Invasion Biology Introduced Species Summary Project

Introduced Species Summary P= roject
European Rabbit (Oryctolagus cuniculus)

Common Names: European Rabbit, Domestic Rabbit, Old World Rabbit

Scientific Name: Oryctolagus cuniculus

Classification:

= Phylum or Division: Chordata
Class: Mammalia<= /span>
Order: Lagomorph= a
Family: Leporidae

Identification: The European = rabbit is grayish brown with mixed black, brown and reddish hairs on its back, lig= ht brown to beige fur on its underside, a beige ring around its eyes, and long black-tipped ears. It ranges from 13.5 to 20 inches (34-50 cm) in length and has a small bushy tail that is 1.5 to 3.75 inches(4-8 cm) long. It ranges in weight from 2.25 to 5.5 lbs (1-2.5 kg), so it's a deceptively small and cuddly-looking little pest wherever it has been introduced by humans. Although the European rabbit looks like a rodent in m= any ways (the perpetually-growing incisors come to mind), it actually belongs to the order of lagomorphs, along with hares and pikas. Its natural predators are carnivores and birds of prey, but it has also been widely hunted by humans for sport, food, and its particularly soft fur. But along with the other lagomorphs, the European rabbit is a famously prolific breeder, which has turned it into a serious pest in the various areas where= it has been introduced, especially in Australia= . Females become sexually matu= re at only 3 months of age and, unlike most mammals, ovulate whenever triggered by copulation, rather than cyclically. Therefore they can produce litters as m= uch as 6 times a year, each litter ranging from 3 to 8 young (called kittens) a= fter a gestation period of only 28 to 33 days. European rabbits are ravenous eat= ers and indulge in a diverse diet of grasses, roots, tree bark, leaves, grains, fruit, seeds, and buds. Since this diet is low in nutritional value and hig= h in difficult-to-digest materials, they are known to reingest their feces to ob= tain extra nutritional value from the food the second time around. This double digestion process is called refection. European rabbits are social animals = and live in large communities in dry areas, grassland, some forests and near hu= man settlements. They dig burrows called warrens for protection and breeding and are mostly nocturnal. European rabbits have a lifespan of about 9 years.

Original Distribution: The European rabbit is the single common ancestor of all 80 or so varieties of domestic rabbits today. The last ice age confined it to the Iberian Peninsula and small areas of France and perhaps even Northwest Africa.

Current Distributi= on: Highly adaptable, the European rabbit now inhabits every continent except Asia and Antarctica= . It is widespread in Western = Europe including the Balearic Islands, Corsica, Sardinia, Sicily, and the British Isles; and Northwest Africa. It has recently been introduced to Southern South America; North America; <= st1:place>Australia= ; <= st1:place>New Zealand; and even, apparently, one Hawaiian Island. Of all these, it has been particularly detrimental to the Australian ecosystem.

Site and Date of Introduction: The European rabbit's introduc= tion to non-native areas is an historical phenomenon. The people originally responsible for its expansion were the Romans, who, having seen it in its native Iberian peninsula (which was then part of the Roman Empire), took it back to Italy for food. In 1066 the = Normans conquered England and introduced the rabbit the= re. Through the middle ages the rabbit kept spreading throughout Europe. During the age of exploratio= n it was brought to many islands by ship crews and wr= eaked havoc on the islands' small, limited ecosystems. But in a most devastating = blow for a continent, the European rabbit was introduced to Australia= in1859 by a rich British land= owner named Thomas Austin. Mr. Austin was living in <= span style=3D'font-size:10.0pt;font-family:Arial'>Winchelsea= , Victoria<= /st1:place> and missed the hunt from back= home. So innocently enough, he bought 24 rabbits and had them shipped to his esta= te in Australia. He set them loose on his gro= unds and proceeded to have some hunting fun.

Mode(s) of Introdu= ction: The European = rabbit was introduced to all of its present non-native habitats by humans, includi= ng the afore-mentioned Mr. Austin, who had his first 24 rabbits shipped to Victoria, = Australia, by boat. Unfortunately for t= he continent, there were males and females in this shipment.

Reason(s) Why it has Become Established: The European rabbit is a highly adaptable animal. It is = not a picky eater and breeds very fast. In Australia= , the rabbit was particularly = successful at spreading like wildfire because its natural predators from back home, the weasel and fox, were not originally present Down Under. The dingo and Tasma= nian wolf, Australia's native carnivores(and potential rabbit consumers), were themselves being kept in check by local sheep and cattle ranchers, so they = were not effective at keeping the rabbit populations down. The rabbits' spread w= as also aided by early hunters whose interest lay in having the animals spread= so they could hunt more of them.

Ecological Role: I= n its original habitat, the European rabbit's population was kept in check by its natural predators, so its role in the habitat balanced out with that of the other animals and plants. But in Australia= (and many small islands where= it has been introduced), the rabbit, virtually unchecked by local predators, decimates plants, affects soil composition, and changes entire ecosystems. = In Australia= , the rabbit competes for food= and shelter with native animals such as the wombat, the bilby, the burrowing bettong and the bandicoot, and therefore has contribu= ted to the decline of these native species.

Benefit(s): Australia has benefited very little fro= m the introduction of the European rabbit. The most important benefit is that tha= nks to the sheer quantity of rabbits, Australia= has made money from exporting canned rabbit meat and fur. And, let’s not forget a much less relevan= t, but pretty serendipitous bit: European rabbits were directly responsible, v= ia Aussie wit, for giving us the wonderful phrase "breeding like rabbits."

Threat(s): In Australia= , the European rabbit is a dow= nright pest. And because it has been an exotic introduction to the Australian ecosystem for over a century already, the threats it poses to the land have been well-documented and far outnumber the benefits. Few countries have been more ecologically and economically affected by a single introduced species. Because of its extremely high population--has fluctuated but has been belie= ved to reach almost a billion at one time--and indiscriminate eating habits, it= has continually decimated most of the local sheep and cattle's grass, turning o= nce-thriving sheep ranches into wastelands and thus at one point cutting wool production= in half. Many other plant species and competing animals have been driven to the brink of extinction by the rabbits' unstoppable appetite. Selective grazing= by the rabbits has changed whole ecosystems and has contributed to soil erosio= n. Also, the rabbit has been known to drive some smaller mammals (such as nati= ve mice) out of their burrows, helping foxes (also recently introduced to Australia= ) catch these smaller mammals,= hurting their populations. Native wildlife has also been hurt by the poison and tra= ps left out to catch the rabbits.

Control Level Diagnosis: "Highest Priority." The European rabbit continues to affect the Australian landscape and new methods to cull its numbers, such as immunocontraception, need to be further researched and then implemented.

Control Method: Several methods have been atte= mpted in the past 150 years. Shortly after its introduction in 1859 and subsequent population explosion within 50 years, bounty hunting of the European rabbit= was finally implemented. Hunters were given money for turning in rabbit tails a= nd millions were caught. poisoning and trapping were also common. In the early 1900s, the Australian government spent a million dollars to build a 2,000-m= ile long fence which kept the rabbits away from the cereal-growing southern reg= ions for a while, until a few got through the fence and started breeding again on the other side. In 1950 a virus that causes a mild illness called myxomytosis in Brazilian rabbits was found to be leth= al in European rabbits. The virus was promptly released into the wild in <= st1:country-region>Australia= and effectively spread like w= ildfire through mosquito and rabbit flea bites, and killed all but 0.2% of the rabb= its. This small percentage had built a resistance to the virus, bred like rabbit= s, and passed on the resistance to the virus. The population exploded again. In 1984 an outbreak of the Rabbit Hemorrhagic Disease (RHD), also known as Rab= bit Calicivirus Disease (RCD), was found in <= st1:country-region>China. By 1989 this had instigated Australian officials to investigate the possible use of this virus to once again cull the rabbit population. Researchers started conducting experiments with the virus in 1991, but in October 1995 a lab rabbit carrying the virus= got out and promptly spread the disease in the wild with devastating consequenc= es once again. The effects of this virus are still being felt in the European rabbit population in Australia= today. However, researchers h= ave not stopped there. They are currently investigating the possibility of controlling the rabbit population through birth rather than death. This new, biotechnological idea is called immunocontraception. It involves injecting a manufactured virus that fools the rabbit's body into thinking that certain proteins found on sperm and egg cells are foreign. The body's immune system would then produce antibodies that bond on to these proteins, which would prevent recognition between sperm and egg, preventing fertilization. Some of the rabbits would be purposefully infected with this manufactured virus, ma= te with other rabbits, and spread the immunodeficiency virus throughout the population, keeping it in check. This form of population control, unlike the previous forms, would be humane and not affect the rabbits' social structur= e.

References:
1. Smithsonian Institution AN= IMAL: The Definitive Visual Guide to the World's Wildlife. Editors-in-Chief David Burnie & Don E. Wilson. Dorling Kindersley Ltd.,2001.

2. The University of Michigan - Museum of Zoology - Animal Diversity Web - O= ryctolagus cuniculus. http://animaldiversity.ummz.umich.edu/accounts/oryctol= agus/o._cuniculus$narrative.html

3. Animalls.net -El Conejo Enano: Oryctolagus cuniculus. http://www.animalls.net/ARTIC73.HTML

4. Alien Species in Hawaii: European Rabbit - Status of = Oryctolagus cuniculus ssp. cuniculus (Leporidae) in the main Hawaiian Islands as of 05/98. h= ttp://www.hear.org/AlienSpeciesInHawaii/maps/OryCunCunV01HI.htm

5. Info on the European Rabbit. = http://ks.essortm= ent.com/europeanrabbit_rmoq.htm

6. Biodiversity and Conservation= : A Hypertext Book by Peter J. Bryant. Chapter 9: Exotic Introductions.<= br> http:/= /darwin.bio.uci.edu/~sustain/bio65/lec09/b65lec09.htm# Exoticsin Australia= and New Zealand

7. Economic and Ecological Impac= t of Rabbits - "BREEDING LIKE RABBITS": Control Of The Rabbit In Australia.http://rubens.anu.edu.au/student.projects/rabbits/home.html

8. Environmental Damage by Wild Rabbits in Australia and New Zealand, by Commonwealth Scientific a= nd Industrial Research Organization (CSIRO). http://beaglesunlimited.com/2001jul-aug/environmentaldamagebywil= drabbits.htm

9. "That Wascally Wabbit!", by Hope Bergemann, 2001. http://www.biology.iastat= e.edu/BiologyPages/Opportunities/intop/1Australia/Australia%20papers/Rabbit= s-H.%20Bergeman

10. Biotechnology Australia= : Case Study: European Rabbits= in Australia= . http://www.biotechnology.gov.au/biotechnolog= yOnline/environment/PestSpecies/e_EuropeanRabbit.htm

Photo credits:
1. Photograph of Oryctolagus c= uniculus taken from Animalls.net - El Conejo Enano: O= ryctolagus cuniculus. http://www.= animalls.net/ARTIC73.HTML

2. Map of "Present Distribu= tion of the Rabbit in Australia" taken from: Economic an= d Ecological Impact of Rabbits - History of the European Wild Rabbit in Australia= . htt= p://rubens.anu.edu.au/student.projects/rabbits/history.html

= Author: Flavia Schepmans
Last Edited: February17, 2003

| Project Home |