Repellency of Sucrose to Captive American Robins

Abstract

American robins (Turdus migratorius) are often pests of commercial fruit crops in North America. Because robins lack sucrase and cannot digest sucrose, they may develop an aversion to high-sucrose fruits. Thus, I tested captive robins with aqueous solutions of 15% (g/mL) mixed sugars (x% sucrose+y% glucose and fructose mixture = I5% sugar) to identify the level of sucrose required to develop a conditioned feeding aversion when digestible sugars are present. In 1-tube tests, robins decreased intake of 15% sucrose solutions 50% below baseline, but maintained stable intake of 3.75% and 7.5% sucrose solutions