Hummingbird feeders are a popular way to get close up views of some of the smallest and prettiest birds in The Americas. They also take the edge off of hummers having to find food multiple times each hour. But scientists have discovered the availability and use of feeders is causing an unusual change in some birds’ physiology.
Hummingbirds are known for their extreme need for regular food intake. When you rotate your wings 80 or more times per second, that uses up a lot of energy! Hummingbirds spend most of their waking hours searching for food. Back in the day, when flowers were the primary food source, food might be spotty, if not difficult to find – especially at certain times of the year, or if there had been a drought, or maybe your entire food bar had been torn down to make way for some agricultural fields or construction. Each species’ beak is adapted to certain types of flowers, so when those flowers weren’t available, there were no other options for food.
But with the proliferation of hummingbird feeders, where there is a lot more liquid energy readily available than in flowers, food sources in some areas have become more reliable. But competition for space at these feeders never seems to quit. As a result, scientists have found that some California hummingbird species, like Anna’s Hummingbirds, are rapidly evolving larger beaks, which helps them to scarf down more liquid at each feeder visit before the inevitable competitor chases them off. For more information, check out this Smithsonian Magazine article.