Why Do Hummingbirds Fight So Much?

Anyone who has carefully observed a hummingbird flitting about a nectar feeder or a patch of flowers has likely seen it happen. One moment, the graceful aerialist is darting between bright blossoms, jittery but tranquil as it laps up sugary juices. Then, suddenly, all hell breaks loose when a second bird approaches. In a flurry of chittering, gorget-flaring, and dive-bombing, the featherweights duke it out. The furious bout lasts only a few seconds but is long enough to declare a loser and send them zipping away.

Such violent outbursts may be surprising given the minute size and delicate appearance of these dazzling birds, but there is good reason for their aggression—their sweet tooth, says Scott Weidensaul, an ornithologist and author who has studied and banded the winged gems. Hummingbirds are highly dependent on nectar, the sugar-loaded syrup that plants generate to entice pollinators into spreading the plant’s genes. It’s the rare food that provides enough energy to fuel a hummer’s constantly whirring wings and rapidly firing heart. 

“They’re burning such extraordinary amounts of energy,” says Weidensaul, noting that some species like the Blue-throated Mountain-Gem can reach heart rates of more than 1,200 beats per minute. “I can’t imagine they would be able to maintain the energetic output that they do without that sugar water.”

When the stakes are that high, it’s little wonder that hummingbirds are protective of their food. To make matters even more dire, nectar is often hard to come by. “There’s only so many flowers out there,” Weidensaul says, and each one provides a limited supply of sugar before needing time to generate more. “There’s a lot to be said if you can figure out a way to dominate that resource for yourself.” For hummingbirds, this means fiercely defending their territory.

When a territorial hummer spots an uninvited guest, it wastes little time persuading the interloper to move along. Some approaches that might appear less aggressive to human observers—displays where the defensive bird fans and flashes its tail at its opponent while vigorously chattering, for instance—are unambiguous signals to other hummingbirds: You are not welcome. Other threats, like plunge-dives, stabs, and grabs with the bill and feet, are unmistakably antagonistic. Adult males are typically the most vehement in their defense and will respond more swiftly and harshly to other adult males, but hummers of all ages, sexes, and species will defend food resources. When birds do come to blows, the hopeful challengers almost always defer, unwilling to risk the strain of a full-fledged fight.

Fights over flowers and their limited nectar make sense, but why are hummingbirds so prickly at feeders, where the food supply is practically endless? In short, because hummingbirds evolved with small portion sizes, not all-you-can-eat buffets. “Five or six hundred years ago, you didn’t have large areas of ornamental flowers, and you certainly didn’t have hummingbird feeders,” Weidensaul says. “They’ve got millions of years of evolution that tells them, ‘I need to fight to protect this food source.’” To hummingbirds, a nectar feeder is just another flower––a particularly plentiful one, perhaps, but one bound to be depleted before long.

There is no way to completely override a hummingbird’s protective instincts, but it is possible to encourage greater tolerance among the bejeweled birds. Hummers defend larger territories when there are few flowers and nectar is scarce, so planting native species will help foster a friendlier environment; explore options with Audubon’s native plant database. Weidensaul also notes that they will benefit from more than just the flowers. Since hummingbirds depend on the insects and arthropods found around all sorts of native plants to meet their other nutritional demands, he explains, “having that complexity of structure and diversity of plant species is going to provide a lot more food for the hummingbirds beyond what’s coming from the feeder.”

Another approach is to hang multiple feeders in widely spaced or otherwise hidden locations (for example, around the corner of a house), which prevents conflicts and ensures that every bird has plenty of food. You can also simply hang more feeders in one cluster. “If you get a bunch of feeders in one place, and a bunch of hummingbirds coming in to them, at some point, nobody can chase everyone away and they just kind of give up,” Weidensaul says. With enough nectar and a little luck, it may be possible to attract a whole charm of hummingbirds.

Audubon’s guide on how to create a hummingbird-friendly yard has plenty more tips to attract—and placate—the feisty fliers. Your actions might not prevent every tail-twitching, feather-flaring spat, but they will help satisfy the tiny birds’ enormous appetites and provide them with the food they need to thrive.