Bird aversive properties of methyl anthranilate, yucca, Xanthoxylum, and their mixtures

We tested the bird aversive properties of methyl anthranilate, yucca extrac ts, and Xanthoxylum spp. extracts in one- and two-bottle drinking assays th at used European starlings (Sturnus vulgaris). In one- and two-bottle tests , methyl anthranilate proved to be the more potent stimulus in producing an avoidance response. Starlings avoided consuming Xanthoxylum and yucca only in the two-bottle tests. Previous studies showed that yucca was a good adj uvant in stabilizing lipophilic compounds in water. Starlings did not avoid binary mixtures of methyl anthranilate and yucca differently from what wou ld be expected if they were only responding to the solution's methyl anthra nilate content. However, yucca enhanced the aversive qualities of Xanthoxyl um. The ability to identify mode of action for repellency and synergistic c ombinations of chemicals derived from natural products for use in repellent mixtures is an important aspect of the development of cost-effective, envi ronmentally safe repellents for use in conflict resolution between humans a nd wildlife.