[Taxacom] Woodpeckers, primates, as well as the Wallace Line gauntlet

[Michael Heads]

Hi Ken,
 
OK, that's honeyguides... Here's another one from pigeons I'd be keen to hear your views on:
 


   Columba: Widespread through the Old World from Africa to Samoa (including an endemic species on the Comoros), but not in Madagascar. 
   
   The sister group has two clades: Streptopelia s.s. (Stigmatopelia auctt.): Wide in the Old World, but not Madagascar etc., and Nesoenas: Madagascar, Comoros, Seychelles, Mascarenes, Diego Garcia. 
   
   Nesoenas and Columba overlap only in the Comoros and Mayotte, where both genera occur  on all four islands. (The Comoros are small but important for biogeography, e.g. the endemic passerine Humblotia).   
   So why doesn’t Columba occur in Madagascar? 
 
Michael 
 

Wellington, New Zealand.

My papers on biogeography are at: http://tiny.cc/RiUE0

--- On Sun, 22/5/11, Kenneth Kinman <kennethkinman at webtv.net> wrote:


From: Kenneth Kinman <kennethkinman at webtv.net>
Subject: Re: [Taxacom] Woodpeckers, primates, as well as the Wallace Line gauntlet
To: taxacom at mailman.nhm.ku.edu
Received: Sunday, 22 May, 2011, 4:40 PM


Hi Michael,
        Well first of all, my idea is that a lot of things could have
kept woodpeckers out of Madagascar.  I still maintain that they are not
great migrators compared to many passerines (or various other Orders)
that most likely got there first, and that woodpeckers may therefore
have not ever gotten there at all (much less tried to establish
themselves).   
        As for honeyguides, they apparently aren't migrators at all, and
stay very close to home.  They also have a very recent fossil record
(although that probably wouldn't impress you or John), and I wouldn't be
surprised if Picidae is paraphyletic with respect to them, and that they
arose relatively late.   
        They are also specialized in that they are nest parasites,
laying one egg at a time, and are rather particular in what species
nests they lay those eggs.  I hardly think they would easily establish
themselves on Madagascar, or even that any of them ever got to
Madagascar at all.  I'd give woodpeckers better odds of doing that (and
I obviously don't think much of those odds either).  I don't whether
call the honeyguide on Madagascar hypothesis "ad hoc" or grasping at
straws.   And I also wouldn't be surprised if Coraciformes is
paraphyletic with respect to Piciformes, and that the latter resulted
from dispersal and initial isolation, not vicariance.
       -------------- Goodnight,
                                   Ken   

-----------------------------------------------------------
Michael wrote:  
       I'm impressed with your idea that aye-ayes kept woodpeckers out
of Madagascar by invading the 'prying for grubs' niche first! But don't
forget it's all Piciformes that are absent from Madagascar, not just
woodpeckers. Other members, such as honeyguides (Indicatoridae), have a
very different ecology.   It would be nice to have a
simple explanation for the Piciformes absence from Madagascar
that also accounted for their absence from Australasia, and at
the same time explained the high level endemism of their
sister-group (Coraciiformes) in Madagascar and Australasia. If anyone
knows of any previous discussion of vicariance between the two
orders I'd be very interested to hear.       



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