WHISTLERS & ALLIES Pachycephalidae
Whistlers, shrike-thrushes, shrike-tit, and allies
- 52 species in Australasia
- DR personal total: 24 species (46%), 4 photo'd
Pachycephalidae are a diverse family of landbirds within Australasia.
Genetic analysis is on-going, and the parameters of this family has
been very unstable in recent years. For example, Crested Shrike-tit
of Australia (left in a dramatic photo by Trevor Quested) is a
distinctive bird with isolated populations frequenting open woodlands
in east, southwest, and north Australia, has variously been considered
a pachycephalid or a member of its own family, the Falcunculidae
[Wattled Ploughbill Eulacestoma nigropectus of New Guinea has
sometimes been assigned as a close relative in that family's brief
existence]. The relationship of the shrike-tit was settled by Norman et
al. (2009); using nuclear DNA they found it to be sister lineage to the
core pachycephalids. So it is a whistler.
has the family level assignment been debatable, but whether Shrike-tit
is one species (as accepted by Sibley & Monroe 1990 and most field
guides, e.g., Simpson & Day 1996, Morcombe 2000) or three species
(adopted by Schodde & Mason 1999 and Dickinson 2003) is also an
open question. The three groups differ in size, back color, and
underpart pattern. In all three, males have black throats and females
olive-green. Our headline photo is of a female.
Although colorful, Crested Shrike-tits can be unobtrusive. Singles or
small family parties forage mostly high in the canopy and can be easily
overlooked unless their calls — a soft, piping, mournful whistle — are
learned [Simpson & Day 1996 suggest the pneumonic
'knock-at-the-door']. Sometimes their presence is revealed by the sound
of tearing bark. Morcombe (2000) writes: "The function of the heavily
built, deep bill is soon apparent if one of these birds is observed
foraging. Strong pieces of bark are levered up by sliding the bill
under, then rotating head and body to exert a twisting force through
the flat blade of the bill." In this manner hidden insects and grubs
The "core" pachycephalids are the genus Pachycephalus — 39 species of whistlers — and the genus Colluricincla,
7 species of shrike-thrushes. Norman et al. (2009) found that these
genera were paraphyletic. Two of the Pitohuis — Rusty Pitohui "P." ferrugineus and White-bellied Pitohui "P." incertus — should be moved to genus Pachycephalus, and so should the Morningbird of Palau, "Colluricincla" tenebrosa. Such changes would give us 42 species of Pachycephalus whistlers.
Pachycephalus whistlers are primarily forest birds in the mid or upper canopy, ranging from dull species to some bright ones, such as Golden Whistler
(right), a widespread bird of many subspecies across Australasia and
southwestern Oceania (this photo is from southwest Australia).
|Whistlers have adapted to a wide variety of woodlands. The two pitohuis just mentioned, plus Black Pitohui "P." [=Melanorectes] nigrescens, are birds of thick tropical jungles in New Guinea (the first two in steamy lowlands, the Black in montane cloud forests). Gilbert Whistler (left) is a specialty of dry gum eucalypt woodlands of southern Australia. Island Whistler P. phaionotus inhabits mangrove swamps in the Moluccas and west Papuan islands; Vogelkop Whistler P. meyeri
exists only in high montane forests in the Vogelkop Mountains on
western New Guinea. Quite a number of whistlers are local endemics to
remote mountains or south sea islands. This is a group that has
diverged and filled many niches across Australasia and southern
Many whistlers are much more easily heard than seen, and this can be especially true of the Colluricincla shrike-thrushes of Australia and New Guinea. Some are found in thick jungle; others, like Sandstone Shrike-Thrush C. woodwardi, are confined to arid sandstone cliffs in north-central Australia. The impressive vocalization of Grey Shrike-Thrush
(right) are a common sound in Australian woodlands, but getting views
(or photos!) can often be a challenge. This photo actually catches one
One of the most impressive attributes
of some whistlers is the presence of a poisonous toxin in their skin
and feathers. A powerful neurotoxin, chemically similar to that found
in Central American poison dart frogs, is present and has long been
known to native peoples in New Guinea, who avoid eating pitohuis.
Dumbacher et al. (2008) found that the presence of neurotoxic alkaloids
has evolved several times in New Guinea birds, and it may even be
widespread in corvoid birds (Jønsson et al. 2008). It appears
most potent in the true Pitohuis — Variable Pitohui P. kirhocephalus and Hooded Pitohui P. dichrous,
which now have proven to be closely related to Old World oriole
[Oriolidae]. They have evolved conspicuously orange-and-black plumage
as a warning, similar to patterns of colorful "warning" evolved in
Monarch butterflies. There are now questions as to whether other birds
have evolved Müllerian mimicry in response (Dumbacher &
The toxins come from eating poisonous melyrid beetles (Choresine),
and the toxins are stored in the skin and feathers. They have been
detected in Black "Pitohui" and in Rusty "Pitohui," which are not true
pitohuis but are whistlers; in Rufous Shrike-Thrush Colluricincla megarhyncha of New Guinea; and in Blue-capped Ifriti Ifrita kowaldi, a New Guinea endemic that is not within the whistler family (Dumbacher et al. 2008, Norman et al. 2009).
The full outlines of the Whistler family is not yet known. Some have recently thought Wattled Ploughbill Eulacestoma nigropectus
was closely related to Shrike-tit, and even separated out these two
genera as their own family Falcunculidae (Dickinson 2003) but the most
recent molecular evidence does not support this hypothesis (Norman et
al. 2009). Where the unique Wattled Ploughbill goes in the big scheme
of things is still not certain.
In contrast, the new evidence suggests that Crested Bellbird Oreoica gutturalis of Australia, plus Crested Pitohui "Pitohui" [=Ornorectes] cristatus and Rufous-naped Whistler Aleadryas rufinucha
are closely related and are not within the Pachycephalidae (Norman et
al. 2009). They are tentatively assigned to a new family, the
We now know that Mottled "Whistler" Rhagologus leucostigma
of New Guinea is not a whistler, but is within a clade that includes
woodswallows and African bush-shrikes, but its exact position is not
yet known (Norman et al. 2009). More dramatically, Olive-flanked
"Whistler" Hylocitrea bonensis of montane Sulawesi is not a
whistler, but is a member of the bombycillid radiation — it is related
to waxwings, Palmchat and Hypocolius (Spellman 2008) — and is current
best placed in its own family.
And then there are still mysteries. Is the unique New Zealand genus Mohoua
— the species Whitehead, Yellowhead, and Pipipi — among the whistlers?
Or should it be considered yet another new family? This is not
currently known. Norman et al. (2009) found Mohoua to "have
no obvious links to any pachycephaline genera" but beyond that the
relationships are muddy. The same goes for the New Guinea genus Daphoenositta (Pink-faced "Nuthatch"). There remains much to learn about the whistlers and their allies.
Photos: Trevor Quested photographed the Crested Shrike-tit Falcunculus frontatus on Mt Wilson, New South Wales, Australia in March 2004. The Golden Whistler Pachycephala pectoralis was in Dryandra Forest, Western Australia, on 4 Aug 2008. The Gilbert's Whistler Pachycephala inornata was on Gulpa Island, New South Wales, Australia, on 31 Dec 1997. The Gray Shrike-Thrush Colluricincla harmonica was at the Stirling Range Resort, Western Australia, on 11 Aug 2008. All photos © Don Roberson, except the Shrike-tit © Trevor Quested and used with permission; all rights reserved.
More photos by Trevor Quested can be seen on his website.
There is no "family book" covering the Pachycephalidae, but good
photographs and information about Australian and New Guinea species are
found in Frith (1979) and Coates (1990), respectively.
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.
Coates, B.J. 1990. The Birds of Papua New Guinea. Part II. Dove Publ., Ltd., Alderley, Australia.
E.C., ed. 2003. The Howard & Moore Complete Checklist of the Birds
of the World. 3d ed. Princeton Univ. Press, Princeton, N.J.
Dumbacher, J.P., K. Deiner, L. Thomposn, and R.C. Fleisher. 2008. Phylogeny of the avian genus Pitohui and the evolution of toxicity in birds. Molec. Phylog. Evolv. 49: 774–781.
J.P., and R.C. Fleischer. 2001. Phylogenetic evidence for colour
pattern convergence in toxic pitohuis. Müllerian mimicry in bird?
Proc. R. Soc. Lond. B 268: 1971–1976.
K.A., R.C.K. Bowie, J.A. Norman, L. Christidis, and J. Fjeldså.
2008. Polyphyletic origin of toxic Phiohui birds suggests widespread
occurrence of toxicity in corvoid birds. Biol. Lett. 4: 71–74.
H. J., consulting ed. 1979. The Reader's Digest Complete Book of
Australian Birds. 2d revised ed. Reader's Digest Services, Ltd., Sydney.
Morcombe, M. 2000. Field Guide to Australian Birds. Steve Parish Publ., Archerfield, Australia.
J.A., P.G.P. Ericson, K.A. Jønsson, J. Fjeldså, and L.
Christidis. 2009. A multi-gene phylogeny reveals novel relationships
for aberrant genera of Australo-Papuan core Corvoidea and polyphyly of
the Pachycephalidae and Psophodidae (Aves: Passeriformes). Molec.
Phylog. Evol. 52: 488-497.
Schodde, R., and I.J. Mason. 1999. Directory of Australian Birds. Passerines: i-x, 1-851. CSIRO Publishing, Canberra.
C.G., and J.E. Ahlquist. 1990. Phylogeny and Classification of Birds: A
Study in Molecular Evolution. Yale Univ. Press, New Haven, CT.
Sibley, C. G., and B.L. Monroe, Jr. 1990. Distribution and Taxonomy of Birds of the World. Yale Univ. Press, New Haven, CT.
Simpson, K., and N. Day 1996. Field Guide of the Birds of Australia. 5th ed. Viking, Victoria, Australia.
G.M., A. Cibois, R.G. Moyle, K. Winker, and F.K. Barker. 2008.
Clarifying the systematics of an enigmatic avian lineage: what is a
bombycillid? Molec. Phylog. Evol. 49: 1036-1040.