U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Date of this Version

November 2001


Copyright 2001 Fiander Verlag.


Reforestation efforts are often severely hindered on sites that contain high populations of pocket gophers (Thmmysspp). Strychnine baiting is a technique used to suppress pocket gopher populations until seedlings are established. Strychnine bait is applied below ground in pocket gopher burrows, however, primary and secondary hazards remain a concern. A study to assess primary hazards indicated that some individual rodents died post strychnine baiting but there was not a long-term negative impact on non-target rodent populations. Possible secondary hazards reflect the potential for predators OT scavengers to encounter poisoned pocket gophers. Concerns that pocket gophers may surface before they succumb to the bait have been reduced through data acquired in pen trials. Most pocket gophers in trials with natural ground cover died in or near nest and all died below-ground. Carcasses of non-target species may pose some risk. These carcasses, however, are few and are thought to be consumed by insects within a few days. Trials are being conducted to evaluate the fate of these carcasses and to assess whether insects that feed on strychnine-containing carcasses pose a tertiary hazard.