I should clarify that del Hoyo & Collar are the chief editors of
"Illustrated Checklist of the Birds of the World. Vol. 1". Species accounts
for Cacatuidae were compiled by the late Ian Rowley. So it may have been Ian
who interpreted the findings of White et al. and this was accepted by the
editors.
Cheers,
Stephen
Stephen Ambrose
Ryde, NSW
-----Original Message-----
From: Mike Owen
Sent: Friday, January 8, 2016 12:57 PM
To: Perkins, Harvey; 'Stephen Ambrose';
Subject: Zanda? [SEC=UNOFFICIAL]
Interestingly the text of the White et al. paper gives a time of the
divergence of the two subgenera as 10.1 Ma while their Figure 2 gives it as
15.2 Ma. It isn't obvious from the text why this discrepancy occurs
- perhaps their supplementary data may help but I don't currently have that
available to check. The amount of time that has passed since two taxa
diverged is not in itself a basis of degree of separation - whether it be
species, subgenus, genus or family. It is the degree of generic difference
that is the key factor. Some taxa can rapidly diverge from each other while
others can remain little changed after the initial
divergence. To my mind the divergence of species within the
traditional Calyptorrhynchus is pretty small given it occurred at least
10 M if not 15 Ma. ago.
If del Hoyo & Collar want to elevate Zanda to full genus status I think they
have to be a bit more expansive in why than just saying than "DNA study
indicates that recognition is warranted", especially when the ones doing
that DNA work were happy to have it as a subgenus of Calyptorhynchus. My
suspicion would be that they misinterpreted the comments in White et al.
cheers,
Mike Owen
on Jan-16 10:30 AM, Perkins, Harvey wrote:
> The depth of the fork between the Calyptorhynchus and Zanda subgenera
(15.2 MY) in the White et al paper is deeper than that between Eolophus
(galah) and Callocepahalon (gang-gang) (12.4 MY), and that between those two
and the Cacatuine/Lophochroa lineage (14.6MY). I suspect that del Hoyo and
Collar interpreted this to mean that Calyptorhynchus should therefore be
split.
>
> Harvey
>
> Dr Harvey Perkins
> A/g Assistant Manager
> CRC Contracts, DFCTC & Legacy Programmes AusIndustry - Business
> Services
>
> Phone +61 2 6213 7472
> Internet: business.gov.au
>
>
>
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