Fancy rat
The fancy rat is the domesticated form of Rattus norvegicus, the brown rat, and the most common species of rat kept as a pet. The name fancy rat derives from the use of the adjective fancy for a hobby, also seen in "animal fancy", a hobby involving the appreciation, promotion, or breeding of pet or domestic animals. The offspring of wild-caught specimens, having become docile after having been bred for many generations, fall under the fancy type.
Fancy rats were originally targets for blood sport in 18th- and 19th-century Europe. Later bred as pets, they now come in a wide variety of coat colors and patterns, and are bred and raised by several rat enthusiast groups around the world. They are sold in pet stores and by breeders. Fancy rats are generally quite affordable, even compared to other small pets; this is one of their biggest draws. Additionally, they are quite independent, affectionate, loyal and easily trained. They are considered more intelligent than other domesticated rodents. Healthy fancy rats typically live 2 to 3 years, but are capable of living a year or so longer.
Fancy rats are used widely in medical research, as their physiology is similar to human physiology. When used in this field, they are referred to as laboratory rats .
Domesticated rats are physiologically and psychologically different from their wild relatives, and typically pose no more of a health risk than other common pets. For example, domesticated brown rats are not considered a disease threat, although exposure to wild rat populations could introduce pathogens like the bacteria Streptobacillus moniliformis into the home. Fancy rats have different health risks from their wild counterparts, and thus are unlikely to succumb to the same illnesses as wild rats.
History
The origin of the modern fancy rat begins with the rat-catchers of the 18th and 19th centuries who trapped rats throughout Europe. These rat-catchers would then either kill the rats, or, more likely, sell the rats to be used in blood sport. Rat-baiting was a popular sport until the beginning of the 20th century. It involved filling a pit with several rats and then placing bets on how long it would take a terrier to kill them all. It is believed that both rat-catchers and sportsmen began to keep certain, odd-colored rats during the height of the sport, eventually breeding them and then selling them as pets. The two men thought to have formed the basis of rat fancy are Jack Black, self-proclaimed rat-catcher to Queen Victoria, and Jimmy Shaw, manager of one of the largest sporting public houses in London. These two men are responsible for beginning many of the color varieties present today. Black, specifically, was known for taming the "prettier" rats of unusual color, decorating them with ribbons, and selling them as pets.File:Nieuhof-p-263-Googhelaars-Lach-van-Kley-plate-364.png|thumb|Rats performing in a Chinese street circus troupe, as seen by Johan Nieuhof in 1655-57Rat fancy as a formal, organized hobby began when a woman named Mary Douglas asked for permission to bring her pet rats to an exhibition of the National Mouse Club at the Aylesbury Town Show in England on October 24, 1901. Her black-and-white hooded rat won "Best in Show" and ignited interest in the area. After Douglas' death in 1921, rat fancy soon began to fall back out of fashion. The original hobby formally lasted from 1912 to 1929 or 1931, as part of the National Mouse and Rat Club, at which point Rat was dropped from the name, returning it to the original National Mouse Club. The hobby was revived in 1976 with the formation of the English National Fancy Rat Society. Pet rats are now commonly available in stores and from breeders and there exist several rat fancier groups worldwide.
Differences from wild rats
While domesticated rats are not removed enough from their wild counterparts to justify a distinct species, there are significant differences that set them apart; the most apparent is coloring. Random color mutations may occur in the wild, but these are rare. Most wild R. norvegicus are a dark brown color, while fancy rats may be anything from [|white to cinnamon to blue].Behaviorally, domesticated pet rats are tamer than those in the wild. They are more comfortable around humans and known to seek out their owners while roaming freely. They have decreased reactions to light and sound, are less cautious of new food, and have better tolerance to overcrowding. Domesticated rats are shown to mate earlier, more readily, and for a longer period of time over their lifespan. Also, domesticated rats exhibit different behaviors when fighting with each other: while wild rats almost always flee a lost battle, caged rats spend protracted amounts of time in a belly-up or boxing position. These behavioral traits are thought to be products of environment as opposed to genetics. However, it is also theorized that there are certain underlying biological reasons for why some members of a wild species are more receptive to domestication than others, and that these differences are then passed down to offspring.
The body structure of domesticated rats differs from that of a wild rat as well. The body of a fancy rat is smaller, with larger ears and a longer tail. Domesticated rats have generally smaller and sharper facial features as well.
Domesticated rats have a longer lifespan than that of wild rats. Because domesticated rats are protected from predators and have ready access to food, water, shelter, and medical care, their average lifespan is around two to three years, in contrast to wild R. norvegicus, which average a lifespan of less than one year. However, wild rats generally have larger brains, hearts, livers, kidneys, and adrenal glands than laboratory rats. The fancy rat and wild rat also each face a multitude of differing [|health concerns]; the former is at risk of developing a pneumococcal infection from exposure to humans, while the latter may harbor tapeworms after coming in contact with carriers such as cockroaches and fleas.
Varieties
As in other pet species, a variety of colors, coat types, and other features that do not appear in the wild have either been developed, or have appeared spontaneously. Fancy rats in themselves are a subspecies and as such do not have distinctive breeds. Any individual rat may be defined one or more ways by its color, coat, marking, and non-standard body type. This allows for very specific classifications such as a ruby-eyed cinnamon Berkshire rex Dumbo.Coloring
While some pet rats retain the agouti coloring of the wild brown rat, others have solid colors, a trait derived from rats with black coats. Agouti-based colors include agouti, cinnamon, and fawn. Black-based colors include black, beige, blue, and chocolate.Eye color is considered a subset of coloring, and coat color definitions often include standards for the eyes, as many genes which control eye color will also affect the coat color or vice versa. The American Fancy Rat and Mouse Association lists black, pink, ruby, and odd-eyed as possible eye colors, depending on the variety of rat shown. Ruby refers to eyes which at a glance appear black, but on closer observation are a deep, dark red.
Color names can vary for more vaguely defined varieties, like lilac and fawn, while the interpretations of standards can fluctuate between different countries or clubs.
Markings
Further dividing the varieties of fancy rats are the many different markings. Fancy rats can appear in any combination of colors and markings. The markings are typically in reference to the patterns and ratios of colored hair versus white hair. Two extremes would be a self and a Himalayan.Markings have a strict standard, with detailed terminology, for showing in fancy rat pet shows. However, many domestic rats are not closely bred to any color standard; many of those found in pet shops will have mismarkings from a formal breeding perspective, which are defined as variations in markings that are not recognized as conforming to a breed standard published by a rat fancier organisation.
Commonly recognized standards include:
- Berkshire – colored top, white belly
- Hooded – color runs in a saddle, a single, unbroken line from the full head down to the spine and possibly partly down the tail
- Capped – color on the full head only
- Blazed – colored head or body with a triangular wedge of white fur over the face.
- Variegated – any form of mismatched oddities in the fur. Can be anything from a broken or spotted hood to a misshaped blaze.
- Irish or English Irish – In England, the Irish is standardized by the NFRS as an equilateral triangle of white with a side that begins at the chest, or between the front legs, and where the point ends mid-length. In the United States and elsewhere, clubs like the AFRMA distinguish this marking as the English Irish and allow for another standardized Irish in which the rat may have white of an even or symmetrical nature anywhere along its underside.
Ear and body type
Two of the most prominent and standardized physical changes applied to rats through selective breeding are the development of the Manx rat and Dumbo rat. The Dumbo rat, whose origins are in the United States, is characterized by having large, low, round ears on the sides of its head, versus the smaller and less prominent ears seen on a standard eared rat. Dumbo ears are caused by a recessive mutation, and was named for its resemblance to the fictional character Dumbo the Flying Elephant. The Manx rat is tailless due to a genetic mutation, and was named for the Manx cat which shares this feature, though not necessarily due to the same mutation. Breeding Manx rats does raise some ethical and health concerns however, as rats use their tails for both balance and thermoregulation.Another body type variation that has risen to prominence more recently in the hobby is the Dwarf rat. Dwarfism arose as a mutation among Sprague-Dawley rats kept for research in the 1970s. Adult dwarfs are considerably smaller than their standard counterparts, with males between 100 and 130g as opposed to 300g or more. This strain of dwarfism is caused by reduced production of growth hormone, and this has other effects in addition to changed overall body size. Important for pet-keeping, it reduces the incidence of pituitary and mammary tumours and nephropathy, with the result that Dwarf rats live 20–40% longer in males and 10–20% longer in females than their standard counterparts. However, they may also show some cognitive impairment.