Cottontail rabbits cause serious damage to ornamental plant production in Southern California. We used a 300-acre Southern California tree nursery as a cottontail CDFA vertebrate pest study site. We evaluated the relationship between nursery practices and the incidence of rabbit damage. GPS technology in combination with GIS software was employed to map and ascribe descriptive characteristics to the growing practices within each nursery bed. To understand the pattern of rabbit damage to irrigation, handheld GPS units were utilized by nursery staff conducting irrigation repair to assess damage caused by vertebrate pests. The waypoints taken by the irrigators superimposed on the map of the nursery had numerous benefits to the study, including demonstrating which growing conditions were most vulnerable to rabbit damage and elucidating if measures to reduce rabbit damage were successful. The same methodology may be helpful to researchers in many IPM fields.

Cottontail rabbits are a serious problem in Southern California. Of particular concern is the damage they do to ornamental plant and tree nurseries. Rabbit browsing reduces plant quality, kills containerized plants, and damages irrigation systems. Although anticoagulant baiting for cottontail rabbits is legal in California, growers should also consider multiple integrated tactics for rabbit damage control. This project employed GPS mapping technology to locate the occurrence of rabbit damage and correlate it with irrigation type, container, planting density, canopy width, and canopy height. GPS was also used to monitor the impact of experimental strategies to reduce rabbit damage. Strategies to reduce rabbit damage included the use of protective covers on irrigation tubing, exclusionary fencing, and trapping. Radiotelemetry was used to confirm the location of suspected rabbit harborages within the nursery. GPS results indicate that 1.27 to 1.9-cm (½ to ¾-in)-diameter irrigation line covers were effective in reducing rabbit damage to the irrigation system. Exclusionary fencing using erosion-control silt fencing acted as an excellent temporary barrier to protect individual growing areas and groups of planting beds, but it was found to be impractical for many nursery situations. Rabbit catch rates increased when traps were used in conjunction with drift fences. General tactics recommended to container nurseries based on these study results include: protecting and modifying irrigation systems, use of exclusionary fencing, trapping in conjunction with drift fencing, and modifying known rabbit harborages where possible.