Hummingbirds eat flies, along with a wide variety of other tiny insects and spiders. This meat-eating behavior is mandatory for their survival, providing nutrients that their sugary diet lacks. While hummingbirds rely on flower nectar, they cannot thrive on sugar alone. Insects are a critical component of their food intake, fulfilling nutritional requirements that the quick energy provided by sweets cannot.
The Essential Protein Source
Insects provide hummingbirds with complex nutrients absent in nectar, primarily protein, fats, and essential minerals. Protein is necessary for tissue repair, muscle maintenance, and new feather growth during molting. Fats and salts also support long-term sustenance and physiological health.
The need for protein skyrockets during the breeding season, especially for females and their rapidly developing young. Nestling hummingbirds require a diet almost entirely composed of protein-rich arthropods. The mother bird must consume and regurgitate hundreds of these small creatures daily to support the nestlings’ development of a skeletal system and full plumage. An adult hummingbird must consume dozens of insects daily to meet baseline nutritional needs.
Acquiring Flies and Other Small Arthropods
Hummingbirds actively hunt and consume an array of small arthropods, including gnats, aphids, mites, mosquitoes, and small spiders. They often target tiny flies, like fruit flies, which are attracted to fermenting fruit or sap wells. These prey items are precisely the right size for the birds to manage with their slender bills.
Hunting Strategies
They employ two distinct hunting strategies to capture these meals. The first is aerial hawking, which involves the hummingbird waiting on a perch, spotting a flying insect, and sallying out to catch the prey mid-air. Their incredible speed and aerial maneuverability, including the ability to fly backward, make them highly effective insect predators.
The second primary technique is gleaning, where the bird systematically plucks stationary insects or spiders from surfaces. Hummingbirds will hover to pick aphids from the underside of leaves and branches or extract small spiders from their webs. They also collect prey trapped in the sticky residue of tree sap, getting both a sugary drink and a protein snack.
Nectar and Sap: The High-Octane Fuel
While insects provide essential building blocks, nectar and tree sap deliver the massive energy hummingbirds require. These sugar sources are almost pure carbohydrates, fueling their high metabolic rate and sustained hovering flight. Hummingbirds must consume roughly their own body weight in nectar daily just to survive.
Flower nectar, or a sugar-water solution from a feeder, is rapidly digested and converted into energy for wing beats that can reach 80 times per second. When floral nectar is scarce, such as early in the spring migration, hummingbirds seek out tree sap. They often utilize small holes drilled into tree bark by Yellow-bellied Sapsuckers, accessing the sugary fluid that wells up inside.
These high-calorie liquids serve as the bird’s primary source of energy, but they contain almost no protein or fats. The complementary nature of their diet, balancing quick energy from sugar with complex nutrition from arthropods, allows these tiny birds to maintain their energetic lifestyle.