G'day! I was interested in your comments, Niels, on the Golden Whistler.
They could also be applied to the numerous forms of the Silver-eye in the
Pacific
I guess since it's become a bit of a free for all, I'll throw my 5 cents
worth in. I also have difficulty seeing on what basis it has been
determined that certain widespread island forms have been determined as
good species (eg the extensive variety of fantails and some types of
honeyeaters in the Solomon Is and adjacent groups) while the Island Thrush
(Turdus poliocephalus) has been considered one species with dozens of ssp -
most radically different from others in appearance, one race per island. In
Fiji alone there are at least 5 ssp, ranging from all jet black (ssp hades
on Ngau) to 2 shades of gray with chestnut abdomen (ssp layardi on Viti
Levu, Ovalau, Yasawa and Koro). As early as 1945 Ernst Mayr commented that
the five Fiji "races are as different as 5 species".
In New Caledonia, ssp xanthopus is sooty brown; on Lifu, ssp pritzbueri
(males) had head/throat creamy white, rest black (?extinct). Elsewhere
other variations...
As far as I can determine, there is no particular trend across the Pacific
with gradation of forms; some forms tend to be very similar in widely
scattered locations, while forms from adjacent islands as above may be
totally dissimilar. Some forms are mountain birds (Bougainville,
Kolombangara) while others are lowland (Rennell). Even the immatures vary
considerable. Bill colour varies, eyes...
By what principles were all these classified as ssp of one single species?
Interbreeding? It would have had to have been in captivity since the forms
are isolates. I have come across no record of such. And certainly DNA
testing was not available when this monospecific grouping was determined.
Nor have I heard if any DNA testing has been attempted on the group since.
Or is there an assumption that if a form varies from island to island they
must be local representatives of one species? If so, why the inconsistency
with other groupings (as mentioned above)?
Any thoughts? I find the Harry & Betty (and the late Barry) Albatross
debate descending a little into the ridiculous - since the identified forms
are just that - identifiable. I guess until the concept of a species is
more clearly defined we'll get more of the same.
Colin T. Richardson
80 Mingelo St, TOTTENHAM NSW 2873, Australia
Ph.+61-2-68924222
Email:
----------
> From: Niels Poul Dreyer <>
> To: David James <>
> Cc:
> Subject: Re: Golden Whistler Split
> Date: Thursday, 13 August 1998 9:46 pm
>
>
> Dear Folks
>
> I have followed the debate about albatross generic status and speciation.
It
> is very complicated stuff. Are the DNA different for Buller's Albatross
> nesting on Chatman Island from those breeding on Snares?. If so which id
> features are avialable and which one reach Australia.
>
> If we take the logic further I would guss there are lots of birds to be
> split. Has anybody thought about studying DNA and generic viability of
> Golden Whistlers on all pacific Islands. A LOT OF SPLITS IN WAITING I
have
> tape recording of golden whistlers living on Fijii which differ from Lord
> Howe and A golden whislers. I would think other creteria for splits
should
> be isolation of populations, bird calls, hybridasation possibilities.
Would
> a male Golden Whistler on Fijii attract female Australian Whistlers?.
Maybee
> we should experiement 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.
> Niels Poul Dreyer
> Niels Poul Dreyer
> 10/35-37 Denman Camp Road
> Scarness, Qld 4655
> Australia
> 61.7.41.248132
|
