Being a lumper not a splitter from way back, and somewhat suspicious of
taxonomists in general (while benefitting from their hard work), I am not
competent to enter into arguments on species and subspecies.
(Incompetence, didn't stop me with common names, but that was more in the
spirit of good fun than science.) However, I'd like to comment on song
dialects.
Niels Poul Dreyer raised the possibility of song dialects being used
through playback to assess whether different populations would be likely to
interbreed. On 13 Aug 1998 he wrote:
"I have a tape recording of golden whistlers living on Fijii which differ
from Lord Howe and A. golden whislers. I would think other criteria for
splits should be isolation of populations, bird calls, hybridisation
possibilities. Would a male Golden Whistler on Fijii attract female
Australian Whistlers?. Maybe we should experiment by play back of tape
recording of another subspecies. Andrew Whittaker in Brazil could not
attract Scaly-backed Antbirds in Alta Floresta by using tape recordings
obtained of Scaly-backed Antbirds in
Ecurdor. On the ground the birds look very similar."
Many Australian bird species have geographical dialects in song, but some
caution would be necessary in interpretig the results of playback
experiments. In the breeding season, male lyrebirds are strongly
territorial and react very strongly to playback of the local territorial
song, but I remember the late Norman Robinson saying that a Tidbinbilla
Lyrebird (in the ACT) would not react to the very different song of a
lyrebird from Captain's Flat about 40 miles away. Yet the Tidbinbilla song
occurs again in Washpool National Park 800 km to the north. Vicki Powys
found 12 different songs within a 35 km radius of Sunny Corner (east of
Bathurst). Lyrebirds are a special case, I guess, but it does show that
caution is necessary.
Norman got me to play the territorial song of an Albert Lyrebird from Mt
Mistake in the territory of an Albert on Tamborine Mountain. The latter
completely ignored it and just went on singing. We played the local
Tamborine song, and he immediately stopped singing and came up to
challenge. One would have to conclude that he didn't recognise the Mt
Mistake song as lyrebird. But two weeks later when I played the Mt Mistake
song he reacted immediately. My guess is that hearing the local song
coming from the same spot and with the same 'tape-recorder' quality
immediately after the Mt Mistake song, he decided they were the same
'bird', and next time reacted accordingly.
I surmise that there are many clues apart from song, and that although a
male lyrebird might not recognise a song from another area, and therefore
probably the female would not do so either, if birds from the two
populations were put together they would very quickly recognise each other
as lyrebirds. And I suspect that the same would apply to other species.
Syd Curtis at Hawthorne
H Syd Curtis
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