Some time ago, Tony Palliser wrote about the Cicadabirds in the wet
tropics, pointing out that birds in dry country call differently from those
in the rainforests.
>From what I can remember, the birds in the top end, Cape York and the
rainforests of the wet tropics all have a similar song, consisting of
slowly repeated, clear whistles; very different to the faster, buzzy song
of southern birds. The two song types must come very close to one another.
I've also had them virtually together near Julatten and I've had southern
call types at other localities futher west, such as around Davies Ck. I
have never heard a southern bird call with a clear whistle, nor have I
heard a bird from the range and habitat of the whistling version call like
a southern bird. I think you can rule out any possibility that one bird
will give both songs, depending on the habitat it finds itself in. Although
I agree that in the south Cicadabirds are mainly in drier forest types than
rainforest, they are typically in the wetter sorts of drier forests and
it's not at all unusual to find them in rainforest near the edges.
The interesting thing is that if you look in Storr's handlist of Queensland
Birds, you will find that the subspecies he lists have quite different
boundaries to the song types!
Did you see any females? I have a vague recollection that maybe the females
look a bit different.
If these birds were in the USA they would have been split long ago!
By the way, talk to David Stewart (senior) about it, because I think you'll
find he's got some info on where these things occur.
PO Box 128
Olema CA 94950