tjwh
Apr 2, 2004 1:53 am
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Old World Rabbit
Geographic Range: Oryctolagus cuniculus, the European, Old World or Domestic rabbit, is the only species in its genus. The last Ice Age confined the species to the Iberian peninsula and small areas of France and northwest Africa, but due to human action and the rabbits’ own adaptability, the species today exists in the wild on every continent except Asia and Antarctica. Domesticated O. cuniculus are found worldwide. (Parker, 1990; Wilson & Reeder, 1993) **Habitat: Preferred habitat is dry areas near sea level with soft, sandy soil (for easy burrowing). Brushy fields are preferred for the cover they provide, but forests are also inhabited. Cultivated land was once well-suited, but this is no longer the case due to modern plowing techniques which destroy rabbit burrows. Particularly in central Europe, O. cuniculus has learned to coexist with humans in cities, making its home in parks and cemeteries as well as gardens and lawns. Human activities, particularly the spread of agriculture, have often inadvertently helped this species to colonize new areas. (Parker, 1990) **Physical Description: Wild O. cuniculus weigh between 1.5 and 2.5 kg, and is from 38-50 cm long. Domestic individuals may be larger. The coat is generally grayish, with black and brown (and sometimes red) sprinkled throughout. The underside of the body is paler gray, and the underside of the tail is white. Melanistic specimens are not unusual. (Macdonald, 1984) **This species (and rabbit species generally) have smaller ears and shorter, less powerful legs than their relatives, the hares. **This single species is the ancestor of all domestic rabbits (about 80 varieties!). Domesticated O. cuniculus vary tremendously in size, fur type, coloration, and general appearance. (Britannica, 1999; Nowak, 1997) **Reproduction: Rabbits are well-known for their reproductive capacity. O. cuniculus is capable of reproducing year-round, but most breeding activity takes place in the first half of the year. Gestation is about 30 days, and the average litter contains 5-6 young. Females experience postpartum estrus and thus may have several litters per year, though spontaneous abortions and resorption of embryos are common (possibly due to environmental or social stresses). (Vaughan, 2000; Nowak, 1997) One reason for the reproductive success of rabbits is induced ovulation, where eggs are only released in response to copulation. (Macdonald, 1984) Rabbit placentae allow an unusually high degree of contact between maternal and fetal bloodstreams, a condition they share with humans. Thus, they are useful models for the study of human pregnancy and fetal development. (Banks, 1989) The newborn young (kittens) are naked, blind and helpless. The mother visits the nest for only a few minutes each day to nurse them, but the milk is extremely rich. They are weaned at four weeks, attain sexual maturity at about eight months, and can live to nine years old. However, mortality rates in the first year of life fre |
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tjwh
Apr 2, 2004 1:56 am
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re: Old World Rabbit
...frequently exceed 90%. (Nowak, 1997; Macdonald, 1984) **Mating in rabbits is generally promiscuous, though males will attempt to monopolize particular females. Males take no part in the care of the young. (Macdonald, 1984) **Food Habits: O. cuniculus are generalized herbivores, eating a diverse diet of grasses, leaves, buds, tree bark, and roots. Gardeners know them to eat lettuce, cabbage, root vegetables, and grains. Their diet is relatively low in nutritional value, and high in indigestible material. However, O. cuniculus is one of several rabbit species that are known to reingest feces (coprophagy) to obtain extra nourishment from their food. The species has a very large caecum, in which bacterial fermentation of otherwise indigestible material occurs. Periodically, the contents of the caecum are defecated and reingested. They are thought to depend on this process for some essential nutrients, which are released or produced by bacteria and absorbed on this second pass through the digestive system. (Macdonald, 1984; Vaughan, 2000) **Economic Importance for Humans: Negative: O. cuniculus has been highly successful in most places where it has been introduced, and it is considered an agricultural pest in many areas (especially where its natural predators have been eliminated). They eat cultivated crops and compete with domestic animals for forage. Millions of dollars are spent annually in countries such as Australia, New Zealand, Britain and the United States in efforts to control, confine or exterminate them. Additionally, rabbits have inflicted enormous ecological damage in some areas where they have been introduced. **Economic Importance for Humans: Positive: The Old World rabbit is one of the most economically important mammal species. Wild O. cuniculus is a popular game animal, especially in Europe. Varieties of it are raised commercially for meat, skins and wool, and it is a popular pet. It is used extensively (.5 million/year) in medical research and for testing the safety of chemicals and consumer products. (Nowak, 1997; Banks, 1989) |
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tjwh
Apr 2, 2004 1:57 am
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re: Old World Rabbit
**Conservation Status: Few mammal species are farther from extinction than O. cuniculus. Not only is it valuable to humans as a domestic and game animal, but wild populations have established themselves successfully in many parts of the world. However, one variety of O. cuniculus found on islands in the Atlantic and Mediterranean may be at risk. (Wilson & Reeder, 1993) **Other Comments: Due to their popularity as a game animal and a food source, O. cuniculus have been introduced by humans widely around the world. They spread through much of the Mediterranean world in Roman times, and through much of Europe during the Middle Ages. Domestication and selective breeding have been practiced for over 1000 years. During the Age of Exploration, rabbits were left on hundreds of islands as a food source for later voyages, often with devastating consequences for island ecologies. (Nowak, 1997) **The introduction of O. cuniculus into Australia has created an ongoing ecological case study. The first rabbits were brought to Australia in the late 1700s, but the "invasion" really began around 1850. By 1900 O. cuniculus in Australia numbered an estimated 20 million. Its range, limited only by lack of water, spanned 1600 km. They became a serious threat to agriculture, primarily by competing for food with sheep and cattle. Therefore, extensive (and generally unsuccessful) efforts to control them were undertaken, including the large-scale use of poison baits. (Parker, 1990) A problem of secondary poisoning of rabbit predators (themselves introduced) has been documented. (Heyward & Norbury, 1999) **The economic costs to agriculture are dwarfed, however, by the ecological cost to the indigenous Australian flora and fauna. Many native mammal species are at a competitive disadvantage versus rabbits. A number of extinctions have been reported, with many other species in steep decline, though introduced predators have undoubtedly also played a role. Plant communities are also devastated by the voracious rabbits, and the denuded landscape is subject to increased erosion, further threatening native species through habitat destruction. (Parker, 1990; Nowak, 1997) |
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tjwh
Apr 2, 2004 1:58 am
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re: Old World Rabbit
**On the other hand, rabbits may provide some benefits to some native species. Their burrowing loosens soil, which can be advantageous for certain plant and animal species, and abandoned burrows provide ready-made shelters. (Parker, 1990) **A new chapter in the war against the rabbit began with the introduction of the disease myxomatosis into populations of O. cuniculus in the 1950s. Myxomatosis is caused by a virus endemic to South American rabbits, who have developed such a resistance that it has little effect on them. However, when European rabbits were first exposed to the virus, the effect was devastating. In some areas the rabbit population was virtually wiped out. Those rabbits that survived gradually became more resistant, but this immunity weakens over time in the absence of the virus. The result is that rabbit populations have been reduced, sometimes by more than 90%, and remaining populations are periodically ravaged by new epidemics of the virus. Myxomatosis has failed to eradicate the rabbits, as many had hoped, but it has greatly diminished their numbers. **Rabbits are preyed upon by a wide variety of carnivores, including canines, felines, mustelids, hawks and owls. (Britannica, 1999) |
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tjwh
Apr 2, 2004 2:00 am
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re: Old World Rabbit
From http://animaldiversity.ummz.umich.edu/ site/accounts/information/ Oryctolagus_cuniculus.html (remove spaces). Do a search at www.itis.usda.gov using "old world rabbit" to find more specific sites and photos regarding the Old World Rabbit. - Terry |
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bermoog
Apr 2, 2004 3:29 pm
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re: Old World Rabbit
Wow, that was a lot of reading! I learned a lot about rabbits. Thank you, Terry. I even had to lookup the definitions of a couple words, Melanistic and postpartum estrus. |
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tjwh
Apr 2, 2004 9:29 pm
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re: Old World Rabbit
It’s the magic of copy and paste, Rich. - Terry |
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