 Nuthatches
are a small family of tree-bark specialists found throughout the Holarctic.
The are well-known for their habit of foraging head downwards, searching
the bark on tree trunks and large limbs. They can easily cling upside down
as they search for insects, grubs, and seeds. It is a familiar posture,
as shown by this White-breasted Nuthatch (left). All the nuthatches
are similar in shape and behavior, and "once one is familiar with one species,
all the others will be instantly recognized as nuthatches" (Harrap &
Quinn 1995). Indeed, they are all assigned to a single genus (Sitta).
The body is small and compact. They have a sturdy, pointed bill and short
legs with strong toes and long claws. The feet are "scansorial," specially
adapted for climbing and clinging. Two species of rock nuthatches in Eurasia
feed in a similar fashion on rock faces.
In North America, White-breasted Nuthatch is a familiar bird. It clings to rough-barked trees from the eastern deciduous forest to the oak woodlands of California and up into the western mountains in yellow-pine forests. The species is primarily resident. In contrast, Red-breasted Nuthatch (below) summers in higher elevation coniferous forests and moves downslope in winter. In some years they stage very impressive winter flights into the lowlands and to the coast, where they often visit backyard feeders. This one (below) spent the winter feeding on sunflower seeds in our backyard on the Monterey Peninsula. But is some winters there are none here at all. |
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 In
North America, another set of nuthatches specialize in closed-cone pine
forests. Brown-headed Nuthatch Sitta pusilla lives among the loblolly pine
of the southeast, while Pygmy Nuthatch (right) thrives in the knobcone
and related pine forests out west. In California there is a population
in Monterey pine forests along the coast (the photographed bird is one
of them) and a montane population in the Sierra Nevada and Rocky Mountains.
These two populations have different calls. The ones on the coast sound
to me like telegraph operations: dit-it dit did-it dit dit, etc.
These nuthatches are quite small and have shorter bills used to pry among
the closed cones of the pines. The birds are often seen high in the canopy,
clinging to pine cones, and are restlessly on the move constantly in small
family groups.
All nuthatches nest in cavities, usually holes in trees. The Pygmy Nuthatches
in my back yard dig their own nest hole in the soft wood of dead pine trees.
They have a cooperative breeding strategy that includes the paired adults
and 1-3 young from previous broods (apparently young males; it is the young
females that disperse). Nests with helpers have better breeding success
than those without. The helpers join in feeding the young and defending
the nesting territory (Roberson & Tenney 1993, Harrap & Quinn 1995).
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The real center of nuthatch distribution is Asia, with 15 of the 25
species there. Quite a number are local and seldom photographed, including
White-cheeked
Nuthatch of western China (below left; race przewalskii) and
Sulphur-billed Nuthatch, endemic to the Philippines (below right).
The former has a curious distribution: a population in the western Himalayas
and the one in China (perhaps two species?). The latter forages in mixed
species flocks in montane and mid-elevation forests.
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| Some nuthatches have very restricted ranges: White-browed Nuthatch
S.
victoriae is found only in the Chin Hills of w. Burma; Corsican Nuthatch
S. whiteheadi is restricted to Corsica; and Algerian Nuthatch
S.
ledanti is known from only 4 sites in northeast Algeria. The Beautiful
Nuthatch S. formosa of northeast India, Burma, and s. China is rare
and little known. So although it is a small family, and found almost entirely
north of the Equator (some Indonesian populations of a couple species are
south of the Equator), it is not at all easy to find all of the nuthatches.
Fortunately, most have loud and diagnostic calls that makes locating them
easier.
Nuthatches are related to northern creepers (Certhidae) and (more distantly) the tits and chickadees (Paridae); see Barker et al. (2004), Dickinson (2003). Thus they will likely remain in their familiar position among these families in any future revised world checklist. |
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| Photos: The White-breasted Nuthatch
Sitta carolinensis was photographed at Lake Solano Park, Solano Co.,
California, on 15 Jan 2006. The Pygmy Nuthatch
S.
pygmaea was in my backyard in Pacific Grove, Monterey Co., California,
on 3 Apr 2005, as was the Red-breasted Nuthatch
S. canadensis the day before. The
White-cheeked
Nuthatch S. leucopsis was at Huzu, Qinghai Province,
China, on 14 June 2004. The
Sulphur-billed Nuthatch
S. oenochlamys was above Hamut, Sierra Madres, northern Luzon,
Philippines, on 3 Jan 2006. All photos © 2006 Don
Roberson; all rights reserved.
Bibliographic note Family book: Rating This is a solid addition to the family books in the Princeton series. The plates appear separately in the front. I found the artwork rather good in a "field guide" style (without much background) opposite summary pages which include small maps. The maps I looked at were quite good). Distinct races are nicely covered. The text cover identification, habitat, breeding biology (very summarized), relationships, and detailed plumage descriptions, plus references which (in contrast to other similar efforts) look reasonably extensive. I don't personally see the need for the detailed plumage descriptions since no book like this can hope to cover the complete range of variation, and they are very tedious to read, but it is the "style" of these family books. There are some helpful extra maps and sketches of plumage details scattered in the text.Other literature cited: Barker, F.K., A. Cibois, P. Schikler, J. Feinstein, and J. Cracraft. 2004. Phylogeny and diversification of the largest avian radiation. Proc. Nat. Acad. Sci. 101: 11040-11045.TOP |
