Details of this species in Saint Helena Status: Alien
Invasiveness: Not specified
Occurrence: Established
Source: Ashmole and Ashmole, 2000 in Varnham, 2006 Arrival Date: 16th century, reintroduced in 1770
Introduction: Intentional Species Notes for this Location:
The rabbits present on St Helena are the subspecies Oryctolagus cuniculus huxleyi. They were originally introduced in early 1500, but were exterminated by feral cats and were reintroduced in 1770. They are now distributed across the entire island. Rabbit surveys estimate there to be between three and four rabbits per hectare and around 30,000 in total. Management Notes for this Location:
Control of rabbits on St Helena is complicated by interactions with other species on the island such as feral cats and rats. Thus control must be developed as an integrated programme for all three species to maintain the predator-prey balance, i.e. controlling just rabbits may lead to greater predation on endemic wirebirds. At present there is limited control being done which includes use of repellents, trapping/shooting and hunting.
It is also important to have full public support for any control methods carried out.
Bell and Boyle (2008) list the following as practical control methods for rabbits in St Helena:
- Warren destruction
- Trapping
- Fumigation
- Shooting
- Repellents
- Rabbit-proof fencing
- Disease (Rabbit calicivirus disease (RCD))
- Poisoning
Some of these options may be more effective and desirable than others. It is also important to have public support for any control programmes. The public attitude was relatively positive towards rabbits and many liked seeing them about and felt they had little negative effects. In general it was felt that that trapping and shooting rabbits was acceptable but poisoning or disease was not (Bell & Boyle, 2008).
Overall recommendations for control included an increase in traps purchased which would be supplied to local residents and businesses, intensive wider-scale trapping campaigns of rabbits (and feral cats; to maintain predator-prey balance), and encouragement of hunting through removing hunting restrictions in some areas and education. Rabbit proof fencing is recommended in some of the worst affected areas. Research into life history, breeding and behavior of rabbits on St Helena is strongly recommended. This information would enable long-term solutions such as poisoning or RCD to be investigated. Please follow this link for Management of rabbits (Oryctolagus cuniculus) on St Helena: a case study. Location Notes:
St Helena is an oceanic island 12,170 ha in size, located in the sub-tropical Atlantic ocean (Ashmole & Ashmole 2000 in Bell & Boyle 2008). The island is a self-governing British Overseas Territory with a governor appointed from Britain. St Helena is of high conservation value as it has a number of endemic plants and birds. However the introduction of invasive species such as livestock, rabbits, rats and cats have caused the extinction of at least six endemic plant species, and all but one of the endemic birds (wirebird remains) (Bell & Boyle 2008). St Helena is one of the five territories part of the European Union's South Atlantic Invasive Species Project (SAIS); a three year (2006-2009) project which aims at increasing these territories’ ability to deal with invasive species. Impacts:
Agricultural: Rabbits are an important agricultural and horticultural pest on St Helena. Farmers have reported almost total loss of crops by rabbit browsing (Bell & Boyle, 2008) and horticultural production at Longwood and Sandy Bay has suffered up to 100% losses of young plants. Rabbits also graze pasture which reduces food for sheep and other livestock (Miller, 2008).
Interaction with other invasive species: Rabbits have important predator-prey interactions with other invasive species on St Helena such as feral cats and rats. High rabbit numbers help maintain high predator numbers. Rabbit numbers are particularly high on two of the best habitats of the 'Critically Endangered (CR)' endemic wirebird (see Charadrius sanctaehelenae) on St Helena . As a result feral cats, which predate wirebirds, are also found in high numbers (Bell & Boyle 2008). Control of rabbits may result in prey switching of feral cats and rats to native species.
Reduction in native biodiversity: Rabbits threaten the five endemic plant species on St Helena through browsing, and are particularly damaging to young native plants growing in drier coastal zones (Miller 2008). Last Modified: 15/03/2010
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