Human translocation as an alternative hypothesis to explain the presence of giant tortoises on remote islands in the south‐western Indian Ocean
2017
Giant
tortoisesare known from several remote islands in the Indian Ocean (IO). Our present understanding of ocean circulation patterns, the age of the islands, and the life history traits of giant
tortoisesmakes it difficult to comprehend how these animals arrived on such small, remote and geologically young (8–1.5 Ma) landmasses. For colonization to have occurred by dispersal, giant
tortoisesmust either have originated in Madagascar or Africa and swum for hundreds of km against the
ocean currents, or have launched themselves from the eastern IO margin and drifted with the currents over several thousands of km of open ocean. After these navigational feats, the
tortoiseswould have needed to found new, viable populations on potentially inhospitable volcanic or coral outcrops. Geologically recent sea level changes are likely to have eliminated terrestrial life from islands like Aldabra, complicating the scenario. We reviewed information relating to IO geology, the evolution and ecology of giant
tortoises, and the spread of humans within the region, and propose an alternative explanation: we posit that giant
tortoiseswere introduced to the IO islands by early Austronesian sailors, possibly to establish provisioning stations for their journeys, just as European sailors did in more recent historical times.
Keywords:
-
Correction
-
Source
-
Cite
-
Save
50
References
28
Citations
NaN
KQI