A male ruby-throated hummingbird defends a feeder against another hummingbird. Credit: Julia Bayly / BDN

Hummingbirds don’t like to share their food. Once a hummingbird has claimed a food source they will use whatever weapons are available to defend it. That’s why it’s not unusual to see two or more of these tiny birds swooping, dive bombing and flying straight at each other like a WWII aerial dogfight.

It’s all part of the hummingbird’s territorial behavior. While it’s rare for them to fight to the death, it’s not unusual for a hummingbird to end the summer minus a few feathers lost in battle.

“This is one of the hummingbird’s behaviors that really captures people’s imaginations,” said Doug Hitchcox, naturalist with Maine Audubon. “These are the smallest of all birds, but they seem to have the biggest attitudes.”

There is a lot of in-flight chasing and vocalizing when two or more hummingbirds start to squabble over a single food source, according to Hitchcox.

“They make this wonderful little chittering noise,” he said. “They are the most fragile little packages, so getting physical is a last resort but it does happen and there are some sad photos of hummingbirds that have impaled each other with their long beaks.”

Maine is home to only one hummingbird species — the ruby-throated. The male ruby-throated hummingbirds are famous for being territorial, according to Hitchcox. The bright, metallic green birds with the distinctive reflective red throated spend their winters in southern Mexico and as far south as Panama. In the summer they return to Maine gardens and feeders, where they immediately stake out a claim.

“It really comes down to food,” Hitchcox said. “When the males show up in the summer they are basically prioritizing the food availability.”

Not only are they looking for a steady food supply, but the males are also betting on the fact that females will be attracted to the same food source. But even when it comes to attracting a mate and breeding with her the male ruby-throated thinks with his stomach, according to Hitchcox.

“They are the worst fathers ever and take no part in raising the young and spend all their time defending their own food source,” Hitchcox said. “He’s really good at defending that food source to attract the female, but at a certain point he starts to drive the females away, too.”

And it doesn’t stop there. Male hummingbirds will try to drive off just about anything that it perceives going after its food, including larger birds and large moths.

“That can make it tough for the hummingbirds that are not the dominant male or the immatures just trying to find a place to eat,” Hitchcox said. “They find this nice buffett but as soon as they do find it, they get chased off by the dominant male.”

A male ruby-throated hummingbird will defend a perimeter about 50 feet from the center of his food source. That circle will shrink, according to Hitchox, the more food that is available inside of it. He said putting out feeders or planting gardens of native Maine flowers — many available from Maine Audubon — can help support more hummingbirds in an area.

Sometimes people confuse hummingbird mating displays with territorial behavior, Hitchcox said.

“It’s really quite elaborate with the female perched watching while the male does these deep, U-shaped dives flying down at her,” he said. “But that about all the energy the male puts into the mating process.”

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Julia Bayly

Julia Bayly is a reporter at the Bangor Daily News with a regular bi-weekly column. Julia has been a freelance travel writer/photographer since 2000.