This Morning Outside
Toe of the Nuthatch
Fairfield, Iowa, October ~
How does the White-breasted Nuthatch walk upside down like that?
No doubt weighing only 2/3 of an ounce helps. There isn't much weight to cantilever out there. Still, most small birds can't pull off this feat.
Indeed, the feet are part of the nuthatch's special equipment. The nuthatch has a hook — the halux — the long toe that extends back, while the other three toes point forward. The bird sinks its backward toe-hook into irregularites in the bark, allowing it to take the next step without losing its grip. You can see the halux in this photo.
The long narrow bill looks something like a woodpecker's, and we often see nuthatches clinging to tree trunks. Maybe that's why people sometimes think that nuthatches actually are miniature woodpeckers. But nuthatches do not use their tails as kickstands against the tree. Their tails are quite short and not particularly strong. Furthermore, no North American woodpecker is as small as a nuthatch.
Nuthatches and woodpeckers do share the trunks of trees. Both find food insect life hidden in the bark. But strolling headfirst down the tree, the nuthatch sees the trunk from a different perspective and finds goodies that woodpeckers miss.
This White-breasted Nuthatch looks like a female, with the top of her head grayish rather than obsidian black.
— Diane Porter, Fairfield, Iowa, October 15, 2021