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Providing evidence to improve practice

Individual study: Anna’s hummingbirds Calypte anna rapidly learn to use feeders supplying sugar solution and may show a preference for red-dyed solutions in California, USA

Published source details

Wheeler T.G. (1980) Experiments in Feeding Behavior of the Anna Hummingbird. The Wilson Bulletin, 92, 53-62


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Provide supplementary food for hummingbirds to increase adult survival Bird Conservation

A controlled study in mountainous pine forests in California, USA, in July 1976 (Wheeler 1980) found that Anna’s hummingbirds Calypte anna fed more on red-dyed sugar solutions than solutions on other colours (17 visits/hour for red solution vs. 13 for yellow, eight for green, four for blue and five for uncoloured). However, birds did not show a preference when solutions were presented one after another. A separate experiment found that, after 40 minutes, approximately 80% of hummingbirds visiting a feeding area went to a feeder containing sugar solution, rather than a control feeder containing water. Solutions consisted of saturated solutions of cane sugar in water and were supplied from a 250 ml feeder with small holes near the base. The feeder had been used for several years before the experiment.