Thanks, birding-aus, for the heathwren advice.
On Aug. 21, I quoted Alec Chisholm as writing -
"But Australia contains at least twenty other diverse species of
birds which are highly skilled at vocal imitations, and one in particular,
a heathland sprite rather smaller than a sparrow, is relatively no less
accomplished than the lyrebird."
and I asked what was his "heathland sprite".
Thanks to the miracle that is e-mail, within a few hours I had the answer,
and this from the other side of the world: our antipodean friend Wim Vader,
of course.
My sincere thanks to Wim and all those who replied. Not only do I now know
that my old friend of years long gone was writing of the chestnut-rumped
heathwren _Hylacola pyrrhopygia_, but I've learnt other interesting things
as well.
Having been offered Heathwren or Hylacola, I consulted Christidis and Boles
and find that although the RAOU recommended English name had been Hylacola,
this proved unpopular and has been changed to Heathwren. ("Pacific @#
Baza" is popular???) So I was curious to see whether it had been Heathwren
before it became Hylacola, and yes, my 1946 edition of Caley gives it as
Heath-wren.
In 1976, the Reader's Digest bird book uses Hylacola ... but puts the
species in _Sericornis_. (Caley, like C&B uses _Hylacola_ as the genus.)
I was very interested to see the _Sericornis_, for I am familiar with _S.
citreogularis_ the Yellow-throated Scrubwren, as being a fine mimic.
Denyse Cusack and Michael Todd, gave me some useful references, and Michael
pointed out that the C.-r'd Heathwren weaves its imitations into its own
song. How birds use mimicry, is a fascinating subject and I urge anyone
who hears a bird mimicking to note carefully what is happening and to write
it up for publication or perhaps share it on birding-aus, as appropriate.
Consider the following:
# The two lyrebirds use mimicry as part of their breeding season song. I
think that many (most?) Australian bird mimics do not. The Toothbill
Bowerbird is another species that does ... and for the same purpose as the
lyrebirds, I surmise.
# A male Satin Bowerbird can keep up his continuous churring bower 'song'
and without interrupting, imitate a Lewin Honeyeater, presumably singing
the two sounds with the two sides of his syrinx.
# With lyrebirds the mimicry is passed down culturally from generation to
generation. They are not directly mimicking the other species, though
hearing the other species keeps their mimicry true to the models, and
originally each mimicked sound must have been copied from the model
species. (What about other bird mimics? Culturally learned or direct
copying of models?)
# The Rufous Scrubbird is a fine mimic ... but he mimics only as a
response to disturbance - which is the only way most people 'encounter' a
Scrubbird, so this is not particularly obvious.
# An Olive-backed Oriole that I was tape-recording in 1973 included some
Grey Butcherbird threat calls in its mimicry - and was chased vigorously
through the forest by a butcherbird. Does recognition by the model species
happen often? (A Spangled Drongo visiting my urban garden is a not
uncommon event often announced by mimicry of a Pied Butcherbird but I've
never seen any butcherbird react to it.)
Chisholm had revised his "at least twenty" up to 50 or so mimics by the
1960's and David Stewart tells me that the Audiowings tally of Australian
avian mimics is now up to about 70 species. There may be one near you. So
how about some observations, please.
Thanks again
Syd Curtis at Hawthorne, Q.
H Syd Curtis
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