Repellency of garlic extract to European starlings

Garlic and garlic oil were recently exempted from pesticide registration requirements, increasing the attractiveness of these substances as candidate vertebrate repellents. Because anecdotal evidence suggests that garlic may repel birds, the present experiment was designed to evaluate the aversiveness of garlic to European starlings (Sturnus vulgaris). Samples of feed were mixed with garlic oil to produce concentrations ranging from 1.0-0.1% (vol./mass). All garlic concentrations reduced consumption relative to consumption of untreated feed in two-cup choice tests (P < 0.05). These results are consistent with the possibility that garlic oil may be used to repel these birds.