Response of Blackbirds (Turdus merula) and Silvereyes (Zosterops lateralis) to Geraniol and 2-Methoxy-3-isobutylpyrazine

Abstract

Grape aromas may be a cue to foraging birds in vineyards, and two typical grape aromas were offered in a controlled experiment to free-ranging blackbirds (Turdus merula) and silvereyes (Zosterops lateralis). Bird visits to a bird table with small nectar pots surrounded by a wick soaked in geraniol, a wick soaked in 2-methoxy-3-isobutylpyrazine (IBMP), and a wick soaked in an aromaless control were recorded and analyzed. Blackbirds stayed longer and drank more from the geraniol nectar than from the IBMP nectar and showed the least interest in the control. Silvereyes visited IBMP most but drank more and stayed longer at the control. It appears from these results that aroma may be a cue to some bird species that attack grapes.