Rabbits and hares
The European hare (Lepus europaeus occidentalis) was introduced into New Zealand in 1851. Similar to the European rabbit, which is in the same family but in a different genus, it is larger, has longer ears and forelegs, tends to stand more ‘upright’. They are more solitary animals that breed on the ground rather than in a burrow. They weigh from 2.5-7kg and are 48-75cm long, with a slightly longer tail. While they are regarded as a nuisance, they do not do the same damage to vegetation as rabbits.
The European rabbit (Oryctolagus cuniculus cuniculus), is a mammal native to Spain and Portugal. It was introduced into New Zealand in the early 1800s for hunting and food. Varying in colour from grey to brown, they are around 45cm long and weigh 1.5kg and have a short fluffy tail. The ears are long. They live in social groups and breed in burrows.
Both hares and rabbits do better in dryer, agricultural and open plains regions.
Why are they a problem?
Vegetation, including native plants, grazed by rabbits struggles and generally fails to recover.
Allowing rabbit populations to increase leads to an increase in cats and mustelids. Conversely, once the population has increased, if their numbers are reduced then cats and mustelids turn their attention to birds. This illustrates the complexity of managing predator guilds around braided rivers.
Where are they found?
The highest number are found in Central Otago, the McKenzie Basin, North Canterbury and Marlborough, however, this can change, depending on where control methods are being used.
- Biological control – Rabbit haemorrhagic disease (RHD), formerly known as rabbit calicivirus disease (RCD) was illegally introduced into New Zealand in 1997. While it was initially very effective, by 2007 rabbit numbers were increasing, although not to previous plague levels. See the Ministry for Primary Industries website for a full discussion and current updates.
- The Department of Conservation (DOC) and landowners must control rabbits on their lands wherever rabbit densities threaten to become a nuisance to neighbours or important ecological values are threatened. Because of the complex relationship with predator guilds, rabbit control alone is likely to have negative consequences on braided river fauna unless it is undertaken in conjunction with controlling other predatory mammals.