Angry Bird

Recent HBS publication describes a Northern Cardinal using a tool in an act of aggression:

In the summer of 2023, HBS Associate Director Jason Love was in the Big Creek Ranger Station parking lot on the eastern side of Great Smoky Mountains National Park, getting his gear together for a 3-day backpacking trip on the Appalachian Trail as part of the Batpack project, when he noticed a male Northern Cardinal attacking its reflection in a car mirror. He watched for a bit, amused by the bird’s antics, when he noticed something peculiar: the bird picked up a piece of gravel and struck the mirror with an audible “clink”. He knew that birds like crows and ravens had been documented using tools in the wild, but he was pretty sure that this behavior had not been described in cardinals before. Fortunately, Rom Stanek, an undergraduate at North Carolina State University, was volunteering for the Batpacking project too and had a nice camera where he could record the behavior. He was able to record the bird’s behavior as it repeatedly picked up gravel to strike the window, in what appeared to be an act of aggression towards its competitor (which in this case was its reflection). Later Jason, Rom, and HBS research assistant Reagan Jarrett, who also witnessed the behavior, wrote up their findings and submitted it to The Wilson Journal of Ornithology, where it was published in December 2024.

1. Summer 2023

   A cardinal attacks its reflection in a car mirror at the Big Creek Ranger Station parking lot.

2. Then: “clink”

   The bird picks up gravel and strikes the mirror — again and again.

3. On camera

   Rom Stanek, volunteering on the Batpack project, records the behavior.

4. December 2024

   Jason, Rom, and Reagan Jarrett publish in The Wilson Journal of Ornithology.

The published figure

“You never know what you are going to see when you’re outside – that’s what makes the natural world so fascinating. We think the bird may have been frustrated that its competitor (its reflection) refused to be chased away, so the angry cardinal started using rocks to try and attack its reflection. We’ve already had a couple of ornithologists who specialize in bird behavior contact us from overseas about the paper, so it is already getting some interest” reported Jason. “You don’t need to be a scientist to observe these types of behaviors. Just get outside and take time to look around and observe. You might be surprised by what you see!”

Jason Love, HBS Associate Director

The Batpack project is funded by the Highlands Biological Foundation.