[Taxacom] Dispersal clarifications: frogs on an oceanic islands

[John Grehan]

bounces at mailman.nhm.ku.edu] On Behalf Of Jason Mate
Sent: Friday, June 10, 2011 8:05 PM

"In fact if you look at the faunas of oceanic islands you see some
groups, i.e. mammals, that are simply no good at it whereas others like
birds are."

The delineation of 'oceanic' island (as opposed to 'non-oceanic') is
another one of those prejudicial categories so often used in
dispersalist biogeography. As Heads has pointed out in the list and in
publications, supposedly oceanic islands can have non-oceanic life. The
lack of mammals and other "poor" dispersers may be a function of their
really being poor survivors in regions of highly unstable terrestrial
landscapes. 


Interestingly, the Pacific islands of Palau, 800 km east of the
Philippines and 1,200 north of New Guinea have only two bats as
terrestrial mammals and that would usually be ascribed to their superior
dispersal ability. Yet the islands have an endemic frog which appears to
be more closely related to a species in New Guinea than the Philippines.
The author of a study in 1997 naturally ascribed the origin of the Palau
species to island hopping (no pun intended) from New Guinea via
Halmahera. Must be a record for a frog jump.

John Grehan