[Taxacom] Woodpeckers: If any got to Madagascar, they were probably too late

[OConnor, Barry]

Given that the separation of Madagascar from Africa occurred long before the appearance of any of the orders of terrestrial mammals that now occur there, I think we can assume over-water dispersal as the source for those faunas. No one has done any phylogenetic work with the ticks and chiggers in Madagascar, which are presumably older and have species that parasitize "reptiles" that were possibly present in the area before the separation from Africa. Years ago Harry Hoogstraal, a major practitoner of the arm waving school of evolutionary scenarios, speculated on a possible relationship between some of the ticks that parasitize "reptiles" in Madagascar with species that occur in India. I've also intensively studied the mammal parasitizing mites in the Philippines. Exclusive of Palawan, which was connected to Borneo during the Pleistocene, and whose mammal fauna is very similar to that of Borneo, the ancestors of the mammals on all the other islands had to get there by over-water dispersal. In that case, the parasite faunas are very similar to those of the presumed mainland source region (Borneo, Sundaland, possibly Sulewesi); no lineages missing & only a few obvious host shifts. The difference between this fauna and that of Madagascar possibly relates to age and the distance over which the original dispersers had to travel; i.e. It was apparently much harder to get to Madagascar from Africa and survive.
All the best! - Barry

-So many mites, so little time!

Barry M. OConnor                    phone: 734-763-4354
Curator & Professor                 fax: 734-763-4080
Museum of Zoology                 e-mail: bmoc at umich.edu
University of Michigan
1109 Geddes Ave
Ann Arbor, MI 48109-1079

From: John Grehan <jgrehan at sciencebuff.org<mailto:jgrehan at sciencebuff.org>>
Date: Fri, 20 May 2011 09:21:32 -0400
To: "taxacom at mailman.nhm.ku.edu<mailto:taxacom at mailman.nhm.ku.edu>" <taxacom at mailman.nhm.ku.edu<mailto:taxacom at mailman.nhm.ku.edu>>
Subject: Re: [Taxacom] Woodpeckers: If any got to Madagascar, they were probably too late

That's a mitey (groan)interesting observation. The idea of 'depauperate'
or reduced diversity has often been represented as evidence of
colonization by a small number of founders. Of course that does not tell
you if those founders arrived, or were already present in Madagascar
before it separated from Africa, Australia, or India etc, but that
survived only in small numbers at some time, or that the reduction was
from some other factor.

John Grehan

-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu<mailto:taxacom-bounces at mailman.nhm.ku.edu>
[mailto:taxacom-bounces at mailman.nhm.ku.edu] On Behalf Of OConnor, Barry
Sent: Thursday, May 19, 2011 12:25 PM
To: Robin Leech; Richard Jensen; taxacom at mailman.nhm.ku.edu<mailto:taxacom at mailman.nhm.ku.edu>
Cc: Kenneth Kinman
Subject: Re: [Taxacom] Woodpeckers: If any got to Madagascar, they were
probably too late

I've studied the ectoparasitic mites of Madagascar mammals. Of the
specialist parasite groups (I.e. excluding ticks and chiggers), only
about half of the lineages that occur on mainland African hosts occur on
Madagascar. The mites of the Madagascar endemic rodents are related to
those of their African relatives (especially the Crictetomyinae), but
some lineages are absent. Of the mites of the tenrecs, one lineage is
shared with mainland Afrosoricida, but all the rest have relatives on
rodents. Of the primate mites, again, one lineage is shared with African
primates, but the others have rodent or perhaps tenrec relationships.
Madagascar carnivores have few mites, but those are shared with tenrecs.
Bats have a very typical bat-mite fauna with nothing missing or related
to non-bat mites. This indicates to me that for the terrestrial mammals,
there was a substantial founder effect with the original colonizing
individuals bringing only a subset of their associates. Those with
depauperate parasite faunas were perhaps more free to "accept"
colonizing parasites from other host groups that they would encounter on
Madagascar. I've studied mammal-mite communities in other insular areas,
but none are as unique as Madagascar.
With much hand-waving - Barry

-So many mites, so little time!

Barry M. OConnor                    phone: 734-763-4354
Curator & Professor                 fax: 734-763-4080
Museum of Zoology                 e-mail: bmoc at umich.edu<mailto:bmoc at umich.edu>
University of Michigan
1109 Geddes Ave
Ann Arbor, MI 48109-1079