The rabbit (Oryctolagus cuniculus) originates from the western Mediterranean. They were introduced to Britain by the Normans in the 12th century to provide meat and fur. They are now widespread throughout Britain and Ireland but are absent from Rum.
Rabbits can be found almost anywhere they can burrow. The most suitable areas are those where the burrow area and food supply adjoin. Open warrens are maintained where good burrowing conditions exist on areas of short grass, sand dunes and railway verges. They are rarely found above the tree line and avoid damp conditions and areas deep in conifer woodland. The random network of tunnels, dens and bolt holes is known as a warren. Tunnelling is undertaken predominantly by the female. The depth of the burrows depends on the nature of the soil and the height of the water table. Large warrens usually imply a high population.
Rabbits eat a wide range of plants including grasses, cereal crops, root vegetables and young shoots of meadow plants. They will also eat tree bark, especially when snow covers other food sources. They are normally nocturnal but will come out in daylight if undisturbed. Grazing by rabbits can be very beneficial to maintain the diversity of habitats such as chalk grassland, heathland and sand dunes. When rabbit numbers crashed following the introduction of myxomatosis into Britain in the early 1950’s, many grassland habitats changed to scrub with loss of associated wildlife such as the Large Blue butterfly (Phengaris arion).
Social groups vary from a single pair to up to thirty rabbits using the same warren. Within large groups there is a distinct social hierarchy. The most dominant males, known as bucks, have priority of access to the females, known as does. The most dominant does have access to the best nest sites. Bucks and does seldom fight with each other but competition between does for nest sites can lead to serious injuries and death. In groups with more than one female and more than one male rabbits are not monogamous. Lower ranking rabbits may be forced to breed in single entrance breeding ‘stops’ away from the main burrows where they and their young are more vulnerable to predators.
The breeding season is mainly from January to August, starting later in the North of Britain. Healthy females can produce one litter of 3-7 young per month during the season. The doe constructs a nest inside the burrow from grass bedding and lines it with soft fur from her chest and belly. The young, known as kittens, are born blind, deaf and almost hairless. Their eyes open at 10 days, they begin to appear at the burrow entrance at 18 days and are weaned at 21-25 days. Bucks are able to mate at 4 months, does at 3.5 months. They rarely live for more than 3 years with over 90% dying in the first year of life; most of these in the first three months. Young rabbits are preyed on by badgers, buzzards and weasels. Rabbits of all ages are taken by foxes, cats, stoats and polecats.
Rabbits have no legal protection in Britain and landowners are required to prevent them from damaging neighbouring land. In the middle of the 19th century rabbit numbers began to increase dramatically until they became major agricultural pests. Their increase was due to the large scale planting of hedgerows providing rabbits with shelter and the opportunity to burrow in loosened soil. New agricultural technology increased cereal production giving rabbits an easily accessible food supply. Large numbers of the rabbits natural predators were killed by gamekeepers on new shooting estates. During the war rabbit control methods were relaxed and numbers increased rapidly. By 1950 rabbits were destroying approximately £50 million worth of crops each year. In the early 1950’s the virus myxomatosis first occurred in Britain. The first record of a rabbit dying from the disease came in 1952 and within only two years 99% of the entire UK population had died. The disease has now become far less virulent and many rabbits are developing resistance, but outbreaks still occassionally occur. The rabbit has once again established itself as the major vertebrate pest of British agriculture, causing economic losses estimated to be in excess of £100 million annually (Natural England, 2011). Viral haemorrhagic disease (VHD) was found for the first time in wild rabbits in 1994. It is not yet widespread and the full implications are currently not known.