Nuthatches are small birds that are of the Passerine family known as Sittidae, and they belong to the genus of Sitta. These birds are most commonly found in the Northern regions. They breed well in temperate climatic conditions. However, it is seen that few of the species are also seen in the rocky and dry regions in Eurasia, and also there is a wide variety of species seen in the southern regions of Asia.
The Nuthatches are passerine birds and hence are very small and compact in appearance. These birds have very short legs and their wings are compressed. Their tails are seen to be square in shape and are having 12 feathers. These birds are known for their compact sizes and their bills may be red or yellow in colour, are long, pointed and very strong; also their toes are very sturdy and having long claws. The plumage of these birds varies among the different species. It is seen that most species are having backs that are blue- grey in colour and their underparts are white in colour. However, in some species the like in the Asian species, the birds have violet- blue backs; and the underparts of some other species are seen to be tinged with orange, lilac, rufous, or buff coloured feathers. The head is larger in proportion with the body and it is seen that the markings on the head varies among different species. However, it is noted that most of the species are having a long eye stripe that is black in colour and having a contrasting supercilium that is white in colour. The forehead is darkly coloured and the birds also have a blackish coloured cap. Though both the males and the females are similar in appearance, they may sometimes be distinguished by varying underpart colouration, particularly in the rear parts and the tail flanks. The young ones and the adults are also very similar in appearance and may be almost indistinguishable.
The Nuthatches are birds that are very vocal and they use sounds that are an assortment of trills, whistles and calls. The songs of the Nuthatches are very simple, including the breeding calls and songs. These calls are often very alike to their mates’ calls, although may be slightly longer in length. Also, most species produce similar alarm calls when they are threatened and hence can be recognized by the other species as well. It has been exclusively observed in the case of the Red-Breasted Nuthatch, that it can easily infer the detailed call variations of the Black- Capped Chickadee, and take appropriate precautions against predators.
The Nuthatches forage for food in almost the same way as the woodpeckers. They rely on their strong legs for support and are hence able to move vertically on the tree branches and trunks and search for food. They mostly feed on insects and other invertebrates, and may also feed on larger insects and snails, which are first wedged in the cracks on a tree and then pounded by the strong bill and eaten. They nest in cavities in trees or rock surfaces, building a nest that is lined by soft materials like moss, hair, and grass.