SUCROSE AVOIDANCE BY AMERICAN ROBINS (TURDUS-MIGRATORIUS) - IMPLICATIONS FOR CONTROL OF BIRD DAMAGE IN FRUIT CROPS

Altering the relative sugar content in fruit is a potential alternative to chemical, aural and visual repellents to control bird damage to cultivated fruit crops. Some frugivorous birds, such as the American robin (Turdus migratorius), lack the digestive enzyme sucrase, and therefore cannot digest sucrose. It was predicted that robins would avoid consumption of foods that contain sucrose. When offered sweetened agar cubes that contained glucose, fructose, sucrose, or a hexose mixture, total consumption was significantly lower and faecal sugar concentration higher in the sucrose tests. In tests involving two sugars, mean total consumption was reduced when sucrose was eaten. Development of high-sucrose fruits warrants further investigation as a means to mitigate bird damage to certain fruit crops.