Biology Reference
In-Depth Information
A
No. All owls have three toes that face forward and one that faces backward. You only
see two toes in front in perched owls because one of the forward toes is opposable, like
our thumb, and rotates to the rear when the owl sits on a branch.
Another bird of prey shares this feature — the Osprey. Osprey feet are specialized for
catching fish, with characteristic papilla called
spicules
covering the bottom of their feet.
Whentheygraspafish,thetwoalways-facing-forwardfronttoesarebalancedbytherear
toe and the opposable toe, making it harder for a thrashing fish to escape.
BaldEaglefeetlacksomeofthespecializationsofOspreyfeet.Whenaneaglecatches
a fish, its three forward toes from each foot grasp one side of the fish while the single
back toe from each foot grasps the other side. Eagle talons are powerfully strong with
long, sharp claws, but if a fish thrashes hard enough, it may pull out of the eagle's outer
toes, forcing the eagle to shift its grip. Sometimes at this point the eagle may drop the
fish. Eagles feed also on carrion and have a habit of stealing fish from Osprey, so despite
being a bit less specialized, they have a wider margin of error.
I often have the fun of speaking to classrooms about birds. Once after I explained
about eagles sometimes dropping their fish, a fifth-grade boy raised his hand and told me
about a wall-eye he had caught that summer. “The fish had six scars on one side of its
body, and two scars on the other, and I told my mom they looked like they came from
eagle claws. But she said I had a big imagination.” He was elated when I told him he'd
make a great forensic detective.
