Ignorant hooded crows follow knowledgeable roost-mates to food: support for the information centre hypothesis

Communal roosting in birds may function to enhance foraging efficiency as e xplained hy tile information centre hypothesis. which predicts that success ful foragers return from the roost to the rewarding food patch and that bir ds ignorant of this food follow knowledgeable roost-males. We tested these predictions by exposing 34 radio-tagged, free-ranging, flock-living hooded crows (Corvus corone cornix) to a novel experimental set-up mimicking a sup erfluous food patch with maximum temporal and spatial unpredictability Each replicate lasted two days and M as located on a new site. Data were collec ted during ten replicates over three years. First, a crow was more likely t o visit the experimental food patch on the second day when it had been ther e on the first dal: Second, when a crow; had not been at this food patch on the first day; it Mas more likely to visit it on the second day if it had roosted together with a crow that had been there on the first day but only if this knowledgeable roost-mate returned to the food patch on the second d ay. Our results support the information centre hypothesis and suggest that communal roosting might function to enhance foraging efficiency in hooded c rows.