My 6th grade class was sitting on the floor in a large room facing a massive stone fireplace. I looked up attentively to the naturalist standing in front of our group. A small bird that I had never heard of was perched on her hand.
I don't remember much from that first raptor program I attended, but I clearly recall what happened when the naturalist shifted her hand back and forth, up and down. Like magic, the kestrel's head remained stationary while it's body bobbed with the naturalist's hand. My friends and I giggled wildly.
"The birds of prey presentation was pretty cool! ... They have a reflex, (I don't know what you call it) that their head can stay in the exact same spot - for diving."
--12-year-old Haley
The naturalist explained that this trick was actually pretty useful. If the bird was sitting on a branch waving in the breeze, she would need to keep her head still to maintain focus on her surroundings. This is also important for kestrels in particular with their ability to hover. While wings pump furiously, their eyes can stay locked on on their prey before diving in for the kill.
I later learned that this feat is called "gaze stabilization" and we can do it too! Try moving your head in different directions while reading this. You could probably still focus on my words because human eyes can swivel to stabilize our vision. Birds, on the other hand, have limited eye movement so they use their whole head to stabilize the view. This also gives them a more reliable image when pouncing or maneuvering at high speeds.
Now as a naturalist myself, I often find myself standing in front of a group with Aldo the Kestrel on my glove. I think back to the most memorable moment of my first raptor program and hope I can recreate that memory for the kids (and adults!) in my audience. Luckily Aldo is often ready to demonstrate and amaze with this fine stabilization skill.
Comentários