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Why do birds migrate? Seasonal food scarcity finds study mongabay.com March 1, 2007 A new paper attempts to answer the age old question of why birds migrate. The authors, Dr. Alice Boyle and Dr. Courtney J. Conway of the University of Arizona, argue that birds are driven to fly long distances due to seasonal food scarcity. "It's not just whether you eat insects, fruit, nectar or candy bars or where you eat them -- it matters how reliable that food source is from day-to-day," said Boyle. "For example, some really long-distance migrants like arctic terns are not fruit-eaters." Their findings are based on computer analysis of 379 species of New World flycatchers from the suborder Tyranni, a group that includes kingbirds, flycatchers, phoebes, becards, manakins and cotingas. The researchers found that food scarcity was the most important factor in predicting the migratory behavior of a species.
Boyle and Conway found that forage in flocks are less likely to migrate. "Flocking can be an alternative way to deal with food shortages," explained Boyle, since a group of birds is more likely to find food than a lone individual. This article used quotes and information from a news release from the University of Arizona. Comments? News options News index | RSS | Add to MyYahoo! Advertisements: Organic Apparel from Patagonia | Insect-repelling clothing |
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