Birds
Nuthatch
Sitta · also called nuthatches
A nuthatch is the bird that breaks the rules of tree-climbing. Where a woodpecker or a treecreeper only ever shuffles upward, a nuthatch runs down the trunk head first, gripping the bark with its toes and finding food that the upward-climbers walk straight past. Give it a nut and it will wedge it in a crack and hack it open — which is exactly where the name comes from.
Overview
Nuthatches are the genus Sitta, about 28 species of small, stocky, sharp-billed birds of mature woodland across the Northern Hemisphere. They eat insects and spiders from bark in summer and switch to nuts and seeds in winter. They are year-round residents that hoard food rather than migrate.
Upside down
A nuthatch is the only bird that habitually climbs down a trunk head first, moving in jerky hops with one foot stretched up as an anchor. This lets it see into the tops of bark crevices that woodpeckers, always facing up, miss. To open a hard seed it jams it into the bark and hammers — nut-hack — holding it steady with its feet.
Nest doorways
Nuthatches nest in tree holes and shrink the entrance. The Eurasian nuthatch builds a hard mud rim around a too-wide hole; the North American white-breasted nuthatch smears crushed insects around it; the red-breasted nuthatch daubs it with sticky conifer resin and flies straight in without touching the sides.
Status
Least Concern — most species are common and several use gardens with old trees. The exceptions are montane-forest specialists: the Algerian nuthatch (Endangered) and several threatened Asian pine-forest species.
Nuthatch: common questions
Why do nuthatches climb down trees head first?
It gives them a feeding advantage. Woodpeckers and treecreepers always work up a trunk, bracing on a stiff tail, and they tend to probe into crevices from below. A nuthatch, coming down head first, sees the bark from the opposite angle and finds insects, spiders, and eggs tucked into the tops of crevices and under bark flakes that the upward-climbers overlook. It manages the descent not with a supportive tail but with very strong toes and claws, keeping one foot stretched up behind as an anchor while the other reaches down.
How did the nuthatch get its name?
From its habit of opening nuts. The word is a worn-down form of nut-hack or nut-hatch, meaning nut-hacker. The bird carries a nut or a large hard seed to a favourite spot, wedges it firmly into a bark crevice or a fork so it cannot move, and then strikes it repeatedly with its sharp, chisel-like bill until the shell splits. You can often hear the tapping before you see the bird. It uses the same technique on acorns, hazelnuts, and beech mast.
Do nuthatches really wall up their nest holes with mud?
The Eurasian nuthatch does. It nests in an old woodpecker hole or a natural cavity and, if the entrance is wider than it wants, it collects beakfuls of mud and sometimes dung and builds a smooth rim that narrows the opening to a tight circle just big enough to squeeze through. The mud dries rock hard and helps keep out larger birds, squirrels, and weasels. Some North American nuthatches take a different approach, smearing insects or sticky resin around the entrance instead of building with mud.
Will nuthatches come to a garden feeder?
Yes, readily, where they occur. Nuthatches are frequent and confident visitors to feeders holding sunflower seeds, peanuts, and suet or fat blocks, and they often briefly dominate smaller birds before flying off. A typical visit is quick, in that the bird lands, grabs a single seed, and carries it away to wedge and hammer, or to hide in bark for later, then returns. Putting food near mature trees, and providing a nest box with a small entrance hole, both make a garden more attractive to them.