REPELLENCY OF CINNAMIC ACID-ESTERS TO CAPTIVE RED-WINGED BLACKBIRDS

Each year, blackbirds cause millions of dollars of damage to newly planted rice in the southern United States. Currently, there is no product registered as a bird repellent rice seed treatment, so we conducted 2-cup feeding trials with individually caged male red-winged blackbirds (Agelaius phoeniceus) to test the repellency of methyl cinnamate and ethyl cinnamate, 2 naturally occurring esters of cinnamic acid. While ethyl cinnamate was moderately deterrent, consumption of treated rice was virtually eliminated by a 1.0% (g/g) application of methyl cinnamate. Additional effort should be given to understanding the chemical and physiological bases of repellency of feeding deterrents such as methyl cinnamate as well as to the development of these materials as bird management tools.