Journal of the Royal Society of Western Australia, 86:97-105, 2003 
Impact of rabbits on native bush remnants 
T J Lowe, S H Wheeler & L E Twigg 
Vertebrate Pest Research Section, Department of Agriculture, Western Australia 
100 Bougainvillea Avenue, Forrestfield WA 6058 
ISI tlowe@agric.wa.gov.au E ltwigg@agric.wa.gov.au 
(Manuscript received November 2002 ; accepted May 2003) 
Abstract 
The value of rabbit-proof fencing in protecting both bush remnants and agricultural production 
from the impact of rabbits was examined in remnants of coastal heath on two farming properties in 
southern Western Australia. The short- and longer-term effects of confining wild rabbits within 
these remnants were studied by excluding rabbits from, or confining them to, experimental sites. 
In the short-term (i.e. within 10-14 months), it was difficult to demonstrate an effect of rabbit 
grazing except that the percentage cover of sedges and native grasses was clearly reduced in the 
presence of rabbits. Other negative impacts only become obvious over the longer-term (>2 years) 
when the percentage cover of sedges and grasses, and the abundance of seedlings and regenerating 
plants, were reduced as a result of grazing by rabbits. This effect was more pronounced by year 2, 
suggesting that the impact of even a small number of rabbits would worsen with time. The impact 
of rabbits was greatest during periods of peak rabbit abundance. 
These findings strongly suggest that any residual rabbits within areas of fenced remnant 
vegetation must be removed prior to, or immediately after, fencing if the long-term viability of 
these bush remnants is to be maintained. If this could be achieved, then the use of rabbit-proof 
fencing to protect small areas of native vegetation from rabbits has some merit, particularly where 
the remnants have high conservation value. 
Key words: rabbit, Oryctolagus cuniculus, native bushland, fencing, exclusion 
Introduction 
European rabbits (Oryctolagus cuniculus) have had a 
devastating impact on both agricultural production and 
wildlife conservation in Australia (Cochrane & 
McDonald 1966; Cooke 1981, 1987; Williams et al. 1995). 
Rabbit-proof fencing has been used to varying extents 
over many years in Australia to protect agricultural 
enterprises from rabbit damage (Williams et al. 1995). 
However, its use for protecting areas of native vegetation 
from the detrimental impact of rabbits has received little 
attention. In Western Australia, areas of native vegetation 
on farms have been left uncleared, particularly where 
they are growing on ridges of light sandy soil which 
would otherwise be subject to wind erosion. This in turn 
has created a different problem, because such bush 
remnants provide ideal habitat for rabbits. Rabbits often 
attain relatively high numbers in these habitats, coming 
out to feed on, and often severely damaging, adjacent 
broad-acre crops and pastures. Although their impact on 
bush remnants in these circumstances is poorly 
documented, rabbits are believed to have a significant 
negative impact on this vegetation. Annual poisoning 
programs have been used to reduce the impact of rabbits 
on agricultural production in such situations (Williams et 
al. 1995), but this approach does not solve the problem on 
a long-term basis. Clearing the native vegetation is not 
an option because of the potential for soil erosion to 
occur, and also because of the need for conserving the 
remnant vegetation. 
© Royal Society of Western Australia 2003 
Intuitively, the use of rabbit-proof fencing to reduce 
the numbers of rabbits in bush remnants has merit. Such 
fences confine rabbits to areas with less nutritious food, 
decreasing rabbit productivity, and preventing 
immigration. Both these factors can result in reduced 
rabbit abundance within the fenced remnants. However, 
landcare professionals are often reticent in 
recommending rabbit-proof fencing because of the 
potential concern that any residual rabbits may cause an 
unacceptable level of damage to the bush remnants. This 
could occur either in the short-term when rabbit numbers 
may be relatively high immediately following the fence 
construction, or over the longer-term with continuous 
grazing by low numbers of rabbits. 
This paper addresses some of these issues, and 
examines whether (1) there were any short-term initial 
effects of confined rabbits on native bush remnants over 
the first year after enclosing a remnant with rabbit-proof 
fencing, and (2) there were any long-term effects on the 
vegetation (over >2 years) from a relatively low number 
of rabbits being confined within fenced bush remnants. 
We also comment on the benefits and costs of the 
construction of rabbit-proof fences for crop and pasture 
protection, and for the protection of bush remnants. 
Methods 
The study was undertaken in coastal mallee heath 
situated on two farming properties (Parsons' & 
Tomlinson's) near Boxwood Hill in southern Western 
Australia. Boxwood Hill is approximately 50 km due 
west of Bremer Bay. The sites used in the study had not 
97 
