Submitted to: Office fo the Vice-President Finance and Operations, University of Victoria
Submitted by: LGL Limited; Environmental Research Associates July 24, 2008
Short of directly managing rabbit numbers by such means as lethal control, there are a number of measures that could be taken in an attempt to mitigate rabbit damage. It was not within the present scope of work to identify the full range of management options. Such an exercise should involve a literature review. Nevertheless, a few options based on observations made during the surveys are presented here for consideration. First, buildings that provided nesting habitat should be torn down, repaired, or modified such that habitat suitability for rabbit nesting and hiding is eliminated or greatly reduced. Second, conifers growing in areas with mowed grass and with branches that grow close to the ground should be pruned such that the lowest branches are > 1m (the higher the better) from the ground. This should reduce the cover value of those sites which tend to be in proximity to athletic fields and ornamental plantings – especially those in and around zones 15 and 17. Third, structural construction materials and equipment should be stored for brief periods only, or stored in such a way to minimize opportunities for rabbits to go beneath them. Fourth, the design of future buildings and associated landscaping should be done in conjunction with a biologist in order to address potential rabbit habitat issues. Finally, valuable assets such as athletic fields could be protected by properly maintained and permanent fencing (e.g., chain link or heavy-gauge galvanized livestock mesh) that is buried at least 30 cm (and flared outward subsurface) and inspected regularly for breaches. Gates would have to be self-closing and rabbit-proof. Note that the plastic mesh fencing presently placed around the field in Centennial Stadium is not functioning as a long-term solution there.
Direct animal control can be approached in at least two different ways: live-trapping and shooting. Each approach has pros and cons. Trapping may be more appealing from the viewpoint of public perception. Conversely, trapping will be fairly labour intensive and the chances of it being a successful method are less certain than shooting. Trapping may, however, be a necessary precursor to a shooting program in order to improve the defensibility of shooting as an appropriate means of population control.
Trapping would involve the live-capture of animals that would then be euthanized and properly disposed of off-campus. Standard Tomahawk/Havahart style traps could be placed under vegetative cover in the vicinity of rabbit concentrations. To improve capture rates, traps should be pre-baited for a few days with highly palatable foods (e.g., apple, grain). Traps should be set in the evening and checked the following morning. The ability of trapping to efficiently meet the objectives of population reduction should be assessed in a pilot area prior to initiating a trapping program over a broader area of the campus. Live-capture using hand-held fishing nets could also be attempted in areas where rabbits can be approached closely, but the effectiveness of this technique would likely diminish rapidly after the first few animals were caught.
Night-time shooting using a high-velocity .177 calibre air rifle with scope designed for low-light conditions, is an efficient way to cull rabbits. The use of a firearm on campus would require approval from, and up-to date communications with, security and law-enforcement authorities. Although operations would be conducted at night and air rifles are reasonably quiet, illumination (street, parking lot, security, athletic field) plus the fact that the project is in an urban environment would enhance the chances that one or more members of the general public would observe and report the shooter. Carcasses would be properly disposed of off-campus.
