I was holidaying in Coorg with my family a few years ago, when on a lazy afternoon I spotted this curious bird that seemed to move in any direction on a tree trunk. I spent an hour watching the bird foraging on a few trees, flittering from one to another. I later learnt that it was a nuthatch. It was fascinating to watch it walk virtually in any direction on the tree trunks, sometimes upside down too!

A nuthatch is the only ‘upside down’ bird and can be identified by a typical pose shown here (of a female Indian Nuthatch).

A typical nuthatch pose

The word nuthatch comes from the original Middle English ‘nuthak’ which literally means nut hacker. This term refers to the way nuthatches secure a shell (by wedging it into the crevice of a tree) and then hammer away at it with their bills to get to the kernel.

Nuthatches are in fact omnivorous, feeding on insects, nuts and seeds. They forage for insects hidden in or under barks by climbing along tree trunks and branches. Their ability to walk upside down gives them visibility of insects that are missed by woodpeckers that only walk up on a tree trunk. They forage within their territories when breeding, but they may join mixed feeding flocks at other times. I recently watched the feeding frenzy of a mixed species flock of Indian Nuthatches, Velvet-fronted Nuthatches, Grey-capped Pygmy Woodpeckers, Ashy and Bronzed Drongos and Orange Minivets in the KGudi Wilderness Camp of JLR.

Indian Nuthatch with prey

While on the topic of food, it was interesting to learn that nuthatches are known for storing their food! The fact that they tend to store seeds and nuts for a rainy day makes them a good candidate for being territorial, which they are. They also don’t seem to forage very far from their territory for food.

There are around 28 different species of nuthatches in the world, out of which 9 are found in India, and two are found in Karnataka – Indian Nuthatch and Velvet-fronted Nuthatch.

Indian Nuthatch (Sitta castanea)

Like all nuthatches, a large head, short tail, and powerful bill and feet characterize an Indian Nuthatch. A pale white cheek patch contrasts with the dark reddish-chestnut underparts. The crown and nape are distinctly paler than the mantle. It is also sexually dimorphic with the female having much paler underparts. Indian Nuthatches are found in deciduous forests, village groves, roadside trees and sometimes in gardens.

Indian Nuthatch (male)

Indian Nuthatch (female)

Velvet-fronted Nuthatch (Sitta frontalis)

This bird is distinctive with strong violet-blue upperparts, black forehead, black-tipped red bill, startling yellow iris and eye-ring, and a lilac suffusion to ear-coverts and underparts. It is also sexually dimorphic, with the male having a black eye-stripe extending behind eye (lacking in female) with stronger lilac suffusion on underparts (more cinnamon, less lilac in female). It is a resident breeder of all types of woods, although open evergreen forest is the optimal habitat.

Velvet-fronted Nuthatch (male)

Velvet-fronted Nuthatch (female)

Nesting and Breeding

Nuthatches nest in tree holes, making a simple cup lined with soft materials like moss, fur and feathers, or grass, on which to rest eggs. They also plaster mud around the entrance hole for better protection. Nuthatches are monogamous. Here is an image of a velvet-fronted Nuthatch pair cleaning up a hole, either for nesting or storing food.

Nuthatches and Woodpeckers

I can’t help coming back to harp on the versatility of this bird on the bark! Nuthatches can be confused with woodpeckers because of they forage on tree barks, but they are not related. The nuthatches have long, straight beaks that are second in strength only to the woodpeckers, but they aren’t chisel-shaped and their owners do not have the strong necks and shockproof craniums that protect woodpeckers from concussions. Woodpeckers have stiff long tails that provide them balance and support as they climb up a tree trunk. But our nuthatch friends don’t just climb up, but can move in all directions on a tree trunk. So, they have only short and stubby tails.

Now to an interesting difference – their foot structure. Woodpeckers are zygodactyl with two toes in front and two in back, which helps them with their vertical movement on the tree trunk. But nuthatches have anisodactyl feet just like any other perching bird, with three toes in front and one in back. How do they manage to be so versatile on the bark? The nuthatch has long hallux and decurved claw that allows it to hang head-down, and the even-more-sharply curved front talons provide a secure grip on tree bark. Such feet, adapted for climbing, are said to be ‘scansorial’ – as opposed to, for example, “cursorial” (for running) or “fossorial” (for digging).

The next time you go birding in a wooded habitat, look for these fascinating birds. They will keep you engaged with their ability to move around effortlessly on the tree trunks!

References:

  1. RSPB Community article – Five facts you should know about nuthatches
    https://ww2.rspb.org.uk/community/ourwork/b/scotland/archive/2016/05/19/five-facts-you-should-know-about-nuthatches.aspx#6wloUQBku1ezuBQC.99
  2. Wikipedia article on Nuthatch – https://en.wikipedia.org/wiki/Nuthatch
  3. “Birds of the Indian Subcontinent” Second Edition by Richard Gimmett, Carol Inskipp, Tim Inskipp; Oxford University Press; 2011
  4. THIS WEEK at HILTON POND, 15-21 November 2007, Installment #380 – http://www.hiltonpond.org/ThisWeek071115.html