Rabbit


Rabbits, or bunnies, are small mammals in the family Leporidae, which is in the order Lagomorpha. They are familiar throughout the world as a small herbivore, a prey animal, a domesticated form of livestock, and a pet, having a widespread effect on ecologies and cultures. The most widespread rabbit genera are Oryctolagus and Sylvilagus. The former, Oryctolagus, includes the European rabbit, Oryctolagus cuniculus, which is the ancestor of the hundreds of breeds of domestic rabbit and has been introduced on every continent except Antarctica. The latter, Sylvilagus, includes over 13 wild rabbit species, among them the cottontails and tapetis. Wild rabbits not included in Oryctolagus and Sylvilagus include several species of limited distribution, including the pygmy rabbit, volcano rabbit, and Sumatran striped rabbit.
Rabbits are a paraphyletic grouping, and do not constitute a clade, as hares are nested within the Leporidae clade and are not described as rabbits. Although once considered rodents, lagomorphs diverged earlier and have a number of traits rodents lack, including two extra incisors. Similarities between rabbits and rodents were once attributed to convergent evolution, but studies in molecular biology have found a common ancestor between lagomorphs and rodents and place them in the clade Glires.
Rabbit physiology is suited to escaping predators and surviving in various habitats, living either alone or in groups in nests or burrows. As prey animals, rabbits are constantly aware of their surroundings, having a wide field of vision and ears with high surface area to detect potential predators. The ears of a rabbit are essential for thermoregulation and contain a high density of blood vessels. The bone structure of a rabbit's hind legs, which is longer than that of the fore legs, allows for quick hopping, which is beneficial for escaping predators and can provide powerful kicks if captured. Rabbits are typically nocturnal and often sleep with their eyes open. They reproduce quickly, having short pregnancies, large litters of four to twelve kits, and no particular mating season; however, the mortality rate of rabbit embryos is high, and there exist several widespread diseases that affect rabbits, such as rabbit hemorrhagic disease and myxomatosis. In some regions, especially Australia, rabbits have caused ecological problems and are regarded as a pest.
Humans have used rabbits as livestock since at least the first century BC in ancient Rome, raising them for their meat, fur and wool. The various breeds of the European rabbit have been developed to suit each of these products; the practice of raising and breeding rabbits as livestock is known as cuniculture. Rabbits are seen in human culture globally, appearing as a symbol of fertility, cunning, and innocence in major religions, historical and contemporary art.

Terminology and etymology

The word rabbit derives from the Middle English rabet, a borrowing from the Walloon robète, which was a diminutive of the French or Middle Dutch robbe, a term of unknown origin. The term coney is a term for an adult rabbit used until the 18th century; rabbit once referred only to the young animals. More recently, the term kit or kitten has been used to refer to a young rabbit. The endearing word bunny is attested by the 1680s as a diminutive of bun, a term used in Scotland to refer to rabbits and squirrels.
Coney is derived from cuniculus, a Latin term referring to rabbits which has been in use from at least the first century BC in Hispania. The word cuniculus may originate from a diminutive form of the word for "dog" in the Celtic languages.
A group of rabbits is known as a colony, ''nest, or warren, though the latter term more commonly refers to where the rabbits live. A group of baby rabbits produced from a single mating is referred to as a litter and a group of domestic rabbits living together is sometimes called a herd.
A male rabbit is called a buck, as are male goats and deer, derived from the Old English bucca or bucc, meaning "he-goat" or "male deer", respectively. A female is called a doe'', derived from the Old English dā, related to dēon.

Taxonomy and evolution

Rabbits and hares were formerly classified in the order Rodentia until 1912, when they were moved into the order Lagomorpha. Since 1945, there has been support for the clade Glires that includes both rodents and lagomorphs, though the two groups have always been closely associated in taxonomy; fossil, DNA, and retrotransposon studies in the 2000s have solidified support for the clade. Studies in paleontology and molecular biology suggest that rodents and lagomorphs diverged at the start of the Tertiary.
The extant species of family Leporidae, of which there are more than 70, are contained within 11 genera, one of which is Lepus, the hares. There are 32 extant species within Lepus. The cladogram is from Matthee et al., 2004, based on nuclear and mitochondrial gene analysis.

Classification

The term rabbit is typically used for all Leporidae species, excluding the genus Lepus. Members of that genus are known as hares or jackrabbits.
Lepus species are precocial, born relatively mature and mobile with hair and good vision out in the open air, while rabbit species are altricial, born hairless and blind in burrows and buried nests. Hares are also generally larger than rabbits, and have longer pregnancies. Hares and some rabbits live relatively solitary lives above the ground in open grassy areas, interacting mainly during breeding season. Some rabbit species group together to reduce their chance of being preyed upon, and the European rabbit will form large social groups in burrows, which are grouped together to form warrens. Burrowing by hares varies by location, and is more prominent in younger members of the genus; many rabbit species that do not dig their own burrows will use the burrows of other animals.
Rabbits and hares have historically not occupied the same locations, and only became sympatric relatively recently; historic accounts describe antagonistic relationships between rabbits and hares, specifically between the European hare and European or cottontail rabbits, but scientific literature since 1956 has found no evidence of aggression or undue competition between rabbits and hares. When they appear in the same habitat, rabbits and hares can co-exist on similar diets. Hares will notably force other hare species out of an area to control resources, but are not territorial. When faced with predators, hares will escape by outrunning them, whereas rabbits, being smaller and less able to reach the high speeds of longer-legged hares, will try to seek cover.
Descendants of the European rabbit are commonly bred as livestock and kept as pets, whereas no hares have been domesticated, though populations have been introduced to non-native habitats for use as a food source. The breed known as the Belgian hare is actually a domestic rabbit which has been selectively bred to resemble a hare, most likely from Flemish Giant stock originally. Common names of hare and rabbit species may also be confused; "jackrabbits" refer to hares, and the hispid hare is a rabbit.

Domestication

Rabbits, specifically the European rabbit species, have long been domesticated. The European rabbit has been widely kept as livestock, starting in ancient Rome from at least the first century BC. Selective breeding, which began in the Middle Ages, has generated a wide variety of rabbit breeds, of which many are also kept as pets. Some strains of European rabbit have been bred specifically as research subjects, such as the New Zealand white.
As livestock, European rabbits are bred for their meat and fur. The earliest breeds were important sources of meat, and so were bred to be larger than wild rabbits at younger ages, but domestic rabbits in modern times range in size from dwarf to giant. Rabbit fur, produced as a byproduct of meat production but occasionally selected for as in the case of the Rex rabbit, can be found in a broad range of coat colors and patterns, some of which are produced via dyeing. Some breeds are raised for their wool, such as the Angora rabbit breeds; their fur is sheared, combed or plucked, and the fibers are spun into yarn.