The latest evidence: This video from an Aussie videographer shows a large wedge-tailed eagle knock his camera-toting drone out of the sky.
The GoPro camera was knocked off the drone but survived the 50-foot fall, Lancaster said.
Commenters speculated on the YouTube video that the bird was defending her babies, though Lancaster said he saw no nest nearby.
"We found ourselves suddenly in a position where we were getting great footage of an eagle," he wrote. "We didn't really have long enough to think we're probably triggering her territorial instincts."
The eagle-drone clash comes four months after achimpanzee destroyed an invading drone at a Dutch Zoo.
That encounter cost the zoo $2,100. By comparison, the eagle only inflicted $31 damage on the Aussie drone, Lancaster said.
"I won't be flying the local seemingly 'safe' area anymore," Lancaster wrote.
According to the Australia Zoo, wedge-tailed eagles prey on rabbits, wallabies, small kangaroos, swamp birds and reptiles. We can now add drones to the list.
© 2015 CBS Interactive Inc. All Rights Reserved.