Lioncrusher's Domain -- Felidae

There are 37 species of cats, coming in all shapes, sizes, colors, habitats, and behaviors. But there are several things that link them all together as cats. All cats, from the Siberian tiger (the largest living cat) to the rusty spotted cat (at 2 lb., the smallest living cat) are all in the family Felidae, or the cat family.

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora

Suborder: Feliformia

Family: Felidae

Subfamily: Felinae (Felinae cats (all other genera)
Subfamily: Pantherinae (Genera Panthera, Uncia, Neofelis)
Subfamily: Machairodontinae (Sabre-toothed cats; EXTINCT)

Until recently, all cat species were assigned to a limited number of genera. Virtually all of the smaller cat species were assigned to the genus Felis. Just like in many other families, taxonomic authorities tended to be "lumpers", placing as many like species in one genus as possible, rather than "splitters", who split species into smaller genera based on genetic, structural, and geographic similarities and differences. The conservative approach of lumping species together under a single genus and having several subgenera, raises the question of why the subgenus taxon exists in the first place, if not to split apart animals within a genus. Subgenera exist to show that two animals are more similar to each other in a genus than to others in the same genus, but are superfluous.

Wilson and Reeder, apparently thought so too, because in 1993 they published their work: Mammal Species of the World: A Taxonomic and Geographic Reference. The organization of most families of mammals were affected by this work, which redefined the relationships of many mammal species; for instance, taking the mongooses out of the Viverridae family. This impacted the way the felid family is organized, and most authorities accept this new classification system. For a list of the old and new taxon, visit the Felid Taxon Advisory Group's website.

It is worth mentioning that Ewer (1973) (in her book The Carnivores, Cornell University Press) recognized all the current genera, while all her collegues at the time disregarded this and placed most felids in the genus Felis.

It should be kept in mind that there are two basic groups of cats, excluding the cheetah: Feline (lesser cats, including the genera Lynx) and Pantherine (big cats). These two groups share many attributes, but also differ in many ways. The major difference between the Big cats and the Lesser cats is the ability to roar. The Big cats' larynx is much more flexible, with much of the bony structure replaced by cartilage, but the lesser cats have a more rigid larynx structure, making roaring impossible. However, contrary to popular belief, all cats purr, but Pantherine cats can only purr while exhaling, while Feline cats can purr while both inhaling and exhaling. Big cats tend to lie down when they eat, and smaller cats tend to crouch.

Skull and Teeth:

All cats have a similar skull shape - a short, rounded skull, short muzzle, large eye sockets, thick sturdy jaw bones, and a very prominent saggital crest. The saggital crest is used in larger cats as an anchor for the large temporalis muscle (powerful jaw muscle), since there is not enough room on their skull for it to attach to the side of the head like smaller cats. Felids and other Feloidean carnivores also are distinguished by having auditory bullae that have two chambers.

All cats also posses very lethal weapons in their mouth - their canine teeth, which are very large and sensitive to pressure. The canine teeth of cats are the most highly developed of all carnivores. And they also have the least number of teeth in their skull, due to the shortening of the skull. Cats have, generally speaking, 16 teeth in the upper jaw and 14 in the lower, totalling around 30 teeth on average. Some cats have even less. Cats need less teeth than other carnivores since they do not eat as much vegetation and thus do not have the need for the grinding teeth known as molars. Cats also have highly developed carnassial teeth, which are the shearing teeth, and the hallmark of the order Carnivora. These teeth are located in the sides of the mouth and are used to shear apart meat into smaller pieces. In less developed carnivores, like weasels and bears, the carnassials are smaller and less powerful. Also, unlike animals that eat a lot of vegetation, cats can only move their jaws in one direction -- up and down. They cannot move their jaws from side-to-side. The reason they cannot move their jaw in other directions has to do with the way the carnassial teeth work, they only work up and down (like scissors) and cannot shear on an angle. To get the maximum effect, cats only use one side of their mouth when eating, to maximize leverage. Cats have a large gap between their canine teeth and their carnassials, so the canine can be plunged its full-length into the animal. Cats incisor teeth (small teeth located at the front of the mouth) are very small and arranged in a straight line, unlike other mammals who have theirs in a curved arrangement. These teeth help the cat grip its prey effectively without getting in the way.

Fur and Skin:

The skin of cats is very flexible and loose, to minimize damage from bite and scratch wounds. Fur is typically dense and short, and provides insulation from the elements. Cats have four types of hairs covering their body. The thickest are the whiskers, also known as vibrissae, which are primarily located on the face. Second thickest are special sensory hairs found all over the body that are longer than the rest of the fur. These hairs are sparse, and found evenly all over the cats body about every few inches or so, and the purpose of these hairs is the same as whiskers, only for the body. Third thickest and second numerous are the guard hairs, which are numerous and dense and protect the body from moisture and particles. The finest and most numerous hairs are the soft undercoat. These hairs have a much smaller diameter than guard hairs; about 20 - 40 or so underhairs occupy a single hair shaft with a guard hair. These hairs have a crimped appearance, and help protect the cat from heat and cold.

The most important purpose of cat's hair is camouflage. The stripes on a tiger, the spots on a leopard, and the tabby markings and coloration on a European wild cat all serve to help the cat blend into its surroundings. Cats that inhabit woods tend to be darker than those on the plains, and are also more brilliantly marked. Melanism (unusual dark color) also occurs frequently in cats, especially cats found in thick jungle. In melanistic cats, the ground coloration is extremely dark, almost black, with the markings (spots, rosettes) still able to be seen. In general, most spotted cat species have a melanistic variety. A color morph known as leucism also exists, and has been confirmed in the tiger, lion, and serval, as well as other species. In leucism, the color is unusually light to white, with the markings overtop. These cats are not true albinos, as they still have melanin in their cells, and have color to them, such as their markings and their blue eyes. Another color morph is called erythrism. Erythristic individuals have markings that are reddish in color, rather than the usual black.

For more information and lots of illustrative images on feline coloration, visit this site: Mutant Big Cats.

Skeletal and Muscular Structure:

With the sole exception of the cheetah, cats bodies are not designed for speed, but rather stealth and power. Cats are digitigrade, meaning they walk on their toes rather than on their entire foot, like a human or bear. Most cats are well-equiped for climbing trees, with their sharp, retractable claws (exception: cheetah), relatively short and stocky legs, and their long yet compact body. Cats can also climb down a tree forwards and backwards, due to a very flexible ankle joint. Cats vertebrae are very flexible, and they are capable of contorting themselves into almost any position. This also minimizes damage caused from a fall to their limbs and internal organs.

Cats have sharp backwards facing barbs on their penis that are used to stimulate ovulation, as female cats are induced ovulators, meaning they will not ovulate before mating. This, coupled with the fact that more than one egg is released at a time and at different times, means that kittens or cubs in a litter can have different fathers. Unlike most other carnivores, cats have a vestigial or absent baculum.

Cats are, with the exception of the lion, solitary creatures. A male and female only come together to mate, and afterwards the male has nothing to do with his progeny, leaving the female to raise her offspring by herself. Mating is usually a very violent affair, with screams and yelps coming from the female, and hissing and growling from the male. Despite all this, cats come together to mate several times during the mating period; lions mate over 200 times! Cats are territorial. Generally, males have larger ranges than the females, and one male's range may overlap with several females' ranges. Females' ranges often overlap with other females' ranges as well, but two males' ranges never overlap. Boundaries are marked with urine, which is sprayed on trees and other raied objects, and excretions from glands located on the face: above the eyes, on the cheeks, and under the chin. Feces is usually buried, and rarely ever used to mark boundaries. Cats are semi-arboreal, meaning they are agile climbers, and can spend a great deal of time in the trees, but live mostly on the ground.

Cats are predators, and feed primarily on meat. They will supplement their diet with some grasses, but this does not make up a significant portion of their diet. Cats are the most highly advanced predators in the order Carnivora. Their exclusive meat diet is indicated by several factors. Their jaw is shortened, and they have fewer teeth, to allow a more powerful downward bite. The carnassial and canine teeth are highly developed. Their small intestine is shortened, since meat does not take as long to digest as vegetation. Their claws have incredible tensile strength, and are very sharp and retractable. Their bodies are densely muscled. With the exception of the lion, and sometimes the cheetah, cats hunt alone, stalking their prey from a distance, then sprinting when they are close enough to kill. Smaller prey is often killed by severing the spine, while larger prey is suffocated by a bite to the throat or covering the nose and mouth.

Cats range on all continents except Antarctica and Australia. The majority of cat species are found in the tropic and subtropic areas, with a few species being found in the nearctic. Cats don't have the wide range that dogs have since they have a very specific diet. Dogs can be found everywhere since their diet is so varied. Cats are typically very secretive, and usually it is not known that they are even present throughout most of their range. Since cats don't typically live in large groups, they are harder to spot.

All cats have highly developed senses, especially the senses of sight and hearing. The sense of smell is not as highly developed as it is on other carnivores since the cats rely heavily on sight to hunt and not scent. Rather they use a blend of sight and hearing to locate prey.

Eyesight:

The cats sense of sight is probably the most highly developed in the order Carnivora. It is their primary means of locating prey. The reason sight is so highly developed is because most cats hunt at nighttime, when little light is available. To adapt to low light, cats like many carnivores have a special layer on the back of the retina called the tapetum lucidum. This special cell layer takes the light coming into they eye, magnifies it and reflects it to the retina, like an amplifier. Cats eyes are also relatively large compared to other carnivores, which allows the pupils to increase in size a greater distance. Also, the cornea and lens are more sharply curved, which increases the sensitivity of the retina. The retina contains two types of cells: rods and cones. Rods are more responsive to lower levels of light than cones, thus cats have more rods than most mammals. Cats can also control the amount of light coming into their eyes better than other mammals. The little cats, who have a slit-shaped pupil, can close their pupils almost entirely, and open them to cover their entire eye. Bigger cats eyes, although they don't look it, are in fact elliptical in shape, just to a lesser degree. Cats, being carnivores, have their eyes located on the very front of their face, which allows depth perception, and accuracy, both of which are very important in hunting. However, cats eyes are located more closely together than those of other carnivores, making their binocular vision better than dogs or bears.

Domestic cat (Felis catus) eyes, illustrating change in pupilar size.

Hearing:

In addition to sight, cats use hearing to locate prey. Most cats have huge ears, which are cone-shaped to funnel sound to the inner ear. They can hear at a range from 200 Hz to 100 kHz. This sensitivity is necessary to locate "silent" prey like mice and voles that have very high pitched calls, and also to hear very quiet sounds, like the sounds of a mouses' footsteps on dirt several yards away. The ears are also mobile, enabling them to locate the source of a sound with moderate accuracy.

Smell:

Cats rely less on their sense of smell than other carnivores for locating prey, but smell is very important for communication. Cats, like other carnivores, have a structure called a vomeronasal organ, located in the roof of the mouth, that is used to detect chemicals in the air. Cats use this organ by opening their mouth in the "flemen" posture, which looks like a grimace. They curl their lips up, bare their teeth, wrinkle their nose, and raise their head. Cats will often do this when they detect the smells of another cat of the same species. This organ is most often used to detect certain chemicals found in urine and feces, which are signals of readiness to mate.

Cat's noses also have a slit that extends from the corner of each nostril. This is thought to allow the cats to breathe while their face is submerged in a carcass.

A tiger's nose The nose of a tiger, (Panthera tigris), illustrates the shape of cats noses. Here you can clearly see the slits extending from the corner of each nostril.

Taste and the tongue:

The cat's tongue is covered with hundreds of minute sharp projections known as papillae. They point backwards on the tongue, and are used to rasp the meat off of the bones. Cats also groom themselves with their tongues. Since cats do not eat much vegetation, they have no need to detect sugars in their diet, Thus cats can taste sour, bitter and salty, but have a limited ability to detect sweetness.

Touch and the Whiskers:

Cats' faces are covered in very sensitive thick hairs known as whiskers, or vibrasse. These hairs can detect minute vibrations in the air, and can let a cat feel its way around in the dark or in a dark passageway. These hairs, which have numerous nerve endings at their base, are located above the eyes, on the cheeks, on the muzzle, and on their chin, as well as on the backs of the legs. The largest whiskers, those on the muzzle, are supplied by nerves through the infraorbital foramen. Scientists can judge by the size of the foramen on the skulls of cats how sensitive their whiskers were, and this gives the sceitists a clue on how extinct cat species lived. Example: a small foramen found on an extinct species of cat, like the ancestors of the cheetah, indicate less sensitive and therefore smaller and less numerous whiskers. A large foramen indicated larger and more numerous whiskers, so would indicate a cat that spend a lot of time in the forests, an area they would need sensitive whiskers.

The hairs have different names depending on where they are found on the body. The hairs on the muzzle, known as mystacial whiskers, are the most developed. These whiskers are mobile, and are used not only for detection, but for showing mood. These tend to be the longest, thickest, most numerous and most sensitive of the whiskers. Whiskers above the eyes are called supercilliary whiskers. These are second numerous. Whiksers on the cheeks are called genial whiskers. These usually are sparse and thinner. The whiskers found on the chin are called gular whiskers. Carpel hairs are whiskers found on the back of the legs.

Cats, though for the most part solitary, have a complex communication system. Cats communicate in a variety of ways, from scent to visual to vocal. Cats will regularly mark off their territory with urine. Small cats bury their feces, large cats do not. Also, some male cats do not bury their feces, and use this as territorial markers. Cats also use a substance secreted from the anal glands to mark. Scent glands are located on the chin and paw pads, and are used to mark. Clawing at a tree has many uses: it sharpens the claws by removing the outer layer, it deposits scent from their paw pads and it leaves a visual signal. Cats detect chemicals in the urine by using a technique called flemen, described above in the Smell section of the Senses.

Cats also vocalize, using a wide range of sounds, from roaring, growling, hissing, purring, chuffing, chirping, mewing and meowing. Roaring is used as a warning, as is growling and hissing, chuffing is used by large cats as a kind of content sound, purring is another contented sound that can be produced by ALL cats, chirping is made by cheetahs to call their young, and mewing and meowing can have many meanings.

Cats also have a wide range of body postures they use to communicate moods, just like the dog family. They use their tails, ears, whiskers and facial expression to tell other cats their mood. A tail standing up vertically is a form of greeting by cats, a tail standing out straight vertically from their body means they will attack, a tail held low to the ground vertically or with a slight curve at the tip indicates relaxation, and a tail arched up then down (sometimes with the hair standing on end) indicates fear. The ears are normally held forward, but if the ears are flattened against the head, revealing the white dots that are often found on the backs of cat's ears, it means the cat is either fearful or aggressive. Ears held out to the sides indicate suspicion or confusion. Cats have the most expressive face in the Carnivore order. The slightest change in their face can indicate one of hundreds of emotions or moods. But there are tell-tale signs of certain moods. A complacent mood is indicated by a relaxed face, whiskers are often pushed forward on the face, ears are pricked, and the body is held normally. Aggression is indicated by the lips being curled back to reveal their teeth, the nose crumpled up, ears are laid back, and the whiskers are pulled flat against the face, and the body often is flat on the ground.

All of the lines of carnivores evolved from a group of small weasel-like insectivores called Miacids, which existed 60-55 mya. These small mammals had the beginnings of the carnassial, the meat-shearing teeth found in the jaws of all carnivores. The miacids split into two groups: Miacidae and Viverravidae. It appears that the Miacidae family went on to become Arctoidea/Canoidea group, while the Viverravidae became the Aeluroidea/Feloidea group around 48 mya.

The miacid that became the Viverravidae group evolved to produce Proailurus, the first "true cat", about 30 mya. Proailurus was a small cat, and had a body structure more like a miacid than a modern cat, with shorter legs and a long body. They had one more premolar on each side of their bottom jaw than do modern cats. The most well known species of Proailurus was P. lemanensis, the fossils of which were discovered in France.

About 20 mya, Proailurus gave rise to Pseudaelurus, which split into two major groups, one of which evolved into the Machairodontinae subfamily (the true sabre-tooth cats), and the other evolved into Schizailurus, which is the ancestor of all modern Felidae species. Some believe that certain branches of Nimravidae evolved to give rise to Proailurus, but this is not the case. It is most commonly believed that the nimravids and the felids evolved separately, and the last common ancestor between them was the miacids. Sabre-toothed feline-like animals evolved separately four times in evolutionary history: in Nimravidae, Felidae, Creodonta, and the thylacosmilids (sabre-toothed marsupials), due to a process called convergent evolution, where similar structures evolve in unrelated animals, such as the wings of birds and bats.

18 mya, the first modern Felidae to evolve from Schizailurus was the Acinonyx genera, of which only the modern Cheetah (Acinonyx jubatus) still lives. Acinonyx pardinensis (giant cheetah of Eurasia) was significantly larger than the modern day cheetah, with a shoulder height of 90 cm. They were built much the same as the modern A. jubatus, and were specialized sprinters as well. They were found in Europe and Asia around 7.5 - 3 mya. Acinonyx intermedius was found in China 3.8 - 1.9 mya, and it was smaller than the modern cheetah.

12 mya, the Felis genera had evolved. Two of the first modern Felis species were Felis lunensis (Martelli's cat), and Felis manul (Pallas' cat). Martelli's cat is extinct, but the Pallas' cat is still alive. Felis attica is thought to be the ancestor of all modern Felis cats. Other extinct species in the genus Felis were: Felis bituminosa, Felis daggetti, Felis issiodorensis, and Felis vorohuensis.

4 mya, the genus of Miracinonyx had evolved, which became extinct 10,000-20,000 ya. These were cheetah-like cats that lives in North America. Two species have been identified: Miracinonyx inexpectatus and Miracinonyx trumani. Like cheetahs, they had rounded skulls with a very shortened rostrum, and the legs had slim, elongated bones. Unlike cheetahs, these cats had retractable claws and were not as lithe. They were larger than modern cheetahs, and had a body type halfway between a modern cougar and cheetah.

By 3 mya, the Panthera genera had evolved. These cats are characterized by the appearance of an elastic ligament in the hyoid apparatus, which allows these cats to give their characteristic roar. This genus contained several extinct species, including the following: Panthera atrox (American lion), Panthera gombaszoegensis (European jaguar), Panthera leo spelaea (Cave Lion), Panthera palaeosinensis (primitive leopard), Panthera pardoides (primitive leopard), Panthera schaubi, and Panthera toscana (Tuscany lion).

More so in the Felidae family than any other family is the occurrence of hybridization, or the resulting offspring between a male and female of two completely different species. A species is defined and separated taxonomically from other similar species by 2 factors: its ability to mate with others of the same species and produce offspring, and the inability to produce fertile offspring when mated to another species. For example, domestic dog breeds, from the Siberian husky to the poodle, from the Chihuahua to the Great Dane, are all the same species, Canis lupus familiaris, and all can mate with each other and produce young that are fertile, or have the ability to procreate, despite the wide range of size, structure and pelage. All dog breeds are genetically identical. However, a horse and a donkey, though genetically very similar, are two completely different species, and the result of mating the two together would be, generally, an infertile offspring.

In the wild, hybridization is almost non existent. Even in areas where similar species overlap, hybridization does not occur because animals are generally only stimulated by sexual cues from their own species. However, in captivity, animals can usually be easily hybridized with other species, because they are not in a wild state.

The most common hybrids that are created in captivity in Felidae are Tiger-Lion crosses, also known as Tiglons (male tiger x female lion) or Ligers (male lion x female tiger). Tigers and lions are very similar genetically, though are not the same species. They were one of the last species to diverge from one another in the cat family. Male tiger-lion crosses are always sterile, but a very small percentage of females have the ability to procreate, and are often mated to another lion or tiger, creating li-ligers, li-tiglons, ti-ligers, and ti-tiglons. All varieties of hybrids can be much larger than their parents. Some tiglons can weigh over 900 lb. They display a mix of physical traits from their parents, often having a darker tawny background, sometimes with an orangish tinge, with faint medium to dark brown tiger stripes, and lighter coloration around the eyes, muzzle, and undersides. The markings are not as prominent on the hybrids, and are usually restricted to the face. Males often sport manes, although they are much shorter and less dense. Females and many males that lack manes also lack the thick facial ruff seen in tigers.

Another type of hybrid that has been created is the lion-leopard cross, also known as the leopon. These cats tend to have the general appearance of a lion, with a smaller head, and brownish rosettes. They are smaller than a lion but larger than a leopard. Males can have manes, but they are usually very sparse. Their tails have the tuft of hair at the end like lions.

Tiger - leopard crosses are very uncommon, and are virtually unknown. No known photographs or pelts exist, but it is assumed that it is possible to breed the two together.

Other hybrids that have been created are: bobcat/lynx, and serval/caracal. It is also becoming popular to cross domestic cats with wild cats like the Jungle Cat (Felis chaus), creating the breed known as the Chausie, and the Asian Leopard Cat (Felis bengalensis), creating the Bengal cat. The claim is that the cat will have the good nature of the domestic cat while preserving the wild appearance of the wildcats.