EVALUATION OF CINNAMAMIDE AS AN AVIAN REPELLENT - DETERMINATION OF A DOSE-RESPONSE CURVE

The dose-response curve was quantified for the avian repellency of cin namamide, a derivative of the plant secondary compound cinnamic acid, using a three-day, 'short-term no-choice' test. This test was designed to resemble more closely the availability of alternative food in the birds' natural environment than in previous no-choice studies. Cinnama mide reduced food consumption by feral pigeons (Columba livia Gmelin) at concentrations as low as 6.17 mu mole g(-1) food (0.09% w/w) and th is reduction increased with concentration. An R(50) index, the concent ration at which food consumption was reduced by 50% was interpolated f rom the dose-response curve as 18.4 (+/- 0.38) mu mole g(-1) food (0.2 6% w/w). This index can now be matched with those of related compounds in future structure-activity studies. The birds' response to cinnamam ide changed over the three-day trial with respect to concentration. Re pellency declined at concentrations < R(50) and increased at concentra tions > R(50). This suggests that pigeons become habituated to cinnama mide at low concentrations but at high concentrations they may develop a conditioned aversion. This study provides quantitative confirmation of previous laboratory and field demonstrations of cinnamamide's effe ctiveness as a non-lethal chemical repellent suitable for reducing avi an pest damage.