is also an advantage for veterinary purposes, as it simplifies injections.[19] In fact, the lives of cats with kidney failure can sometimes be extended for years by the regular injection of large volumes of fluid subcutaneously, which serves as an alternative to dialysis.[20][21]

The particularly loose skin at the back of the neck is known as the scruff, and is the area by which a mother cat grips her kittens to carry them. As a result, cats tend to become quiet and passive when gripped there. This behavior also extends into adulthood, when a male will grab the female by the scruff to immobilize her while he mounts, and to prevent her from running away as the mating process takes place.[22]

This technique can be useful when attempting to treat or move an uncooperative cat. However, since an adult cat is heavier than a kitten, a pet cat should never be carried by the scruff, but should instead have its weight supported at the rump and hind legs, and at the chest and front paws. Often (much like a small child) a cat will lie with its head and front paws over a person's shoulder, and its back legs and rump supported under the person's arm.

Senses

The nose of a cat. The feline sense of smell is extremely sensitive.

Cat senses are attuned for hunting.

Cats' night vision is superior to humans although their vision in daylight is inferior.[23] Cat eyes have a tapetum lucidum and cat eyes that are blue typically lack melanin and hence can show the red-eye effect (see odd-eyed cat).

Humans and cats have a similar range of hearing on the low end of the scale, but cats can hear much higher-pitched sounds, up to 64 kHz, which is 1.6 octaves above the range of a human, and even one octave above the range of a dog.[24]

A domestic cat's sense of smell is about fourteen times as strong as a human's.[25]

Due to a mutation in an early cat ancestor, one of two genes necessary to taste sweetness may have been lost by the cat family.[26]

To aid with navigation and sensation, cats have dozens of movable vibrissae (whiskers) over their body, especially their face.

Metabolism

Two cats curled up together

Cats conserve energy by sleeping more than most animals, especially as they grow older. The daily duration of sleep varies, usually 12–16 hours, with 13–14 being the average. Some cats can sleep as much as 20 hours in a 24-hour period. The term cat nap refers to the cat's ability to fall asleep (lightly) for a brief period and has entered the English lexicon—someone who nods off for a few minutes is said to be "taking a cat nap".

Due to their crepuscular nature, cats are often known to enter a period of increased activity and playfulness during the evening and early morning, dubbed the "evening crazies", "night crazies", "elevenses", or "mad half-hour" by some.[27][28]

The temperament of a cat can vary depending on the breed and socialization. Cats with oriental body types tend to be thinner and more active, while cats that have a cobby body type tend to be heavier and less active.

The normal body temperature of a cat is between 38 and 39 °C (101 and 102.2 °F).[29] A cat is considered febrile (hyperthermic) if it has a temperature of 39.5 °C (103 °F) or greater, or hypothermic if less than 37.5 °C (100 °F). For comparison, humans have a normal temperature of approximately 36.8 °C (98.6 °F). A domestic cat's normal heart rate ranges from 140 to 220 beats per minute, and is largely dependent on how excited the cat is. For a cat at rest, the average heart rate usually is between 150 and 180 bpm, about twice that of a human (average 80 bpm).[30]

Genetics

Blue-eyed cats with white fur have a reputation for having greater incidence of genetic deafness

A 2007 study published in the journal Science asserts that all house cats are descended from a group of self-domesticating desert wildcats Felis silvestris lybica circa 10,000 years ago, in the Near East.[4]

The domesticated cat and its closest wild ancestor are both diploid organisms that possess 38 chromosomes,[31] in which over 200 heritable genetic defects have been identified, many homologous to human inborn errors. Specific metabolic defects have been identified underlying many of these feline diseases. There are several genes responsible for the hair color identified. The combination of them gives different phenotypes.

Features like hair length, lack of tail, or presence of a very short tail (bobtail cat) are also determined by single alleles and modified by polygenes.

The Cat Genome Project, sponsored by the Laboratory of Genomic Diversity at the U.S. National Cancer Institute Frederick Cancer Research and Development Center in Frederick, Maryland, focuses on the development of the cat as an animal model for human hereditary disease, infectious disease, genome evolution, comparative research initiatives within the family Felidae, and forensic potential.

All felines, including the big cats, have a genetic anomaly that may prevent them from tasting sweetness,[26] which is a likely factor for their indifference to or avoidance of fruits, berries, and other sugary foods.

Feeding and diet

A very young cat is being fed with milk

Cats feed on small prey such as insects, birds, and rodents. Feral cats, or house cats who are free-fed, consume about 8 to 16 small meals in a single day. Despite this, adult cats can adapt to being fed once a day.[32] Cats are classified as obligate carnivores, because their physiology is geared toward efficient processing of meat, and lacks efficient processes for digesting plant matter. The cat cannot produce its own taurine (an essential organic acid), and, as it is contained in flesh, the cat must eat flesh to survive (see Taurine and cats). Similar to its teeth, a cat's digestive tract has become specialized over time to suit meat eating, having shortened in length only to those segments of intestine best able to break down proteins and fats from animal flesh.[33] This trait severely limits the cat's ability to properly digest, metabolize, and absorb plant-derived nutrients, as well as certain fatty acids. For example, taurine is scarce in plants but abundant in meats. It is a key amino sulfonic acid for eye health in cats. Taurine deficiency can cause a condition called macular degeneration wherein the cat's retina slowly degenerates, eventually causing irreversible blindness.

A cat eating a House Mouse

Despite the cat's meat-oriented physiology, it is still quite common for a cat to supplement its carnivorous diet with small amounts of grass, leaves, shrubs, houseplants, or other plant matter. One theory suggests this behavior helps cats regurgitate if their digestion is upset; another is that it introduces fiber or trace minerals into the diet. In this context, caution is recommended for cat owners because some houseplants are harmful to cats. For example, the leaves of the Easter Lily can cause permanent and life-threatening kidney damage to cats, and Philodendron are also poisonous to cats. The Cat Fanciers' Association has a full list of plants harmful to cats.[34]

Avocado plant parts are toxic, but the fruit (minus the pit) is an ingredient in AvoDerm cat food.[35] However, the ASPCA has declined to say whether this food is safe or not without knowing the details of how the avocado is processed.[36]

There are several vegetarian or vegan commercially available cat foods supplemented with chemically synthesized taurine and other added nutrients that attempt to address nutritional shortfalls.

Cats can be selective eaters (which may be due in some way to the aforementioned mutation which caused their species to lose sugar-tasting ability). However, cats generally cannot tolerate lack of food for more than 36 hours without risking liver damage.[37]

Cats have a fondness for catnip, which is sensed by their olfactory systems. Many enjoy consuming catnip, and most will often roll in it, paw at it, and occasionally chew on it.

Cats can also develop odd eating habits. Some cats like to eat or chew on other things like plastic, paper, string, wool, or even coal. This condition is called pica and can threaten the cat's health depending on the amount and toxicity of the non-food items eaten.[38] The condition's name comes from the Latin word for magpie, a bird which is reputed to eat almost anything.

Toxic sensitivity

The liver of a cat is less effective at detoxification than those of other animals, including humans and dogs; therefore exposure to many common substances considered safe for households may be dangerous to them.[39][40] In general, the cat's environment should be examined for the presence of such toxins and the problem corrected or alleviated as much as possible; in addition, where sudden or prolonged serious illness without obvious cause is observed, the possibility of toxicity must be considered, and the veterinarian informed of any such substances to which the cat may have had access.

For instance, the common painkiller paracetamol or acetaminophen, sold under brand names such as Tylenol and Panadol, is extremely toxic to cats; because they naturally lack enzymes needed to digest it, even minute portions of doses safe for humans can be fatal[40][41] and any suspected ingestion warrants immediate veterinary attention.[42] Even aspirin, which is sometimes used to treat arthritis in cats, is much more toxic to them than to humans and must be administered cautiously.[40] Similarly, application of minoxidil (Rogaine) to the skin of cats, either accidental or by well-meaning owners attempting to counter loss of fur, has sometimes proved fatal.[43][44]

In addition to such obvious dangers as insecticides and weed killers, other common household substances that should be used with caution in areas where cats may be exposed to them include mothballs and other naphthalene products,[40] as well as phenol-based products often used for cleaning and disinfecting near cats' feeding areas or litter boxes, such as Pine-Sol, Dettol (Lysol), hexachlorophene, etc.[40] which, although they are widely used without problem, have been sometimes seen to be fatal.[45] Ethylene glycol, often used as an automotive antifreeze, is particularly appealing to cats, and as little as a teaspoonful can be fatal.[46] Essential oils are toxic to cats and there have been reported cases of serious illnesses caused by tea tree oil, and tea tree oil-based flea treatments and shampoos.[47][48][49]

Many human foods are somewhat toxic to cats; theobromine in chocolate can cause theobromine poisoning, for instance, although few cats will eat chocolate. Toxicity in cats ingesting relatively large amounts of onions or garlic has also been reported.[40] Even such seemingly safe items as cat food packaged in pull tab tin cans have been statistically linked to hyperthyroidism; although the connection is far from proven, suspicion has fallen on the use of bisphenol A-based plastics, another phenol-based product as discussed above, to seal such cans.[40]

Many houseplants are at least somewhat toxic to many species, cats included[39] and the consumption of such plants by cats is to be avoided.

Behavior

Sociability

Cats can befriend other cats. Here, one cat grooms the other.

For cats, life in close proximity with humans (and other animals kept by humans) amounts to a "symbiotic social adaptation" which has developed over thousands of years. It has been suggested that, ethologically, the human keeper of a cat functions as a sort of surrogate for the cat's mother, and that adult domestic cats live their lives in a kind of extended kittenhood,[50] a form of behavioral neoteny.

Cats may express affection towards their human companions, especially if they imprint on them at a very young age and are treated with consistent affection.

Regardless of the average sociability of any given cat or of cats in general, there are still any number of cats who meet or exceed the negative feline stereotype insofar as being poorly socialized. Older cats have also been reported to sometimes develop aggressiveness towards kittens, which may include biting and scratching; this type of behavior is known as Feline Asocial Aggression.[51]

Cohabitation

One may see natural house cat behavior by observing feral domestic cats, which are social enough to form colonies.[52] Each cat in a colony holds a distinct territory, with sexually active males having the largest territories, and neutered cats having the smallest. Between these territories are neutral areas where cats watch and greet one another without territorial conflicts. Outside these neutral areas, territory holders usually aggressively chase away stranger cats, at first by staring, hissing, and growling, and if that does not work, by short but noisy and violent attacks.

Despite cohabitation in colonies, cats do not have a social survival strategy, or a pack mentality. This mainly means that an individual cat takes care of all basic needs on its own (e.g., finding food, and defending itself), and thus cats are always lone hunters; they do not hunt in groups as dogs or lions do.

Cats frequently tonguebathe themselves (see hygiene). The chemistry of their saliva, expended during their frequent grooming, appears to be a natural deodorant. Thus, a cat's cleanliness would aid in decreasing the chance a prey animal could notice the cat's presence. By contrast, dog odor is an advantage in hunting, for a dog is a pack hunter; part of the pack stations itself upwind, and its odor drives prey towards the rest of the pack stationed downwind. This requires a cooperative effort, which in turn requires communication skills. No such communication skills are required of a lone hunter.

Fighting

Cats' acts of self-defence involve arching their backs, raising their fur, turning sideways, and hissing.

When engaged in feline-to-feline combat for self-defense, territory, reproduction, or dominance, fighting cats make themselves appear more impressive and threatening by raising their fur and arching their backs, thus increasing their apparent size. Cats also behave this way while playing. Attacks usually comprise powerful slaps to the face and body with the forepaws as well as bites, but serious damage is rare; usually the loser runs away with little more than a few scratches to the face, and perhaps the ears. Cats will also throw themselves to the ground in a defensive posture to rake with their powerful hind legs. Normally, serious negative effects will be limited to possible infections of the scratches and bites, though these have been known to sometimes kill cats if untreated. In addition, such fighting is believed to be the primary route of transmission of feline immunodeficiency virus (FIV). Sexually active males will usually be in many fights during their lives, and often have decidedly battered faces with obvious scars and cuts to the ears and nose. Not only males will fight; females will also fight over territory or to defend their kittens.

Play

Two cats play fighting

Domestic cats, especially young kittens, are known for their love of play. This behavior mimics hunting and is important in helping kittens learn to stalk, capture, and kill prey.[53] Many cats cannot resist a dangling piece of string, or a piece of rope drawn randomly and enticingly across the floor. This well known love of string is often depicted in cartoons and photographs, which show kittens or cats playing with balls of yarn. It is probably related to hunting instincts, including the common practice of kittens hunting their mother's and each other's tails. If string is ingested, however, it can become caught in the cat’s stomach or intestines, causing illness, or in extreme cases, death. Due to possible complications caused by ingesting a string, string play is sometimes replaced with a laser pointer's dot, which some cats will chase. While caution is called for, there are no documented cases of feline eye damage from a laser pointer, and the combination of precision needed and low energy involved make it a remote risk. A common compromise is to use the laser pointer to draw the cat to a prepositioned toy so the cat gets a reward at the end of the chase. A regular flashlight with a well-focused light spot has been commonly used in such play for decades, preceding the availability of consumer laser pointers.

Cats will also engage in play fighting, with each other and with human partners. Humans "wrestling" with a supine cat, however, should be wary: if the cat is overstimulated or startled it may decide that the play has turned serious and cease to pull its punches; this can lead to serious scratches and occasionally even bites.

Hunting

A domestic cat presenting a bird to its owner

Much like their big cat relatives, domestic and feral cats are very effective predators.[54] Domestic felines ambush or pounce upon and immobilize vertebrate prey using tactics similar to those of leopards and tigers. Having overpowered such prey, a cat delivers a lethal neck bite with its long canine teeth that either severs the prey's spinal cord with irreversible paralysis to prey, causes fatal bleeding by puncturing the carotid artery or the jugular vein, or asphyxiates the prey by crushing its trachea.

One poorly understood element of cat hunting behavior is the presentation of prey to human owners. Ethologist Paul Leyhausen proposed that cats adopt humans into their social group, and share excess kill with others in the group according to the local pecking order, in which humans are placed at or near the top.[55] However, anthropologist and animal scientist Desmond Morris in his 1986 book Catwatching suggests that when cats bring home mice or birds they have caught, they are teaching their human to hunt, or helping their human as if feeding "an elderly, inept kitten". Another possibility is that presenting the kill might be a relic of a kitten's behavior of demonstrating for its mother's approval that it has developed the necessary skill for hunting. Indoor cats will often retain their hunting instinct and deliver small household items to their owners, such as watches, pens, pencils, and other objects they can carry in their mouths.

Reproduction

When cats mate, the male Tom bites the scruff of the female's neck as she assumes a position conducive to mating.[56]

Cats are seasonally polyestrous, which means they may have many periods of heat over the course of a year. A heat period lasts about 4 to 7 days if the female is bred; if she is not, the heat period lasts longer.

Multiple males will be attracted to a female in heat. The males will fight over her, and the victor wins the right to mate. At first, the female will reject the male, but eventually the female will allow the male to mate. The female will give a loud yowl as the male pulls out of her. After mating, the female will give herself a thorough wash. If a male attempts to breed with her at this point, the female will attack him. Once the female is done grooming, the cycle will repeat.

The male cat's penis has spines which point backwards, a feature shared with other species such as lions. Upon withdrawal of the penis, the spines rake the walls of the female's vagina, which may cause ovulation. Because this does not always occur, females are rarely impregnated by the first male with which they mate. Furthermore, cats are superfecund; that is, a female may mate with more than one male when she is in heat, meaning different kittens in a litter may have different fathers.

A mother cat with kittens a few hours old
A kitten with eyes open for the first time

The gestation period for cats is approximately 63–65 days. The size of a litter averages three to five kittens, with the first litter usually smaller than subsequent litters. Kittens are weaned at between six and seven weeks, and cats normally reach sexual maturity at 5–10 months (females) and to 5–7 months (males).

Cats are ready to go to new homes at about 12 weeks old (the recommended minimum age by Fédération Internationale Féline), or when they are ready to leave their mother. Cats can be surgically sterilized (spayed or castrated) as early as 6–8 weeks to limit unwanted reproduction. This surgery also prevents undesirable sex-related behavior, such as territory marking (spraying urine) in males and yowling (calling) in females. If a cat is neutered after such behavior has been learned, however, then the behavior may persist.

Hygiene

The hooked papillae on a cat tongue acts like a hairbrush to help clean and detangle fur

Cats are known for their fastidious cleanliness. They groom themselves by licking their fur, employing their hooked papillae and saliva. As mentioned, their saliva is a powerful cleaning agent and deodorant. Many cats also enjoy grooming humans or other cats. Sometimes the act of grooming another cat is initiated as an assertion of superior position in the pecking order of a group (dominance grooming).

Some cats occasionally regurgitate hairballs of fur that have collected in their stomachs as a result of their grooming. Longhaired cats are more prone to this than shorthaired cats. Hairballs can be prevented with certain cat foods and remedies that ease elimination of the hair, and regular grooming of the coat with a comb or stiff brush.

Scratching

Cats are naturally driven to periodically hook their front claws into suitable surfaces and pull backwards, in order to clean the claws and remove the worn outer sheath, as well as exercise and stretch their muscles. This scratching behavior seems enjoyable to the cat, and even declawed cats will go through elaborate scratching routines with every evidence of great satisfaction, despite the total lack of results. Some researchers believe this is due to scent glands located in their pads, and that scratching is effectively a part of marking territory.

Fondness for heights

A cat in a tree

Most breeds of cat have a noted fondness for settling in high places, or perching. Animal behaviorists have posited a number of explanations, the most common being that height gives the cat a better observation point, allowing it to survey its territory and become aware of activities of people and other pets in the area. In the wild, a higher place may serve as a concealed site from which to hunt; domestic cats are known to strike prey by pouncing from such a perch as a tree branch, as does a leopard.[57] Height, therefore, can also give cats a sense of security.

During a fall from a high place, a cat can reflexively twist its body and right itself using its acute sense of balance and flexibility.[58] This is known as the cat's "righting reflex". It always rights itself in the same way, provided it has the time to do so, during a fall. The height required for this to occur in most cats (safely) is around 90 cm (3 feet). Cats without a tail also have this ability, since a cat mostly moves its hind legs and relies on conservation of angular momentum to set up for landing, and the tail is in fact little used for this feat.[59]

However, cats' fondness for high spaces can dangerously test the righting reflex. The American Society for the Prevention of Cruelty to Animals warns owners to safeguard the more dangerous perches in their homes, to avoid "high-rise syndrome", where an overconfident cat falls from an extreme height.[60]

Ecology

Habitat

The African Wildcat (Felis silvestris lybica), ancestor of the domestic cat, is believed to have evolved in a desert climate, as evident in the behavior common to both the domestic and wild forms. Wildcats (Felis sylvestris) are native to all continents other than Australia and Antarctica, although feral cats have become apex predators in the Australian Outback where they are menaces to wildlife.[61]

Their feces are usually dry, and cats prefer to bury them in sandy places. Urine is highly concentrated, which allows the cat to retain as much fluid as possible. They are able to remain motionless for long periods, especially when observing prey and preparing to pounce. In North Africa there are still small wildcats that are probably related closely to the ancestors of today's domesticated cat breeds.

Being closely related to desert animals, cats enjoy heat and solar exposure, often sleeping in a sunny area during the heat of the day, as part of a general preference for warm temperatures. Where humans typically start to feel uncomfortable when their skin temperature gets higher than about 44.5 °C (112 °F), by contrast cats do not start to show signs of discomfort until their skin reaches about 52 °C (126 °F).

Overall, cats can easily withstand the heat and cold of a temperate climate, so long as the cold is not for extended periods. Although certain breeds such as the Norwegian Forest Cat and Maine Coon have developed heavier coats of fur than other cats, they have little resistance against moist cold (e.g., fog, rain, and snow) and struggle to maintain their 39 °C (102 °F) body temperature when wet. In direct relation to that fact, most cats dislike immersion in water. One major exception is the Turkish Van breed which has an unusual fondness for water.[62] Abyssinians and Bengals are also reported to be more tolerant of water than most cats.

Impact of hunting

The domestic cat hunts and eats over a thousand species, many of them invertebrates, especially insects; many big cats will eat fewer than a hundred different species. Although theoretically big cats can kill most smaller animals as well, they often do not due to the relatively low nutritional content that these species provide for the effort. An exception is the leopard, which commonly hunts rabbits and many other smaller animals. Even well-fed domestic cats may hunt and kill birds, mice, rats, scorpions, cockroaches, grasshoppers, and other small animals in their environment.

As a consequence of their exceptional hunting ability, cats can be quite destructive to ecosystems in which they are not native, where local species have not had time to adapt to feline introduction. In some cases, cats have contributed to or caused extinctions—for example, see the case of the Stephens Island Wren. Due to their hunting behavior, in many countries feral cats are considered pests. Domestic cats are occasionally also required to have contained cat runs or to be kept inside entirely, as they can be hazardous to locally endangered bird species. For instance, various municipalities in Australia have enacted such legislation. In some localities, owners fit their cat with a bell in order to warn prey of its approach (although some cats may figure out how and when the bell works, thereby learning more careful movements to avoid the ringing).

House cats

Domestication

In 2004, a grave was excavated in Cyprus that contained the skeletons, laid close to one another, of both a human and a cat. The grave is estimated to be 9,500 years old, pushing back the earliest known feline-human association significantly.[5][63][64]

Like some other domesticated animals, cats live in a mutualistic arrangement with humans. It is believed that the benefit of removing rats and mice from humans' food stores outweighed the trouble of extending the protection of a human settlement to a formerly wild animal, almost certainly for humans who had adopted a farming economy. Unlike the dog, which also hunts and kills rodents, the cat does not eat grains, fruits, or vegetables.

In modern rural areas, farms often have dozens of semi-feral cats. Hunting in the barns and the fields, they kill and eat rodents that would otherwise spoil large parts of the grain crop. Many pet cats successfully hunt and kill rabbits, rodents, birds, lizards, frogs, fish, and large insects by instinct, but might not eat their prey.

In modern urban areas, some people find feral and free-roaming pet cats annoying and intrusive. Unaltered cats can engage in persistent nighttime calling (termed caterwauling) and defecation or "marking" of private property. Indoor confinement of pets and trap-neuter-and-return programs for feral cats can help; some people also use cat deterrents to discourage cats from entering their property.

In captivity, indoor cats typically live 14 to 20 years, though the oldest known cat lived to age 36.[65] Domesticated cats tend to live longer if they are not permitted to go outdoors (reducing the risk of injury from fights or accidents and exposure to diseases) and if they are neutered. Some benefits of neutering are that castrated males cannot develop testicular cancer, spayed females cannot develop ovarian cancer, and both have a reduced risk of mammary cancer.[66]

Interaction with humans

Human attitudes toward cats vary widely. Some people keep cats for casual companionship as pets. Cats are also bred and shown as registered pedigree pets, in a hobby known as cat fancy.

Because of their small size, domesticated house cats pose almost no major danger to adult humans—the main hazard is the possibility of infection (e.g., cat scratch disease, or, rarely, rabies) from a cat bite or scratch. Cats can also potentially inflict severe scratches or puncture an eye, though this is quite rare (although dogs have been known to be blinded by cats in fights, where the cat specifically and accurately targeted the eyes of the larger animal).

Allergens

Allergic reactions to cat dander and/or cat saliva inspire one of the most common reasons people cite for disliking cats. Some humans who are allergic to cats—typically manifested by hay fever, asthma, or a skin rash—quickly acclimate themselves to a particular animal and live comfortably in the same house with it, while retaining an allergy to cats in general.[67] However, this should not be depended upon.

Many humans find the rewards of cat companionship outweigh the discomfort and problems associated with these allergens. Some cope with the problem by taking prescription allergy medicine, along with bathing their cats frequently (weekly bathing will eliminate about 90% of the cat dander present in the environment). There are also attempts to breed cats that are less likely to provoke an allergic reaction.

Trainability

Casting call for black cats, Hollywood, 1961

Some owners seek to train their cat in performing tricks commonly exhibited by dogs, such as jumping, though this is rare. Individual cats have been known to learn to manipulate simple mechanisms, like sink faucets, by themselves or after prompting/encouraging. With effort and patience on the part of an owner, the average cat can usually be trained to at least obey simple commands such as "get off the furniture" or "come to dinner". In general though, the seeming intractability of the ordinary house cat to training has long inspired the simile 'like herding cats', as a general expression to describe any situation with a stubborn or uncooperative learner.[68]

Indoor scratching

Cats are naturally driven to periodically hook their front claws into suitable surfaces and pull backwards, in order to clean the claws. Indoor cats benefit from being provided with a scratching post so that they are less likely to use carpet or furniture which they can easily ruin.[69] Commercial scratching posts typically are covered in carpeting or upholstery, but some authorities advise against this practice, as not making it clear to the cat which surfaces are permissible and which are not; they suggest using a plain wooden surface, or reversing the carpeting on the posts so that the rougher texture of the carpet backing is a more attractive alternative to the cat than the floor covering. Scratching posts made of sisal rope or corrugated cardboard are also commonly found. Some indoor cats, however, especially those that were taken as kittens from feral colonies, may not understand the concept of a scratching post, and as a result will ignore it.

Close-up of a cat's claw, with the quick clearly visible

Although scratching can serve cats to keep their claws from growing excessively long, their nails can be trimmed if necessary with a small nail trimmer designed for humans, or a small pair of electrician's diagonal cutting pliers, or a guillotine type cutter specifically designed for animal nail trimming. Care must always be taken to avoid cutting the quick of the claw, analogous to cutting into the tip of a finger and equally painful and bloody. The position of the quick can be easily seen through the translucent nail of a cat with light colored claws but not in cats with dark colored nails, who therefore require carefully trimming of only small amounts from the nails.

Scratching can be reduced and even eliminated by disciplining the cat with a quick spritz from a water bottle when the cat is scratching or by applying a product called Sticky Paws (similar to double-sided tape) to the surface the cat is prone to scratch. Cats are also repelled by citrus scents, and a citrus-scented product may also help stop unwanted furniture destruction. Pet supply stores also sell bitter apple spray, which cats do not like and will generally avoid.

Declawing

Declawing is a surgical procedure, known as onychectomy, to remove the claw and first bone of each digit of a cat's paws. Declawing is most commonly only performed on front feet.

Declawing may be performed to prevent the cat from damaging furniture. Additionally, declawing may be performed on vicious cats, cats that frequently fight with other pets, or cats that are too efficient at predation of animals. In the United States, landlords sometimes require that tenants' cats be declawed.

Declawing is controversial and is uncommon outside of North America.[70] In many countries, it is prohibited by animal cruelty laws. In the US it is condemned by both the Humane Society of the United States and the American Society for the Prevention of Cruelty to Animals[71] and many veterinarians refuse to perform the procedure.

Waste

Indoor cats are usually provided with a litter box containing litter, typically bentonite, but sometimes other absorbent material such as shredded paper or wood chips, or sometimes sand or similar material. This arrangement serves the same purpose as a toilet for humans. It should be cleaned daily and changed often, depending on the number of cats in a household and the type of litter; if it is not kept clean, a cat may be fastidious enough to find other locations in the house for urination or defecation. This may also happen for other reasons; for instance, if a cat becomes constipated and defecation is uncomfortable, it may associate the discomfort with the litter box and avoid it in favor of another location. A litterbox is recommended for indoor-outdoor cats as well.

Toilet-trained house cat.

Daily attention to the litter box also serves as a monitor of the cat's health. Numerous variations on litter and litter box design exist, including some which automatically sift the litter after each use. Bentonite or clumping litter is a variation which absorbs urine into clumps which can be sifted out along with feces, and thus stays cleaner longer with regular sifting, but has sometimes been reported to cause health problems in some cats.[72] Those with toxoplasmosis-infected cats living in habitat areas of sea otters[73] may wish to dispose of droppings in the trash, rather than flushing them down the toilet.[74]

Litterboxes may pose a risk of toxoplasmosis transmission to susceptible pregnant women and immuno-compromised individuals. Most indoor-only cats are not normally exposed to the disease and are not carriers. Transmission risk may be reduced by daily litterbox cleaning by someone other than the susceptible individual.

Some cats can be trained to use the human toilet, eliminating the litter box and its attendant expense, unpleasant odor, and the need to use landfill space for disposal. Training may involve four to six weeks of incremental moves, such as moving and elevating the litter box until it is near the toilet, as well as employing an adapter such as a bowl or small box to suspend the litter above the toilet bowl.[75] Several kits and other aids are marketed to help toilet-train cats. When training is complete, the cat uses the toilet by squatting on the toilet seat over the bowl.

Domesticated varieties

The list of cat breeds is quite large: most cat registries actually recognize between 30 and 40 breeds of cats, and several more are in development, with one or more new breeds being recognized each year on average, having distinct features and heritage. The owners and breeders of show cats compete to see whose animal bears the closest resemblance to the "ideal" definition and standard of the breed (see selective breeding). Because of common crossbreeding in populated areas, many cats are simply identified as belonging to the homogeneous breeds of domestic longhair and domestic shorthair, depending on their type of fur. In the United Kingdom and Australia, non-purebred cats are referred in slang as moggies (derived from "Maggie", short for Margaret, reputed to have been a common name for cows and calves in 18th century England and latter applied to housecats during the Victorian era).[76] In the United States, a non-purebred cat is sometimes referred to in slang as a barn or alley cat, even if it is not a stray. Cats come in a variety of colors and patterns. These are physical properties and should not be confused with a breed of cat. Some original cat breeds that have a distinct phenotype that is the main type occurring naturally as the dominant domesticated cat type in their region of origin are sometimes considered as subspecies and also have received names as such in nomenclature, although this is not supported by feline biologists. Some of these cat breeds are:

  • F. catus anura - the Manx
  • F. catus siamensis - the Siamese
  • F. catus cartusenensis - the Chartreux
  • F. catus angorensis - the Turkish Angora
Cat with a van pattern

Coat patterns

Cat coat genetics can produce a variety of coat patterns. Some of the most common are:

Bicolor, Tuxedo and Van 
This pattern varies between the tuxedo cat which is mostly black with a white chest, and possibly markings on the face and paws/legs, all the way to the Van pattern (so named after the Lake Van area in Turkey, which gave rise to the Turkish Van breed), where the only colored parts of the cat are the tail (usually including the base of the tail proper), and the top of the head (often including the ears). There are several other terms for amounts of white between these two extremes, such as Harlequin or jellicle cat. Bicolor cats can have as their primary (non-white) color black, red, any dilution thereof, and tortoiseshell (see below for definition).
Mackerel tabby cat, showing the characteristic "M" on its forehead.
Tabby cat 
Striped, with a variety of patterns. The classic "blotched" tabby (or "marbled") pattern is the most common and consists of butterflies and bullseyes. The "mackerel" or "striped" tabby is a series of vertical stripes down the cat's side (resembling the fish). This pattern broken into spots is referred to as a "spotted" tabby. Finally, the tabby markings may look like a series of ticks on the fur, thus the "ticked" tabby, which is almost exclusively associated with the Abyssinian breed of cats. The worldwide evolution of the cat means that certain types of tabby are associated with certain countries; for instance, blotched tabbies are quite rare outside NW Europe, where they are the most common type.
Female tortoiseshell-and-white cat
Tortoiseshell and Calico
This cat is also known as a Calimanco cat or Clouded Tiger cat, and by the nickname "tortie." In the cat fancy, a tortoiseshell cat is randomly patched over with red (or its dilute form, cream) and black (or its dilute blue) mottled throughout the coat. Additionally, the cat may have white spots in its fur, which make it a "tortoiseshell and white" cat or, if there is a significant amount of white in the fur and the red and black colors form a patchwork rather than a mottled aspect, the cat will be called a "calico." All calicos are tortoiseshell (as they carry both black and red), but not all tortoiseshells are calicos (which requires a significant amount of white in the fur and patching rather than mottling of the colors). The calico is also sometimes called a "tricolor cat." The Japanese refer to this pattern as mi-ke (meaning "triple fur"), while the Dutch call these cats lapjeskat (meaning "patches cat"). A true tricolor must consist of three colors: a reddish color, dark or light; white; and one other color, typically a brown, black, or blue.[77] Both tortoiseshell and calico cats are typically female because the coat pattern is the result of differential X chromosome inactivation in females (which, as with all normal female mammals, have two X chromosomes). Conversely, cats where the overall color is ginger (orange) are commonly male (roughly in a 3:1 ratio). In a litter sired by a ginger tom, the females will be tortoiseshell or ginger. Male tortoiseshells can occur as a result of chromosomal abnormalities (often linked to sterility) or by a phenomenon known as mosaicism, where two early stage embryos are merged into a single kitten.
Siamese cat, classical colorpoint pattern
Colorpoint
The colorpoint pattern is most commonly associated with Siamese cats, but may also appear in any domesticated cat. A colorpointed cat has dark colors on the face, ears, feet, and tail, with a lighter version of the same color on the rest of the body, and possibly some white. The exact name of the colorpoint pattern depends on the actual color, so there are seal points (dark brown), chocolate points (warm lighter brown), blue points (dark gray), lilac or frost points (silvery gray-pink), red or flame points (orange), and tortie (tortoiseshell mottling) points, among others. This pattern is the result of a temperature sensitive mutation in one of the enzymes in the metabolic pathway from tyrosine to pigment, such as melanin; thus, little or no pigment is produced except in the extremities or "points," where the skin is slightly cooler. For this reason, colorpointed cats tend to darken with age as bodily temperature drops; also, the fur over a significant injury may sometimes darken or lighten as a result of temperature change.
The tyrosine pathway also produces neurotransmitters, thus mutations in the early parts of that pathway may affect not only pigment, but also neurological development. This results in a higher frequency of cross-eyes among colorpointed cats, as well as the high frequency of cross-eyes in white tigers.
White cats
True albinism (a mutation of the tyrosinase gene) is quite rare in cats. Much more common is the appearance of white coat color due to a lack of melanocytes in the skin. A higher frequency of deafness in white cats is due to a reduction in the population and survival of melanoblast stem cells, which in addition to creating pigment producing cells, develop into a variety of neurological cell types. White cats with one or two blue eyes have a particularly high likelihood of being deaf.
Smoke cats
The bottom eighth of each hair is white or creamy-white, with the rest of the hair being a solid color. Genetically this color is a non-agouti cat with the dominant inhibitor gene; a non-agouti version of the silver tabby. Smoke cats will look solid colored until they move, when the white undercoat becomes apparent. It is mostly found in pedigreed cats (especially longhair breeds) but also present in some domestic longhaired cats.

Body types

Cats can also come in several body types, ranging between two extremes:

Oriental
Not a specific breed, but any cat with an elongated slender build, almond-shaped eyes, long nose, large ears (the Siamese and Oriental Shorthair breeds are examples of this).
Foreign
less slender than the oriental type, but nevertheless a cat with a slight build and generally athletic look. Typical example breeds would be the Abyssinian cat and the Turkish Angora. Some people consider the foreign and oriental body types as being the same, however.
Semi-Foreign
More or less the middle range of body conformation types, this type of cat is less slender without being stocky. Example breeds would be the Devon Rex and the Egyptian Mau.
Semi-Cobby
these cats look more rounded without looking too stocky. Example breeds would be the American Shorthair and British Shorthair.
Cobby
Any cat with a short, muscular, compact build, roundish eyes, short nose, and small ears. Persian cats and Exotic cats are two prime examples of such a body type.

Feral cats

Feral farm cat showing effects of a rough life

Feral cats may live alone, but most are found in large groups called feral colonies with communal nurseries, depending on resource availability. Most abandoned cats probably have little alternative to joining a feral colony. Some feral cat colonies are found in large cities such as around the Colosseum and Forum Romanum in Rome. The Roman cats are not truly feral because they are partly fed and vetted by the local authority. Because cats are adaptable, those in residential areas know that if they are friendly to humans they need not worry about food or shelter. Some urban "stray" cats have many houses/humans to support them.

Although cats are adaptable, feral felines are unable to thrive in extreme cold and heat, and with a very high protein requirement, few find adequate nutrition on their own in cities. They are often killed by dogs, coyotes, and automobiles. However, there are thousands of volunteers and organizations that trap these unadoptable feral felines, neutering them, immunize the cats against rabies and feline leukemia, and treat them with long-lasting flea products. Before release back into their feral colonies, the attending veterinarian often nips the tip off one ear to mark the feral as neutered and inoculated, since these cats will more than likely find themselves trapped again. Volunteers continue to feed and give care to these cats throughout their lives, and not only is their lifespan greatly increased, but behavior and nuisance problems, due to competition for food, are also greatly reduced.

Environmental effects

Trapped feral cat

Feral cats are thought to be a major predator of Hawaiian coastal and forest habitats, and are one species among many responsible for the decline of endemic forest bird species as well as seabirds like the Wedge-tailed Shearwater.[78] In one study of 56 cats' feces, the remains of 44 birds were found, 40 of which were endemic species.[79]

In the Southern Hemisphere there are many landmasses including Australia where cat species have never been native, and other placental mammalian predators were rare or absent. Native species there, for example, the Kakapo, tend to be more ecologically vulnerable and behaviorally "naive" to predation by feral cats. Feral cats have had serious effects on these wildlife species and have played a leading role in the endangerment and extinction of many of them. In Australia a large quantity of native birds, lizards and small marsupials are taken every year by feral cats, and feral cats have played a role in driving some small marsupial species to extinction. Some organizations in Australia are now making the effort to create fenced islands of habitat for endangered species that are free of feral cats and foxes.[80]

Ethical and humane concerns over feral cats

The environmental impact of feral cat programs and of indoor/outdoor cats is a subject of debate. Part of this stems from humane concern for the cats, and part stems from concerns about cat predation on endangered species. The amount of ecological damage done by indoor/outdoor cats depends on local conditions. As suggested above, the most severe effect occurs to island ecologies. Environmental concerns may be minimal in most of the UK where cats are an established species and few to none of the local prey species are endangered. Pet owners can contact veterinarians, ecological organizations, and universities for opinions about whether local conditions are suitable for outdoor cats. Additional concerns include potential dangers from larger predators and infectious diseases. Coyotes kill large numbers of housecats in the Southwestern United States, even in urban zones. FELV (feline leukemia), FIV (feline immunodeficiency virus), or rabies may be present in the area. If faced with conflicting evidence, the safe choice is to keep a cat indoors.

Cats present a risk of overpopulation, as well. According to the Humane Society of the United States, 3–4 million cats and dogs are euthanized each year in the United States and many more are confined to cages in shelters because there are significantly more animals being born than there are homes. Neutering pets helps keep the overpopulation down. A study in 1992 found that in the USA, 12,893 (29.4%) of pets, 26.9% of dogs and 32.6% of cats were sterilized.[81] Local humane societies, SPCAs, and other animal protection organizations urge people to neuter their pets and to adopt from shelters instead of purchasing elsewhere.

Etymology and taxonomic history

Scientific classification

The domestic cat was first classified as Felis catus by Carolus Linnaeus in the tenth edition of his Systema Naturae of 1758.[2][82] However, some contemporary studies have revealed evidence that domestic cats may be conspecific with (belong to the same species as) the Wildcat,[82] classified as Felis silvestris by Schreber in 1777.[83] This has resulted in mixed usage of the terms. The domestic cat is sometimes considered to be a subspecies, F. s. catus, of the species F. silvestris.[4] Wildcats have also been referred to as various subspecies of F. catus,[83] but in 2003, Opinion 2027 of the ICZN fixed the name for Wildcats as F. silvestris.[84] The predominant usage for the domestic cat remains to be F. catus, treating it as a separate species and following the convention of using the earliest (the senior) synonym proposed.

Johann Christian Polycarp Erxleben classified the domesticated cat as Felis domesticus in his Anfangsgründe der Naturlehre and Systema regni animalis of 1777. This name, and its variants Felis catus domesticus and Felis silvestris domesticus, are often seen, but they are not valid scientific names under the rules of the International Code of Zoological Nomenclature.

Nomenclature

A group of cats is referred to as a "clowder", a male cat is called a "tom" (or a "gib", if neutered), and a female is called a "molly" or "queen". The male progenitor of a cat, especially a pedigreed cat, is its "sire", and its female progenitor is its "dam". An immature cat is called a "kitten" (which is also an alternative name for young rats, rabbits, hedgehogs, beavers, squirrels and skunks). In medieval Britain, the word kitten was interchangeable with the word catling. A cat whose ancestry is formally registered is called a pedigreed cat, purebred cat, or a show cat (although not all show cats are pedigreed or purebred). In strict terms, a purebred cat is one whose ancestry contains only individuals of the same breed. A pedigreed cat is one whose ancestry is recorded, but may have ancestors of different breeds (almost exclusively new breeds; cat registries are very strict about which breeds can be mated together). Cats of unrecorded mixed ancestry are referred to as domestic longhairs and domestic shorthairs or commonly as random-bred, moggies, mongrels, mutt-cats or alley cats. The ratio of pedigree/purebred cats to random-bred cats varies from country to country. However, generally speaking, purebreds are less than ten percent of the total Feline population.[85]

Etymology

The word cat derives from Old English catt, which belongs to a group of related words in European languages, including Welsh cath, Spanish gato, Basque katu, Byzantine Greek kátia, Old Irish cat, German Katze, and Old Church Slavonic kotka. The ultimate source of all these terms is Late Latin catus, cattus, catta "domestic cat", as opposed to feles "European wildcat". It is unclear whether the Greek or the Latin came first, but they were undoubtedly borrowed from an Afro-Asiatic language akin to Nubian kadís and Berber kaddîska, both meaning "wildcat".[86] This term was either cognate with or borrowed from Late Egyptian čaus "jungle cat, African wildcat" (later giving Coptic šau "tomcat"),[87] itself from earlier Egyptian tešau "female cat"[88] (vs. miew "tomcat").[89]

The term puss (as in pussycat) may come from Dutch poes or from Low German Puuskatte, dialectal Swedish kattepus, or Norwegian pus, pusekatt, all of which primarily denote a woman and, by extension, a female cat.[90]

History and mythology

Egyptian sculpture at the Louvre

Cats have been kept by humans since at least ancient Egypt, where Bast in cat form was goddess of the home, the domesticated cat, protector of the fields and home from vermin infestations, and sometimes took on the warlike aspect of a lioness. The first domesticated cats may have saved early Egyptians from many rodent infestations and likewise, Bast developed from the adoration for her feline companions. She was the daughter of the sun god Ra and played significant role in Ancient Egyptian religion. It has been speculated that cats resident in Kenya's Islands in the Lamu Archipelago may be the last living direct descendants of the cats of ancient Egypt.[91]

Freya and her cats

Several ancient religions believed that cats are exalted souls, companions or guides for humans, that they are all-knowing but are mute so they cannot influence decisions made by humans. In Japan, the Maneki Neko is a cat that is a symbol of "good fortune". Although there are no sacred species in Islam, it is said by some writers that Muhammad had a favorite cat, Muezza.[92] It is said he loved cats so much that "he would do without his cloak rather than disturb one that was sleeping on it".[93]

Freyja—the goddess of love, beauty, and fertility in Norse mythology—is depicted as riding a chariot drawn by cats.

There are also negative superstitions about cats in many cultures. An example would be the belief that a black cat "crossing your path" leads to bad luck, or that cats are witches' familiars used to augment a witch's powers and skills. This belief led to the widespread extermination of cats in Europe in medieval times. Killing the cats aggravated epidemics of the Black Plague in places where there were not enough cats left to keep rat populations down. The plague was spread by fleas carried by infected rats.

An exaggerated fear of cats is known as ailurophobia.

Nine lives

According to a myth in many cultures, cats have nine (or sometimes seven) lives. The myth is attributed to the natural suppleness and swiftness cats exhibit to escape life-threatening situations.[94] Also lending credence to this myth is that falling cats often land on their feet because of an inbuilt automatic twisting reaction and are able to twist their bodies around to land feet first, though they can still be injured or killed by a high fall.[95]

Cats in Pop Culture

As their role as (extremely) popular pets, cats have had a strong role in pop culture.

Famous animated cats include Felix the Cat and Sylvester from Looney Tunes.

Cats and kittens are an icon in Web humor, such as the Lolcat from 4chan

 

Dogs (name is Buddy. Breed is a St.Bernard)

his article is about the domestic dog. For other uses, see Dog (disambiguation).
Domestic dog
Fossil range: Late Pleistocene – Recent
A Labrador Retriever
Conservation status
Domesticated
Scientific classification
Kingdom: Animalia
Subkingdom: Eumetazoa
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Subclass: Theria
Order: Carnivora
Suborder: Caniformia
Family: Canidae
Subfamily: Caninae
Tribe: Canini[1]
Genus: Canis
Species: C. lupus
Subspecies: C. l. familiaris
Trinomial name
Canis lupus familiaris
Synonyms
  • Canis familiaris
  • Canis familiaris domesticus

The dog (Canis lupus familiaris,[2] pronounced /ˈkeɪ.nis ˈluːpəs fʌˈmɪliɛəris/) is a domesticated subspecies of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The domestic dog has been one of the most widely kept working and companion animals in human history.

The domestication of the gray wolf took place in a handful of events roughly 15,000 years ago in central Asia.[citation needed] The dog quickly became ubiquitous across culture in all parts of the world, and was extremely valuable to early human settlements. For instance, it is believed that the successful emigration across the Bering Strait might not have been possible without sled dogs.[3] As a result of the domestication process, the dog developed a sophisticated intelligence that includes unparalleled social cognition and a simple theory of mind[citation needed] that is important to their interaction with humans. These social skills have helped the dog to perform in myriad roles, such as hunting, herding, protection, and, more recently, assisting handicapped individuals. Currently, there are estimated to be 400 million dogs in the world.[4]

Over the 15,000 year span that the dog had been domesticated, it diverged into only a handful of landraces, groups of similar animals whose morphology and behavior have been shaped by environmental factors and functional roles. As the modern understanding of genetics developed, humans began to intentionally breed dogs for a wide range of specific traits. Through this process, the dog has developed into hundreds of varied breeds, and shows more behavioral and morphological variation than any other land mammal.[5] For example, height measured to the withers ranges from a few inches in the Chihuahua to a few feet in the Irish Wolfhound; color varies from white through grays (usually called "blue'") to black, and browns from light (tan) to dark ("red" or "chocolate") in a wide variation of patterns; coats can be short or long, coarse-haired to wool-like, straight, curly, or smooth.[6] It is common for most breeds to shed this coat, but non-shedding breeds are also popular.

Contents

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Etymology and related terminology

Dog is the common use term that refers to members of the subspecies Canis lupus familiaris. The term is sometimes used to refer to a wider range of species: it can be used to refer to any mammal belonging to the family Canidae, which includes wolves, foxes, jackals, and coyotes; it can be used to refer to the subfamily of Caninae, or the genus Canis, also often called the "true dogs".[7] Some members of the family have "dog" in their common names, such as the raccoon dog and the African wild dog. A few animals have "dog" in their common names but are not canids, such as the prairie dog and the dog fish.

The English word "dog" can be traced back to the Old English docga, a "powerful breed of canine".[8] The term may derive from Proto-Germanic *dukkōn, represented in Old English finger-docce ("finger-muscle").[9] Due to the linguistically archaic structure of the word, the term dog may ultimately derive from the earliest layer of Proto-Indo-European vocabulary, reflecting the role of the dog as the earliest domesticated animal.[10]

The English word hound, which refers to a specific breed group in English, means "dog" in general in other Germanic languages - it is cognate to German hund, Dutch hond, common Scandinavian hund, and Icelandic hundur. Hound itself is derived from the Proto-Indo-European *kwon-, which is also the direct root of the Greek κύων (kuōn) and the indirect root of the Latin canis through the variant form *kani-.[11]

In breeding circles, a male canine is referred to as a dog, while a female is called a bitch. A group of offspring is a litter. The father of a litter is called the sire, and the mother is called the dam. Offspring are generally called pups or puppies until they are about a year old. The process of birth is whelping.[12]

Taxonomy and evolution

In Jan van Eyck's famous Arnolfini Portrait (1434), care was taken to include the couple's little pet dog.

The domestic dog was originally classified as Canis familiaris and Canis familiarus domesticus by Carolus Linnaeus in 1758,[13][14] and is currently classified as Canis lupus familiaris, a subspecies of the gray wolf Canis lupus, by the Smithsonian Institution and the American Society of Mammalogists. Overwhelming evidence from behavior, vocalizations, morphology, and molecular biology led to the contemporary scientific understanding that a single species, the gray wolf, is the common ancestor for all breeds of domestic dogs,[3][15] however the timeframe and mechanisms by which dogs diverged are controversial.[3]

The current consensus among biologists and archaeologists is that no one can be sure when dogs were domesticated.[3][16] There is conclusive evidence that dogs genetically diverged from their wolf ancestors at least 15,000 years ago[17][18][19] but some believe domestication to have occurred earlier.[3] The bulk of the scientific evidence for the evolution of the domestic dog stems from archaeological findings and mitochondrial DNA studies. The divergence date of roughly 15000 years ago is based in part on archaeological evidence that demonstrates that the domestication of dogs occurred more than 15,000 years ago,[3][16] and some genetic evidence indicates that the domestication of dogs from their wolf ancestors began in the late Upper Paleolithic close to the Pleistocene/Holocene boundary, between 17,000 and 14,000 years ago.[20] But there is a wide range of other, contradictory findings that make this issue controversial.

Archaeological evidence plays a large role in this debate. In 2008, a team of international scientists released findings from an excavation at Goyet Cave in Belgium declaring that a large, toothy canine existed 31,700 years ago and ate a diet of horse, musk ox and reindeer.[21] The morphology of the skeleton and the context in which it was found led researchers to hypothesize that this canine was an ancient domesticated dog. Prior to this Belgium discovery, the earliest dog fossils were two large skulls from Russia and a mandible from Germany, that dated from roughly 14,000 years ago.[3][19] Remains of smaller dogs from Natufian cave deposits in the Middle East have been dated to around 10,000 to 12,000 years ago.[19] There is a great deal of archaeological evidence for dogs throughout Europe and Asia around this period and through the next two thousand years (roughly 8,000 to 10,000 years ago), with fossils uncovered in Germany, the French Alps, and Iraq, and cave paintings in Turkey.[3]

This ancient mosaic, likely Roman, shows a large dog with a collar hunting a lion.

Thus, the archaeological evidence suggests that the latest dogs could have diverged from wolves was roughly 15000 years ago, although it is possible that they diverged much earlier.[3]

DNA studies have provided a wider range of possible divergence dates, from 15,000 to 40,000 years ago,[19] to as much as 100,000 to 140,000 years ago.[22] This evidence depends on a number of assumptions that may be violated.[3] Genetic studies are based on comparisons of genetic diversity between species, and depend on a calibration date. Many estimates of divergence dates from DNA evidence use an estimated wolf-coyote divergence date (roughly 1 million years ago) as a calibration. If this estimate is incorrect, and the actual wolf-coyote divergence is closer to 750,000 or 2 million years ago, then the DNA evidence that supports specific dog-wolf divergence dates would be interpreted very differently. Furthermore, it is believed that the genetic diversity of wolves has been in decline for the last 200 years, and that the genetic diversity of dogs has been reduced by selective breeding. This could significantly bias DNA analyses to support an earlier divergence date. The genetic evidence for the domestication event occurring in East Asia is also subject to violations of assumptions. These conclusions are based on the location of maximal genetic divergence, and assume that hybridization does not occur, and that breeds remain geographically localized. Although these assumptions hold for many species, there is good reason to believe that they do not hold for canines.[3]

Genetic analyses indicate all dogs are likely descended from a handful of domestication events with a small number of founding females,[3][20] although there is evidence that domesticated dogs interbred with local populations of wild wolves on several occasions.[19] Data suggests that dogs first diverged from wolves in East Asia, and that these domesticated dogs then quickly migrated throughout the world, reaching the North American continent around 8000 B.C.[19] The oldest groups of dogs, which show the greatest genetic variability and are the most similar to their wolf ancestors, are primarily Asian and African breeds, including the Basenji, Lhasa Apso, and Siberian Husky.[23] Some breeds that were thought to be very old, such as the Pharaoh Hound, Ibizan Hound, and Norwegian Elkhound, are now known to have been created more recently.[23]

There is a great deal of controversy surrounding the evolutionary framework for the domestication of dogs.[3] Although it is widely claimed that "man domesticated the wolf,"[24] man may not have taken such a proactive role in the process.[3] The nature of the interaction between man and wolf that led to domestication is unknown and controversial. At least three early species of the Homo genus began spreading out of Africa roughly 400,000 years ago, and thus lived for a considerable period in contact with canine species. Despite this, there is no evidence of any adaptation of canine species to the presence of the close relatives of modern man. If dogs were domesticated, as believed, roughly 15,000 years ago, the event (or events) would have coincided with a large expansion in human territory and the development of agriculture. This has led some biologists to suggest that one of the forces that led to the domestication of dogs was a shift in human lifestyle in the form of established human settlements. Permanent settlements would have coincided with a greater amount of disposable food and would have created a barrier between wild and anthropogenic canine populations.[3]

Biology

Domestic dogs have been selectively bred for millennia for various behaviors, sensory capabilities, and physical attributes.[2] Modern dog breeds show more variation in size, appearance, and behavior than any other domestic animal. Nevertheless, their morphology is based on that of their wild ancestors, gray wolves.[2] Dogs are predators and scavengers, and like many other predatory mammals, the dog has powerful muscles, fused wrist bones, a cardiovascular system that supports both sprinting and endurance, and teeth for catching and tearing. Dogs are highly variable in height and weight. The smallest known adult dog was a Yorkshire Terrier, that stood only 6.3 cm (2.5 in) at the shoulder, 9.5 cm (3.75 in) in length along the head-and-body, and weighed only 113 grams (4 ounces). The largest 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.[25] The tallest dog is a Great Dane that stands 106.7 cm (42.2 in) at the shoulder.[26]

Senses

Sight

A Greyhound, one of many breeds of sighthound.

Acuity

The dog's visual system has evolved to aid proficient hunting.[27] While a dog's visual acuity is poor (that of a poodle's has been estimated to translate to a Snellen rating of 20/75[27]), their visual discrimination for moving objects is very high; dogs have been shown to be able to discriminate between humans (e;g. identifying their owner) from distances up to a mile.[27] As crepuscular hunters, dogs often rely on their vision in low light situations: they have very large pupils, a high density of rods in the fovea, an increased flicker rate, and a tapetum lucidum.[27] The tapetum is a reflective surface behind the retina that reflects light back to give the photoreceptors a second chance to catch the photons.

Color Perception

Like most mammals, dogs are dichromats and have color vision equivalent to red-green color blindness in humans (deuteranopia).[27][28][29][30]

Field of Vision

The eyes of different breeds of dogs have different shapes, dimensions, and retina configurations.[31] Many long-nosed breeds have a "visual streak" — a wide foveal region that runs across the width of the retina and gives them a very wide field of excellent vision. Some long-muzzled breeds, particularly the sighthounds, have a field of vision up to 270° (compared to 180° for humans). Short-nosed breeds, on the other hand, 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 broad-headed breeds with short noses have a field of vision similar to that of humans.[28][29] Most breeds have good vision, but some show a genetic predisposition for myopia — such as Rottweilers, where one out of every two has been found to be myopic.[27]

Hearing

The frequency range of dog hearing is approximately 40 Hz to 60,000 Hz,[32] which means that dogs can detect sounds outside both ends of the human auditory spectrum.[29][32][33] Additionally, dogs have ear mobility which allows them to rapidly pinpoint the exact location of a sound.[34] Eighteen or more muscles can tilt, rotate, raise, or lower a dog's ear. A dog can identify a sound's location much faster than a human can, as well as hear sounds at four times the distance.[34]

Smell

The highly sensitive nose of a dog.

While the human brain is dominated by a large visual cortex, the dog brain is dominated by an olfactory cortex.[27] The olfactory bulb in dogs is roughly forty times bigger than the olfactory bulb in humans, relative to total brain size, with 125 to 220 million smell-sensitive receptors.[27] The bloodhound exceeds this standard with nearly 300 million receptors.[27] Dogs can discriminate odors at concentrations nearly 100 million times lower than humans can.[35] The wet nose is essential for determining the direction of the air current containing the smell. Cold receptors in the skin are sensitive to the cooling of the skin by evaporation of the moisture by air currents.[36]

Physical characteristics

Coat

The coats of domestic dogs are either "double", made up of a coarse topcoat and a soft undercoat, like a wolf, or "single", with the topcoat only. Dogs with double coats tend to originate in colder climates.

Domestic dogs often display the remnants of countershading, a common natural camouflage pattern. The general theory of countershading is that an animal that is lit from above will appear lighter on its upper half and darker on its lower half, where it will usually be in its own shade.[37][38] This is a pattern that predators can learn to watch for. A countershaded animal will have dark coloring on its upper surfaces and light coloring below,[37] which reduces its general visibility. Thus many breeds will have an occasional "blaze", stripe, or "star" of white fur on their chest or underside.[38]

Tail

There are many different shapes for dog tails: straight, straight up, sickle, curled, or cork-screw. In some breeds, the tail is traditionally docked to avoid injuries (especially for hunting dogs).[39] In some breeds, puppies can be born with a short tail or no tail at all.[40] This occurs more frequently in those breeds that are frequently docked and thus have no breed standard regarding the tail.

Types and breeds

Cavalier King Charles Spaniels demonstrate with-breed variation.

While all dogs are genetically very similar,[19] natural selection and selective breeding have reinforced certain characteristics in certain populations of dogs, giving rise to dog types and dog breeds. Dog types are broad categories based on function, genetics, or characteristics.[41] Dog breeds are groups of animals that possess a set of inherited characteristics that distinguishes them from other animals within the same species. Modern dog breeds are non-scientific classifications of dogs kept by modern kennel clubs. Purebred dogs of one breed are genetically distinguishable from purebred dogs of other breeds,[23] but the means by which kennel clubs classify dogs is unsystematic. Systematic analyses of the dog genome has revealed only four major types of dogs that can be said to be statistically distinct.[23] These include the "old world dogs" (e.g., Malamute and Shar-Pei), "Mastiff"-type (e.g., Labrador Retriever), "herding"-type (e.g., St. Bernard), and "all others" (also called "modern"- or "hunting"-type).[23][42]

Health

Dogs are susceptible to various diseases, ailments, and poisons, some of which can affect humans. To defend against many common diseases, dogs are often vaccinated.

First generation hybrids such as this terrier mix often are healthier than either parent due to the genetic phenomenon of heterosis or "hybrid vigor".

Some breeds of dogs are prone to certain genetic ailments such as elbow or hip dysplasia, blindness, deafness, pulmonic stenosis, cleft palate, and trick knees. Two serious medical conditions particularly affecting dogs are pyometra, affecting unspayed females of all types and ages, and bloat, which affects the larger breeds or deep-chested dogs. Both of these are acute conditions, and can kill rapidly. Dogs are also susceptible to parasites such as fleas, ticks, and mites, as well as hookworms, tapeworms, roundworms, and heartworms.

Dogs are also vulnerable to some of the same health conditions as humans, including diabetes, dental and heart disease, epilepsy, cancer, hypothyroidism, and arthritis.[citation needed]

Mortality

The typical lifespan of dogs varies widely among breeds, but for most the median longevity, the age at which half the dogs in a population have died and half are still alive, ranges from 10 to 13 years.[43][44][45][46] Individual dogs may live well beyond the median of their breed.

The breed with the shortest lifespan (among breeds for which there is a questionnaire survey with a reasonable sample size) is the Dogue de Bordeaux, with a median longevity of about 5.2 years, but several breeds, including Miniature Bull Terriers, Bloodhounds, and Irish Wolfhounds are nearly as short-lived, with median longevities of 6 to 7 years.[46]

The longest-lived breeds, including Toy Poodles, Border Terriers, and Tibetan Spaniels, have median longevities of 14 to 15 years.[46] The median longevity of mixed breed dogs, taken as an average of all sizes, is one or more years longer than that of purebred dogs when all breeds are averaged.[44][45][46][47] The dog widely reported to be the longest-lived is "Bluey," who died in 1939 and was claimed to be 29.5 years old at the time of his death; however, the Bluey record is anecdotal and unverified.[48] The longest verified records are of dogs living for 24 years.[48]

Predation

Although wild dogs, like wolves, are apex predators, they can be killed in territory disputes with wild animals.[49] Furthermore, in areas where both dogs and other large predators live, dogs can be a major food source for big cats or canines. Reports from Croatia indicate that dogs are killed more frequently than sheep. Wolves in Russia apparently limit feral dog populations. In Wisconsin, more compensation has been paid for dog losses than livestock.[49] Some wolf pairs have been reported to prey on dogs by having one wolf lure the dog out into heavy brush where the second animal waits in ambush.[50] In some instances, wolves have displayed an uncharacteristic fearlessness of humans and buildings when attacking dogs, to the extent that they have to be beaten off or killed.[51] Coyotes and big cats have also been known to attack dogs. Leopards in particular are known to have a predilection for dogs, and have been recorded to kill and consume them regardless of the dog's size or ferocity.[52] Tigers in Manchuria, Indochina, Indonesia, and Malaysia, are reputed to kill dogs with the same vigor as leopards.[53] Striped Hyenas are major predators of village dogs in Turkmenistan, India, and the Caucasus.[54]

Diet

Golden Retriever eating a pig's foot.

Despite its descent from wolves, the domestic dog is an omnivore,[2] though it is classified in the order Carnivora. Unlike an obligate carnivore, such as a member of the cat family with its shorter small intestine, a dog is neither dependent on meat-specific protein nor a very high level of protein in order to fulfill its basic dietary requirements. Dogs are able to healthily digest a variety of foods, including vegetables and grains, and can consume a large proportion of these in their diet. In the wild, canines often eat available plants and fruits.[2]

Reproduction

Two dogs copulating on a beach

In domestic dogs, sexual maturity begins to happen around age six to twelve months for both males and females,[2][55] although this can be delayed until up to two years old for some large breeds. This is the time at which female dogs will have their first estrous cycle. They will experience subsequent estrous cycles biannually, during which the body prepares for pregnancy. At the peak of the cycle, females will come into estrus, being mentally and physically receptive to copulation.[2] Because the ova survive and are capable of being fertilized for a week after ovulation, it is possible for a female to mate with more than one male.[2]

Adolescence for most domestic dogs is around 12 to 15 months, beyond which they are for the most part more adult than puppy.[citation needed] Domestication has selectively bred for higher libido and earlier and more frequent breeding cycles in dogs than in their wild ancestors, and dogs remain reproductively active until old age.[citation needed]

Dogs bear their litters roughly 56 to 72 days after fertilization,[2][56] with an average of 63 days, although the length of gestation can vary. An average litter consists of about six puppies,[57] though this number may vary widely based on the breed of dog. Toy dogs generally produce from one to four puppies in each litter, while much larger breeds may average as many as twelve.

Some dog breeds have acquired traits through selective breeding that interfere with reproduction. Male French Bulldogs, for instance, are incapable of mounting the female. For many dogs of this breed, the female must be artificially inseminated in order to reproduce.[58]

Neutering

A wild dog from Sri Lanka nursing her four puppies.

Neutering refers to the sterilization of animals, usually by removal of the male's testicles or the female's ovaries and uterus, in order to eliminate the ability to procreate and reduce sex drive. Because of the overpopulation of dogs in some countries, animal control agencies, such as the American Society for the Prevention of Cruelty to Animals (ASPCA), advise that dogs not intended for further breeding should be neutered, so that they do not have undesired puppies that may have to be destroyed later.[59]

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. Spaying or castrating dogs helps keep overpopulation down.[60] Local humane societies, SPCAs, and other animal protection organizations urge people to neuter their pets and to adopt animals from shelters instead of purchasing them.

Neutering reduces problems caused by hypersexuality, especially in male dogs.[61] Spayed female dogs are less likely to develop some forms of cancer, affecting mammary glands, ovaries, and other reproductive organs.[62] However, neutering increases the risk of urinary incontinence in female dogs,[63] and prostate cancer in males,[64] as well as osteosarcoma, hemangiosarcoma, cruciate ligament rupture, obesity, and diabetes mellitus in either gender.[65]

Intelligence and behavior

Intelligence

The Border Collie is considered to be one of the most intelligent breeds.

The domestic dog has a predisposition to exhibit a social intelligence that is uncommon in the animal world.[27] Dogs are capable of learning in a number of ways, such as through simple reinforcement (e.g. classical or operant conditioning) and by observation.[27]

Dogs go through a series of stages of cognitive development. They are not born with the understanding that objects which are not being actively perceived still remain in existence, called object permanence. This occurs as the infant learns to interact intentionally with objects around it. For dogs, this occurs at roughly 8 weeks of age.[27]

Puppies learn behaviors quickly by following examples set by experienced dogs.[27] This form of intelligence is not peculiar to those tasks dogs have been bred to perform, but can be generalized to myriad abstract problems. For example, Dachshund puppies who watched an experienced dog pull a cart by tugging on an attached piece of ribbon in order to get a reward from inside the cart learned the task fifteen times faster than those who were left to solve the problem on their own.[27][66] Dogs can also learn by mimicking human behaviors. In one study, puppies were presented with a box, and shown that when a handler pressed a lever, a ball would roll out of the box. The handler then allowed the puppy to play with the ball, making it an intrinsic reward. The pups were then allowed to interact with the box. Roughly three-quarters of the puppies subsequently touched the lever, and over half successfully released the ball, compared to only 6 percent in a control group that did not watch the human manipulate the lever.[67] Another study found that handing an object between experimenters who then used the object's name in a sentence successfully taught an observing dog each object's name, allowing the dog to subsequently retrieve the item.[68]

Dogs also demonstrate sophisticated social cognition by associating behavioral cues with abstract meanings.[27] One such class of social cognition involves the understanding that others are conscious agents. Research has shown that dogs are capable of interpreting subtle social cues, and appear to recognize when a human or dog's attention is focused on them. To test this, researchers devised a task in which a reward was hidden underneath one of two buckets. The experimenter then attempted to communicate with the dog to indicate the location of the reward by using a wide range of signals: tapping the bucket, pointing to the bucket, nodding to the bucket, or simply looking at the bucket.[69] The results showed that domestic dogs were better than chimpanzees, wolves, and human infants at this task, and even young puppies with limited exposure to humans performed well.[27] Dr. Stanley Coren, an expert on dog psychology, states that these results demonstrated the social cognition of dogs can exceed that of even our closest genetic relatives, and that this capacity is a recent genetic acquisition which distinguishes the dog from its ancestor, the wolf.[27] Studies have also investigated whether dogs engaged in partnered play change their behavior depending on the attention-state of their partner.[70] Those studies showed that play signals were only sent when the dog was holding the attention of its partner. If the partner was distracted, the dog instead engaged in attention-getting behavior before sending a play signal.[70]

Dr. Coren has also argued that dogs demonstrate a sophisticated theory of mind by engaging in deception, which he supports with a number of anecdotes, including one example where a dog hid a stolen treat by sitting on it until the rightful owner of the treat left the room.[27] Although this could have been accidental, Coren suggests that the thief understood that the treat's owner would be unable to find the treat if it were out of view. Together, the empirical data and anecdotal evidence points to dogs possessing at least a limited form of theory of mind.[27][70]

Behavior

Although dogs have been the subject of a great deal of behaviorist psychology (e.g. Pavlov's dog), they do not enter the world with a psychological "blank slate".[27] Rather, dog behavior is affected by genetic factors as well as environmental factors.[27] Domestic dogs exhibit a number of behaviors and predispositions that were inherited from wolves.[27] The grey wolf is a social animal that has evolved a sophisticated means of communication and social structure. The domestic dog has inherited some of these predispositions, but many of the salient characteristics in dog behavior have been largely shaped by selective breeding by humans. Thus some of these characteristics, such as the dog's highly developed social cognition, are found only in primitive forms in grey wolves.[69]

Interactions with humans

A hunter with a large pack of beagles, a breed of hunting dogs

Domestic dogs inherited a complex social hierarchy and behaviors from their wolf ancestors. Dogs are pack animals with a complex set of behaviors related to determining each dog's position in the social hierarchy, and they exhibit various postures and other means of nonverbal communication that reveal their states of mind.[2] These sophisticated forms of social cognition and communication may account for their trainability, playfulness, and ability to fit into human households and social situations, and these attributes have earned dogs a unique relationship with humans despite being potentially dangerous apex predators.[3]

Although experts largely disagree over the details of dog domestication, it is agreed that human interaction played a significant role in shaping the subspecies.[3] Shortly after domestication, dogs became ubiquitous in human populations, and spread throughout the world. Emigrants from Siberia likely crossed the Bering Strait with dogs in their company, and some experts suggest that use of sled dogs may have been critical to the success of the waves that entered North America roughly 12,000 years ago. Dogs were an important part of life for the Athabascan population in North America, and were their only domesticated animal. Dogs also carried much of the load in the migration of the Apache and Navajo tribes 1,400 years ago. Use of dogs as pack animals in these cultures often persisted after the introduction of the horse to North America.[16]

Health risks to humans

In the USA, dogs cause 88% of the 86,000 falls caused by pets. Dogs can also cause toxocariasis in humans, which can cause blindness, and can also cause human hookworm.[71]. Dog bites form a serious health risk especially to children. The incidence of dog bites in the US is 12.9 per 10000 inhabitants, but for boys aged 5 to 9 the incidence rate is 60.7 per 10000. Moreover children have a much higher chance to be bitten in the face or neck.[72] Sharp claws with powerful muscles behind them can lacerate flesh in a scratch that can lead to serious infections[73].

Work

Dogs have lived and worked with humans in so many roles that they have earned the unique nickname, "man's best friend",[74] a phrase which is used in other languages as well. They have been bred for herding livestock,[75] hunting (e.g. pointers and hounds),[76] rodent control,[2] guarding, helping fishermen with nets, and pulling loads, in addition to their roles as companions.[2]

Service dogs such as guide dogs, utility dogs, assistance dogs, hearing dogs, and psychological therapy dogs provide assistance to individuals with physical or mental disabilities.[77][78] Some dogs owned by epileptics have been shown to alert their handler when the handler shows signs of an impending seizure, sometimes well in advance of onset, allowing the owner to seek safety, medication, or medical care.[79]

Sports and shows

Owners of dogs often enter them in competitions[80] such as breed conformation shows or sports, including racing and sledding.

In conformation shows, also referred to as breed shows, a judge familiar with the specific dog breed evaluates individual purebred dogs for conformity with their established breed type as described in the breed standard. As the breed standard only deals with the externally observable qualities of the dog (such as appearance, movement, and temperament), separately tested qualities (such as ability or health) are not part of the judging in conformation shows.

Differences from wolves

Physical characteristics

Compared to equally sized wolves, dogs tend to have 20% smaller skulls, 30% smaller brains[81], as well as proportionately smaller teeth than other canid species.[82] Dogs require fewer calories to function than wolves. Their diet of human refuse in antiquity made the large brains and jaw muscles needed for hunting unnecessary. It is thought by certain experts that the dog's limp ears are a result of atrophy of the jaw muscles.[82] The skin of domestic dogs tends to be thicker than that of wolves, with some Inuit tribes favoring the former for use as clothing due to its greater resistance to wear and tear in harsh weather.[82] The paws of a dog are half the size of those of a wolf, and their tails tend to curl upwards, another trait not found in wolves.[83]

Behavior

Dogs tend to be poorer than wolves at observational learning, being more responsive to instrumental conditioning.[82] Feral dogs show little of the complex social structure or dominance hierarchy present in wolf packs. For dogs, other members of their kind are of no help in locating food items, and are more like competitors.[82] Feral dogs are primarily scavengers, with studies showing that unlike their wild cousins, they are poor ungulate hunters, having little impact on wildlife populations where they are sympatric. However, feral dogs have been reported to be effective hunters of reptiles in the Galapagos islands,[84] and free ranging pet dogs are more prone to predatory behavior toward wild animals.

Despite common belief, domestic dogs can be monogamous.[85] Breeding in feral packs can be, but does not have to be restricted to a dominant alpha pair (despite common belief, such things also occur in wolf packs).[86] Male dogs are unusual among canids by the fact that they mostly seem to play no role in raising their puppies, and do not kill the young of other females to increase their own reproductive success.[84] Some sources say that dogs differ from wolves and most other large canid species by the fact that they do not regurgitate food for their young, nor the young of other dogs in the same territory.[82] However, this difference was not observed in all domestic dogs. Regurgitating of food by the females for the young as well as care for the young by the males has been observed in domestic dogs, dingos as well as in other feral or semi-feral dogs. Regurgitating of food by the females and direct choosing of only one mate has been observed even in those semi-feral dogs of direct domestic dog ancestry. Also regurgitating of food by males has been observed in free-ranging domestic dogs.[85][87]

Trainability

Dogs display much greater tractability than tame wolves, and are generally much more responsive to coercive techniques involving fear, aversive stimuli, and force than wolves, which are most responsive toward positive conditioning and rewards.[88] Unlike tame wolves, dogs tend to respond more to voice than hand signals.[89] Although they are less difficult to control than wolves, they can be comparatively more difficult to teach than a motivated wolf.[88]

See also

References

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Further reading

  • Abrantes, Roger (1999). Dogs Home Alone. Wakan Tanka, 46 pages. ISBN 0-9660484-2-3 (paperback).
  • A&E Television Networks (1998). Big Dogs, Little Dogs: The companion volume to the A&E special presentation, A Lookout Book, GT Publishing. ISBN 1-57719-353-9 (hardcover).
  • Alderton, David (1984). The Dog, Chartwell Books. ISBN 0-89009-786-0.
  • Bloch, Günther. Die Pizza-Hunde (German), 2007, Franckh-Kosmos-Verlags GmbH & Co. KG, Stuttgart, ISBN 9783440109861
  • Brewer, Douglas J. (2002) Dogs in Antiquity: Anubis to Cerberus: The Origins of the Domestic Dog, Aris & Phillips ISBN 0-85668-704-9
  • Coppinger, Raymond and Lorna Coppinger (2002). Dogs: A New Understanding of Canine Origin, Behavior and Evolution, University of Chicago Press ISBN 0-226-11563-1
  • Cunliffe, Juliette (2004). The Encyclopedia of Dog Breeds. Parragon Publishing. ISBN 0-7525-8276-3.
  • Derr, Mark (2004). Dog's Best Friend: Annals of the Dog-Human Relationship. University of Chicago Press. ISBN 0-226-14280-9
  • Donaldson, Jean (1997). The Culture Clash. James & Kenneth Publishers. ISBN 1-888047-05-4 (paperback).
  • Fogle, Bruce, DVM (2000). The New Encyclopedia of the Dog. Doring Kindersley (DK). ISBN 0-7894-6130-7.
  • Grenier, Roger (2000). The Difficulty of Being a Dog. University of Chicago Press ISBN 0-226-30828-6
  • Milani, Myrna M. (1986). The Body Language and Emotion of Dogs: A practical guide to the Physical and Behavioral Displays Owners and Dogs Exchange and How to Use Them to Create a Lasting Bond, William Morrow, 283 pages. ISBN 0-688-12841-6 (trade paperback).
  • Pfaffenberger, Clare (1971). New Knowledge of Dog Behavior. Wiley, ISBN 0-87605-704-0 (hardcover); Dogwise Publications, 2001, 208 pages, ISBN 1-929242-04-2 (paperback).
  • Shook, Larry (1995). "Breeders Can Hazardous to Health", The Puppy Report: How to Select a Healthy, Happy Dog, Chapter Two, pp. 13–34. Ballantine, 130 pages, ISBN 0-345-38439-3 (mass market paperback); Globe Pequot, 1992, ISBN 1-55821-140-3 (hardcover; this is much cheaper should you buy).
  • Shook, Larry (1995). The Puppy Report: How to Select a Healthy, Happy Dog, Chapter Four, "Hereditary Problems in Purebred Dogs", pp. 57–72. Ballantine, 130 pages, ISBN 0-345-38439-3 (mass market paperback); Globe Pequot, 1992, ISBN 1-55821-140-3 (hardcover; this is much cheaper should you buy).
  • Thomas, Elizabeth Marshall (1993). The Hidden Life of Dogs (hardcover), A Peter Davison Book, Houghton Mifflin. ISBN 0-395-66958-8.
  • Trumler, Eberhard. Mit dem Hund auf du; Zum Verständnis seines Wesens und Verhaltens (German); 4. Auflage Januar 1996; R. Piper GmbH & Co. KG, München
  • Small animal internal medicine, RW Nelson, Couto page 107

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