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Providing evidence to improve practice

Individual study: Effectiveness of deer repellents in Connecticut

Published source details

Ward J.S. & Williams S.C. (2010) Effectiveness of deer repellents in Connecticut. Human Wildlife Interactions, 4, 56-66


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 2006–2008 in two agricultural sites in Connecticut, USA (Ward & Williams 2010) found that 10 commercially available repellents varied in effectiveness at reducing white-tailed deer Odocoileus virginianus herbivory on trees. At one site, trees treated with Chew-Not®, Deer-Away® Big Game Repellent, Bobbex®, Liquid Fence® and Hinder® had greater needle mass (140–234 g) than did untreated trees (14 g). Needle mass of trees treated with five other repellents (Repellex®, Deer Solution®, coyote urine, Plantskydd® and Deer-Off ®) (23–81 g) did not differ from that of untreated trees. Trees treated with Bobbex®, and Hinder® were taller (35–36 cm) than untreated trees (25 cm). Tree height when treated with the eight other repellents (23–31 cm) did not differ significantly from that of untreated trees. At the second site, where herbivory was light, there were no significant differences in tree heights and needle mass was not measured. At each of two sites, two blocks were established in May 2006, each with 12 groups of six yew Taxus cuspidata trees. Each treatment was applied randomly to one tree group in each block. Additionally, one group was untreated and one fenced. Repellent application followed manufacturer instructions. Trees were harvested in April 2008.

(Summarised by Nick Littlewood)