Herbivores appear less susceptible than carnivores; a number of reptiles that seldom become affected or die can serve as carriers, including garter snakes, northern black racers, and box turtles. Proceedings of the Royal Society of London. In traditional taxonomy, the Synapsida encompasses two distinct grades successively closer to mammals: Multifocal abscesses in a swollen, friable liver are seen in the hepatic form. Vertebrate Paleontology , 3rd ed.
When human influence removes larger predators, many of the smaller carnivores become extremely abundant, creating an ideal environment for the spread of infection. The disease of most concern to humans is rabies , which is transmitted in saliva via bites. Rabies is most common in the red fox , striped skunk, and raccoon, but it also occurs in African hunting dog s and can infect practically all carnivores.
Billions of dollars are spent annually throughout the world to manage and control the incidence of this disease. In some countries, abundance of vector species, especially red fox es, is controlled by culling or by dropping vaccine-laden bait from the air. Other infectious diseases carried by carnivores and of concern to humans include canine distemper , parvovirus , toxoplasmosis , and leptospirosis.
Carnivores rank high on the scale of intelligence among mammals. The brain is large in relation to the body, an indication of their superior mental powers. For this reason, these animals are among the easiest to train for entertainment purposes, as pets, or as hunting companions. The highly developed sense of smell among dogs, for instance, supplements the sharper vision of man. Dogs are the carnivores most commonly trained for hunting, but the cheetah , caracal , and ferret have also been used to some extent.
In China the otter is trained to drive fish under a large net, which is then dropped and pulled in. Dependent for survival upon their ability to prey upon living animals in a variety of situations, carnivores have evolved a relatively high degree of learning ability see animal learning. Carnivorous mammals tend to establish territories, though omnivorous carnivores, such as the black bear , striped skunk , and raccoon , are less apt to do so.
Territories are often exclusive , defended by the residents against other animals of their own kind. Such areas may sometimes be marked by secretions produced by anal or other scent glands and by deposition of feces in prominent locations. There is a wide range of social patterns among carnivores. Many bears, various foxes, genet s, most cats, and most mustelids are solitary except during the breeding season.
Some remain paired throughout the year black-backed jackal and lesser panda or occasionally roam in pairs gray fox , crab-eating fox , and kinkajou. Other carnivores, such as the wolf , African hunting dog , dhole , and coati , normally hunt in packs or bands. Various pinniped s form sedentary colonies during the breeding season, sea otters congregate during a somewhat larger part of the year, and meerkat s are permanently colonial.
Mating systems vary among families, ranging from monogamy in the wolf and polygyny in most bears and mustelids to harems in elephant seal s. Copulation is vigorous and frequent in many species, including the lion, and many species possess reproductive peculiarities as adaptations to their environments.
Induced ovulation, for instance, allows females to release egg cells during or shortly after copulation. Delayed implantation of the fertilized egg in the wall of the uterus is another phenomenon that allows births to occur when resources are abundant. This phenomenon is most prominent in species living in highly seasonal environments. Delayed implantation is most extreme in the pinnipeds and bears but is absent from canines. The smallest living member of Carnivora is the least weasel Mustela nivalis , which weighs only 25 grams 0.
The largest terrestrial form is the Kodiak bear Ursus arctos middendorffi , an Alaskan grizzly bear that is even larger than the polar bear Ursus maritimus. The largest aquatic form is the elephant seal Mirounga leonina , which may weigh 3, kg 8, pounds. Most carnivores weigh between 4 and 8 kg 9 and 18 pounds. The vast majority of species are terrestrial, but the pinnipeds are highly adapted to life in the water. Some nonpinnipeds, such as the sea otter , are almost fully aquatic, while others, such as the river otter and polar bear, are semiaquatic, spending most of their lives in or near water.
Aquatic and semiaquatic forms have developed specializations such as streamlined bodies and webbed feet. Carnivores, like other mammals, possess a number of different kinds of teeth: Most carnivores have carnassial, or shearing, teeth that function in slicing meat and cutting tough sinews.
The carnassials are usually formed by the fourth upper premolar and the first lower molar, working one against the other with a scissorlike action. Cats, hyenas, and weasels, all highly carnivorous, have well-developed carnassials. Bears and procyonids except the olingo , which tend to be omnivorous, and seals, which eat fish or marine invertebrates, have little or no modification of these teeth for shearing. The teeth behind the carnassials tend to be lost or reduced in size in highly carnivorous species.
Most members of the order have six prominent incisors on both the upper and lower jaw, two canines on each jaw, six to eight premolars, and four molars above and four to six molars below. Incisors are adapted for nipping off flesh. The outermost incisors are usually larger than the inner ones. The strong canines are usually large, pointed, and adapted to aid in the stabbing of prey. The premolars always have sharply pointed cusps, and in some forms e. Except for the carnassials, molars tend to be flat teeth utilized for crushing.
Terrestrial carnivores that depend largely on meat tend to have fewer teeth 30—34 , the flat molars having been lost. Omnivorous carnivores, such as raccoons and bears, have more teeth 40— Pinnipeds have fewer teeth than terrestrial carnivores. In addition, pinnipeds exhibit little stability in number of teeth; for example, a walrus may have from 18 to 24 teeth.
Several features of the skeleton are characteristic of the order Carnivora. Articulating surfaces condyles on the lower jaw form a half-cylindrical hinge that allows the jaw to move only in a vertical plane and with considerable strength. The clavicles collarbones are either reduced or absent entirely and, if present, are usually embedded in muscles without articulation with other bones.
This allows for a greater flexibility in the shoulder area and prevents breakage of the clavicles when the animal springs on its prey. The brain is large in relation to the weight of the body, and it contains complex convolutions characteristic of highly intelligent animals.
The stomach is simple as opposed to multichambered, and a blind pouch cecum attached to the intestine is usually reduced or absent. The teats are located on the abdomen along two primitive lines milk ridges , a characteristic of mammals that lie down when nursing.
Many carnivores have a well-developed penis bone, or baculum. It appears that this structure plays a role in helping to increase the success of copulation and fertilization of eggs in species where numerous males mate with a single female.
Cats have a vestigial baculum or none at all, but the baculum of the walrus can measure up to 54 cm 21 inches. Carnivores are found worldwide, although Australia has no native terrestrial members except for the dingo , which was introduced by aboriginal man.
Terrestrial forms are naturally absent from most oceanic islands , though the coastlines are usually visited by seals. However, people have taken their pets, as well as a number of wild species, to most islands. For example, a large population of red foxes now inhabits Australia, having been introduced there by foxhunters. Introduction of carnivores to new environments has at times devastated native fauna. In New Zealand , stoats, ferret s and weasel s were introduced to control rabbits, which had also been introduced.
As a result, native bird populations were decimated by the carnivores. Birds were also a casualty of mongoose s introduced to Hawaii and Fiji, where populations of introduced rodents and snakes had to be controlled. In Europe, American mink s released from fur farms contributed to the decline of the native European mink. Because carnivores are large and depend on meat, there must be fewer carnivores in the environment than the prey animals they feed upon. In general, carnivores have a population density of approximately 1 per 2.
By comparison, omnivorous mammals average about 8 per square km 20 per square mile , and herbivorous rodents attain densities of up to 40, per square km , per square mile at peak population. Relatively low population density makes carnivores vulnerable to fluctuations of prey density, habitat disturbance, infectious disease , and predation by man.
The mobility and adaptability of some carnivores has enabled them to shift ecological roles and survive changes brought about by human activities. For example, the red fox, coyote , raccoon, and striped skunk can all be found in urban and suburban areas of North America. In Europe, the red fox lives in most large cities. Most other species do not fare nearly as well. The gray, or timber, wolf and brown bear once lived across much of the Northern Hemisphere, but their ranges have shrunk following habitat destruction, reduction of prey abundance, and persecution as competitors with man.
In Africa and southern Asia the same can be said for lions and tigers. Numerous cats and bears and some seals have become rare and are threatened with extinction. There is great diversity in Carnivora, especially among the highly specialized pinnipeds. Thus, the characteristics used to separate Carnivora from other mammalian orders and to define the subdivisions of Carnivora are primarily structural. Of great importance are certain features of the skull such as jaw articulation , feet number of toes, lack of opposability of the hind toe, type of claws, and fusion of certain bones , and teeth both the overall tooth pattern and the shape of individual teeth.
Dentition is especially important in determining the relationships of fossil forms. The only parts they do not digest and utilize are teeth and nails. This way Mother Nature makes sure cats get all the nutrients they need to thrive and live a healthy life.
The bones presented in the prey contain nutrients, such as calcium, in a perfect, balanced way. When feeding raw bones to cats be sure that they are small enough that your cat can chew on them. Examples include chicken wings, ribs and necks, Cornish Hen cuts, many cuts from small rabbits, and many other small poultry such as quail. You can also offer small whole prey such as mice and chicks. Cats are not silly and they will screen very thoroughly to make sure the bone is suitable to chew on.
You must observe how your cat attacks bones, and take note of her next couple of bowel movements to see whether she is eating the actual bone. If the stools are bloody, if there is any indigestion, discomfort, gas, vomiting, bloating or if there are any shards of bone in the stool, then discontinue feeding whole bones. If your cat is constipated, then you may need to reduce the amount of bone you are feeding.
Doing so can cause the bones to splinter, making them sharp with the possibility of puncturing the intestinal system. When you feed a cat bone-in cuts of meat, such as chicken wings or necks, the cat has to use their side teeth to chew and cut the meat into pieces small enough to swallow.
This vigorous use of the side teeth helps to keep the teeth clean, the gums stimulated and the jaws exercised. This is not only beneficial to their dental health, but helps to keep them mentally stimulated. Calcium is the most abundant mineral in the body. By the time you see symptoms of a calcium deficiency, your cat has often been calcium deficient for months or years. That is why it is so important that everyone who has their kitten on a raw food program be sure their animal is getting sufficient level of this important nutrient.
Most of the calcium in the body is utilized by the bones and teeth. However, it is also involved in the blood-clotting process, in nerve and muscle stimulation, parathyroid hormone functions and the metabolism of vitamin D. To function properly along with the high phosphorus content in meat, calcium must be accompanied by magnesium, boron, copper, molybdenum, potassium, sulphur, zinc and vitamins A, B6, D and E.