Its a bird, it's a plane, it's a.... zygodactyl?
Updated: Feb 1
No, that's not a newly discovered dinosaur, it's a description of bird feet!
There are five different arrangements of bird feet that exist, and they all evolved to help birds exist in their respective habitats. Zygodactyl birds have two toes facing forward and two facing backwards, sort of like an 'X'. This arrangement is most common in birds who frequently climb trees, like woodpeckers because it helps them to grip and stay balanced on vertical surfaces. Many other birds including, including ospreys, have zygodactyl feet! Ospreys may not climb trees, but this specific arrangement of toes helps them firmly grasp the slippery fish they catch.
The most common type of bird foot is called Anisocactyl, and it has three toes at the front and one facing backwards. It is seen in songbirds and is adapted for perching. This toe arrangement works kind of like how our thumbs work when we are holding onto something!