MINT PLANT DERIVATIVES AS BLACKBIRD FEEDING DETERRENTS

Naturally occurring plant constituents are potentially useful as avian feeding deterrents. To a series of cage trials, pulegone, a compound found in various species of mint, suppressed consumption of rice seed by red-winged blackbirds (Agelaius phoeniceus) more effectively than m ethyl anthranilate. Furthermore, pennyroyal oil, from which pulegone i s obtained, was nearly as effective as pulegone itself. Brown-headed c owbirds (Molothrus ater) were more sensitive to pulegone than were red wings, but female boat-tailed grackles (Quiscalus major) were less sen sitive. Because pulegone produces both sensory irritation and post-ing estive distress, it has potential for seed treatment and other bird de terrent applications.