Repellents to Reduce Cable Gnawing by Northern Pocket Gophers

Abstract

There is a continuing need to develop improved repellent formulations to protect buried cable installations fi-om damage by problem wildlife. We evaluated 2.0% mass/mass levels of capsaicin and denaton-i~~m benzoate in a polybutene carrier material (Indopol@) and an aboveground, rodent-deer plastic mesh barrier (\'exar@) for reducing gnawing by northern pocket gophers (Tho~not~lys talpnides) on communications cable (RG-8U). When treatments were applied as surface coatings, neither capsaicin nor denatonium samples were lower (P > 0.05) in measnres of cable damage compared to control (Indopol@ alone) or samples treated with \'exaP plastic mesh. When the test was repeated with a new group of 24 gophers ( n = G/group in each of 4 groups) bnt with the 2.0% capsaicin, 2.0% denatoniuin benzoate, and Indopol@ enclosed with electrical shrink tnbing, there was less damage for the capsaicin samples (P < 0.05) on mass, depth of cut, width, and volume of cable chewed when compared to samples treated with the Vexarm and Indopol@. Denatonium benzoate treatment also prodnced repellent effects ( P < 0.05) on the width measure when compared to Vexarm samples.In addition, the denatonium benzoate samples were damaged less than Indopol@ samples, although not significantly, as measnred by mass loss and depth of gnawing. Therefore, we concluded that although capsaicin and denatoneum benzoate appeared to be completely ineffective when applied as a surface coating to cable, the same agents became effective cable gnawing repellents when encased in electrical shrink tubing. This encasing procednre den~onstrated quite clearly that the means for applying the repellent agent are an all important aspect of de\.elopitlg effective prod~icts to control gnawing damage by northern pocket gophers. MANAGEMENT 63(4):1344-1349 JOURNAL OF WILDLIFE

Mortality of radio‐tracked wild rats in relation to transmitter weight and resilience of transmitters in relation to their design

“…In this case, we recommend using an antenna gauge of more than 0.3 mm and that at least the base of the antenna be protected by dental acrylic. If possible, the antenna cable should additionally be treated with a repellent but the efficiency of this protection depends on the manner in which the repellent is applied (Shumake et al 1999(Shumake et al ,2000 and still needs to be tested for whip antennae.…”

Repellents to Reduce Cable Gnawing by Wild Norway Rats

“…In a previous study using northern pocket gophers (Shumake et al 1999) the repellent effects of both capsaicin and denatonium on gnawing appeared stronger than those exhibited by wild Norway rats in the current study. capsaicin, for example, was shown to produce 95% less gnawing on all quantitative measures (volume, depth, width, and mass) when contained within the tubing over cable samples and compared to gnawing on placebo (control) cable samples.…”

“…As a result, they keep their incisors ground and sharpened. A few reports have been ~ublished dealing with gnawing in wild Norway rats and pocket gophers (Thomomys talpoides, Geomys bursarius) from the standpoint of cable damage (Howard 1953, Ramey and McCann 1997, Shumake et al 1999, but the objectives of most rodent control studies are to define their negative economic impacts and to recommend a means for ridding the premises of all rodents. Certainly, wild rats cannot be tolerated inside buildings for health and safety reasons, and reducing local populations remains the main method for dealing with this species.…”

“…One report (Welch 1954) described similar problems related to wild Norway rat gnawing behavior, protection of cables, and protection of food packaging materials. Recently, Shumake et al (1999) reported the development of an improved method for delivering chemical repellents to northern pocket gophers as they attempt to gnaw communications cable by using a plastic shrink tubing material for containing the chemicals. We evaluated the efficacy of 2 chemical repellents using plastic shrink tubing with wild Norway rats to deter their gnawing of communications cables in laboratory evaluations.…”

Evaluation of three repellents for the prevention of damage to olive seedlings by deer

“…This compound has been found to effectively reduce cable damage caused by gnawing of rats and gophers (Shumake et al 1999(Shumake et al , 2000. In contrast, there was no reduction of damage caused by northern pocket gophers (Thomoides talpoides) to coniferous nurseries (Witmer et al 1998).…”