The sittellas are a family, Neosittidae, of small passerine birds found only in Australasia. They resemble nuthatches, but whilst they were considered to be in that family for many years they are now afforded their own family. They do not migrate other than for local movements.
The sittellas are small woodland birds with thin pointed down-curved bills, which they use to extricate insects from bark. Nests are open cups in forked branches.
They were formerly classified in two separate genera with the Black Sittella in Daphoenositta and the Varied and Papuan Sittellas in Neositta. The two genera are now usually merged with Daphoenositta having priority.
The sittellas contain a single genus, Daphoenositta, which contains two species. The two species were once considered to be two genera, but when the two were lumped the genus name of the less well known Black Sittella was adopted (due to priority), while the family retained the family name based on the junior synonym (Neositta). The most common species, the Varied Sittella, was once thought to represent several separate species, including five species in Australia, but in spite of considerable variation in plumage there are extensive zones of hybridization where the forms overlap (including an area of Queensland where all five Australian species exist), and are now thought to be a single species with eleven subspecies. The Black Sittella has three recognized subspecies.
The two species of sittella are small passerines which resemble nuthatches in appearance. The wings are long and broad, and when spread have clearly fingered tips. The family has a generally weak flight, which may explain their inability to colonize suitable habitat on islands like Tasmania. The legs are short but they have long toes, but in spite of their lifestyle they show little adaptation towards climbing. They have short tails and are between 10-14 cm in length and 8-20 g in weight, with the Black Sittella tending to be slightly larger and heavier. The bill is dagger shaped in the case of the Black Sittella and slightly upturned in the Varied Sittella. The plumage of the Black Sittella is mostly black with a red face; that of the Varied Sittella is more complex, with the numerous subspecies having many variations on the theme. The sexes of some subspecies have entirely black heads, other white, and others dark crowns and paler throats. The backs of most subspecies are grey with darker wings, and the undersides are generally streaked or white. All sittellas exhibit some sexual dimorphism in plumage.
Sittellas forage on horizontal branches and the trunks of trees. Their foraging techniques has been described as hopping rapidly along the length of a horizontal branch, pausing briefly to peer for prey, occasionally hanging underneath the branch but usually on top of it. Most of the time is spent on branches rather than on the trunks. Birds on the trunks may travel upwards or downwards. Within the forest sittellas usually forage in the canopy. There are sexual differences in foraging, with males and females choosing to forage in slightly different microhabitats within the tree. Prey items are usually gleaned directly from the bark, although in a few instances sittellas will sally from the branch in order to snatch aerial prey. Having obtained prey sittellas will use their feet to hold it while they eat it, in a similar manner to parrots, and will also use their feet in order to hold back strips of bark in order to pry underneath it. There have even been isolated reports of tool use in some populations of sittellas. Sticks were used to pry boring beetle larvae out of cavities, in a similar fashion to that of tool using Woodpecker Finches of the Galapagos.
95% of the nests found in a study in New South Wales were in stringybarks, particularly the species Eucalyptus macrorhycha. The nests were almost always located high in the tree. Nest construction took around 7 days, but lining and decorating the nest added a few days to this. Nest building duties were shared amongst the group, and the speed of construction depended on how many birds were involved. Nests are usually placed in the prong of two branches, and is a deep cup decorated in the bark of the tree it is built in, thereby camouflaging it. Around 2-3 eggs are laid and incubated by the breeding female (or females if two are sharing the nest) for 19-20 days. Whilst incubating the breeding female is fed by the breeding male and helpers. After hatching the female broods the young for a few days, and for up to two weeks at night. The chicks are fed for 19-20 days in the nest. After fledging the chicks have a protracted period of parental care lasting up to 80 days, although 60 days is more usual.
Handbook of Birds of The World, Volume 12. Picathartes to Tits and Chickadees.(ORNITHOLOGICAL LITERATURE)(Book review)
Sep 01, 2008; HANDBOOK OF BIRDS OF THE WORLD, VOLUME 12. PICATHARTES TO TITS AND CHICKADEES. Edited by Josep del Hoyo, Andrew Elliott, and...