Have you ever considered how many calories per day a hummingbird requires in order to survive? The answer may surprise you as it did me. According to the website Nectar Art Prints.Com, on an average 12 hour day, a hummingbird weighing 10 grams, such as a male Anna’s Hummingbird, will require a whopping 6,660 calories per day in order to survive. Wow, that is a lot of calories for such an extremely tiny bird! The hummingbird will expend more then 1/3 of that amount while hovering during their efforts to gather food.