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Providing evidence to improve practice

Individual study: Evaluation of Hot Sauce® as a repellent for forest mammals

Published source details

Wagner K.K. & Nolte D.L. (2000) Evaluation of Hot Sauce® as a repellent for forest mammals. Wildlife Society Bulletin, 28, 76-83


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Use repellents that taste bad (‘contact repellents’) to deter crop or property damage by mammals to reduce human-wildlife conflict Terrestrial Mammal Conservation

A replicated, randomized, controlled study in 1997 on captive animals in a forested site in Washington, USA (Wagner & Nolte 2000) found that Hot Sauce® repellent reduced most measures of tree browsing by black-tailed deer Odocoileus hemionus columbi for four weeks, but not subsequently. There were fewer damaged trees in treated than in untreated plots during the first two weeks but not during the third and fourth weeks. There were fewer damaged terminal buds and lateral bites in treated than in untreated plots across all four weeks. There was no difference in the number of trees stripped of all leaves between treated and untreated plots on day one, but there fewer trees were stripped of all leaves in treated than untreated plots through to and including the fourth week. During weeks five and six, there were no differences in these measures between treated and untreated plots. Data were not presented. Three to four deer were held in each of four pens (0.75–2 ha). Two plots (>25 m apart) in each pen each contained three western red cedar Thuja plicata trees (0.5–1 m tall, 1 m apart). Plots were randomly assigned to a single application of 6.2% Hot Sauce® or were untreated. Tree damage was assessed between 4 February and 16 March 1997.

(Summarised by Nick Littlewood)

Use repellents that taste bad (‘contact repellents’) to deter crop or property damage by mammals to reduce human-wildlife conflict Terrestrial Mammal Conservation

A replicated, controlled study (year not stated) on captive animals in Washington, USA (Wagner & Nolte 2000) found that treating food with Hot Sauce® repellent (as a trial of its effectiveness at reducing crop consumption) reduced consumption by porcupines Erethizon dorsatum, reduced consumption by pocket gophers Thomomys mazama at two of four concentrations and did not reduce consumption by mountain beavers Aplodontia rufa. Porcupines consumed fewer treated than untreated apple pieces at all four Hot Sauce® concentrations. Pocket gopher consumption of apple pieces did not differ between treated and untreated food at 0.062% concentration. At 0.62%, fewer treated than untreated pieces were eaten on two of four days. At 3.1% and 6.2%, fewer treated than untreated pieces were eaten. Mountain beaver consumption of apple pieces did not differ between treated and untreated food at any of the four repellent concentrations. See paper for full details of results. Trials were carried out on four porcupines, 12 pocket gophers and 10 mountain beavers. All were held in enclosures and were offered two-choice tests between apple pieces treated with Hot Sauce®, a repellent containing capsaicin, and untreated apple pieces. Solutions containing 0.062%, 0.62%, 3.1% and 6.2% of Hot Sauce® were used. Each concentration was tested for four days with each animal. Tests ran consecutively, from lowest to highest concentrations of Hot Sauce® solution.

(Summarised by Nick Littlewood)

Use repellents that taste bad (‘contact repellents’) to deter crop or property damage by mammals to reduce human-wildlife conflict Terrestrial Mammal Conservation

A replicated, randomized, controlled study (year not stated) on captive animals in Washington, USA (Wagner & Nolte 2000) found that treating cottonwood Populus spp. stems with Hot Sauce® repellent reduced the extent to which they were chewed by beavers Castor canadensis. At all three Hot Sauce® concentrations applied, chewing damage was lower in treated stems than in untreated stems (results expressed as damage indices). Eight adult beavers were housed in pens that contained 1-m-long cottonwood stems of 7–10 cm diameter. Adjacent pairs of stems were randomly assigned for treatment by Hot Sauce® at 0.062%, 0.62% and 6.2% concentrations and untreated stems were available. Beavers also had free access to apples, carrots, pelleted food and water. The test was run for six days, then repeated. Damage to cottonwood stems was assessed at the end of each six-day period.

(Summarised by Nick Littlewood)