Hi Michael,
The biogeography of a Tasmanian-New Zealand Morepork owl species is interesting
and complex, but I'm not convinced it is impossible. It may be unique as you
point out (from a Tas-NZ perspective), but that doesn't rule it out. But first
to the morphology.
The morphology has been discussed by Mees 1960s, Schodde & Mason 1980, 1997 and
Dunn 1999 (= HANZAB). They sort of agree but not completely, and I don't think
any of them got it exactly right. . When I looked at specimens recently (with
Murray) it was immediately apparent that NZ novaeseelandiae, Tas leucopsis and
Norfolk I undulata all cluster together as a morphological group. They differ
consistently from LHI albaria, Wet Tropics lurida, eastern boobook and arid
ocellata. The differences between the novaeseelandiae and boobook groups seem
to be greater than the differences within either group. That is the basis of a
significant difference between the two groups. I need to get a larger sample
size of specimens before I can describe the pattern fully, but for now here is
a summary: the novaeseelandiae group are smaller and have darker ground colour
below, characteristic fine spotting on the upperparts and bright yellow to
yellow-orange
eyes. Possibly this is convergent evolution. A paper by Norman et al. showed
a close genetic relationship between novaeseelandiae and undulata but not
leucopsis; however, it is an incomplete study and not particularly
enlightening.
If these 3 were a species apart from the mainland boobooks then what are the
plausible biogeographical scenarios?. Firstly, speciation (and subspeciation)
always works by one species becoming two (in a given space), when some form of
isolation occurs. So here are some scenarios. 1) The Aus owl evolved into 2
species, 1 on the mainland and 1 on Tas; the Tas species then colonised NZ and
NI (in whatever order and by whatever route) and diverged into 2 then 3
subspecies. 2) The Aus bird colonised NZ where it evolved into a new species,
and then recolonised Tas; problem is that it would then have to displace the
birds already in Tas on its return, and that seems unlikely. 3) The Aus bird
colonised NI, speciated, then invaded NZ and Tas (in what ever order), but
again colonisation of Tas with a resident Aus form seems unlikely. 4) It
radiated out of NZ and across Aus, but then you would not expect a change in
morphology between Tas and Aus and
between NI and LHI, and would have a problem explaining the diversity of small
ninox owls in Asia etc. There are some more unlikely scenarios. Only scenario 1
seems plausible to me.
Now, suppose they are all one species across Aus, Tas, NZ, LHI and NI with lots
of subspecies. The subspecies still have to evolve (1 becomes 2) through a
process of island biogeography and evolution. The only step that needs differ
from scenario 1 is that the owl did not need to speciate after colonising Tas
and before colonising NZ and NI. We know that many other birds have speciated
in Tas.
Fossil evidence would help test it, but Murray tells me he can't find much. A
thoughtful DNA would be able to test if the gap between Tas and Aus is larger
than the gaps between NZ, NI and Tas, and if the gap between LHI and NI is
larger than between NI and NZ.
As Murray said before, an Owl book by Weick considers the Red Boobook N.
lurida, of the Wet Tropics (not just Atherton) to be a full species. However,
the IOC does not agree for now, so it is not on the 'new aussie checklist' that
started these discussions. It is a distinctive-looking form, though the calls
are identical to my ears. But I am not convinced it is a valid species. I think
it hybridises with ocellata around Paluma, but the jury is still out on that
one. Here's the thing: it is not that hard to resolve the
species-or-subspecies issue when the breeding distributions abut. Lurida and
ocellata breed side by side in NQ with ocellata sort of surrounding lurida in
its rainfor enclave, Either they hybridise and are therefore subspecies or they
don't and are therefore species. Recent forest clearing may bl the picture, and
perhaps a small amount of hybridisation is hard to interpret, but there aren't
many data.
David James,
Sydney
==============================
________________________________
From: Michael Ramsey <>
To: ;
Sent: Thursday, 24 November 2011 8:13 AM
Subject: Re: [Birding-Aus] Grasswren and owl taxonomy
HI all, It does not seem to make sense, in a biogeographic sense that Tasmanian
and NZ Boobooks are the same species while mainland ones are another. I can't
think ofany other species pairs between Tas and NZ. Perhaps the birds share
some similar characteristics beacuse they inhabit wetter forests and more
southern forests than mainland birds. There is also the northern Atherton race,
lurida I think to consider as well. Would that be a seperate species too???
Michael> From:
> To:
> Date: Wed, 23 Nov 2011 19:12:25 +1100
> Subject: [Birding-Aus] Grasswren and owl taxonomy
>
> To address two points raised today:
>
> 1 Rowleyi form of Striated Grasswren. A 2010 paper on grasswrens by
> Christidis, Rheindt, Boles and Norman (Plumage patterns are good indicators
> of taxonomic diversity, but not of phylogenetic affinities, in Australian
> grasswrens Amytornis (Aves: Maluridae)) included genetic samples from
> rowleyi. While it didn’t specifically address whether it deserves to be
> split, some of the the results did suggest the genetic differences between
> rowleyi and other forms of Striated Grasswren are comparable with those
> between some other species pairs. Actually there have been quite a few
> papers on Fairy-Wren and Grasswren taxonomy in recent times. Most are listed
> at this thread on Bird Forums:
> http://www.birdforum.net/showthread.php?t=178345 ; It is interesting that this
> form was only described in 1999, whereas most of the other Australian splits
> or potential splits have been known about for a long time.
>
> 2 Tasmanian Boobook. This is something I have been looking at recently.
> The treatment Joshua refers to was first published in Handbook of the Birds
> of the World. At the time Les Christidis said (see
> http://bioacoustics.cse.unsw.edu.au/birding-aus/1999-10/msg00418.html ) that
> it was based on a misinterpretation of some of his research. But having
> looked at specimens, the Tasmanian birds do look more similar to New Zealand
> ones than mainland ones. See these photos I took of specimens at the
> Australian Museum: http://www.pbase.com/mklord/boobooks ; Frank Rheindt and
> James Eaton are doing some research on genetics of Ninox owls which hopefully
> will shed more light.
>
> The second edition of Owls of the World by Weick goes further and splits four
> Boobooks – Tasmanian, New Zealand, Australian and Red (lurida). The absence
> of any genetic samples of lurida, plus a lack of detailed research on how
> they interact with other forms of boobook, makes it hard to assess the merit
> of that treatment.
>
> Hope this helps.
>
> Murray Lord
> ===============================
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