: Craig Moritz
, University of California Berkeley
Relative to other taxa, the vertebrates of Moorea are depauperate in terms of species
numbers, yet they are prominent, ecologically significant and represent an excellent group
with which to study the impacts of invasive species. In the pilot project, attention was
focused on the reptiles, which have been widely assumed to represent a wholly invasive
group, associated with both early Polynesian and subsequent European colonization. A Two 1 week sampling efforts provided population-level sampling of the most abundant species, including one (Hemidatylus frenatus) that has colonized and spread around the island's perimeter in the past decade and another (Phelsuma laticauda) even more recent entry. In collaboration with a local biologist, we also obtained sequences of 3foraging individuals of 2 marine turtle species from Moorea and other regions of French Polynesia; preliminary analyses of these are revealing new insights into distinct populations in the region. Sequencing of the Barcoding locus showed that genetic diversity does not predict invasion history, in that a presumed "native species" (Gehyra oceanica) had low diversity,some introduced species such as whereas the recently invasive H.frenatus haves very high diversity, similar to that across its native range in SE Asia, whereas other pre-European colonists (eg. the skinks) have low diversity. Analyses of the Mo’o’rea lizard (Gehyra oceanica) in collaboration with Robert Fisher (USGS) suggests that it might be two species on Moorea and elsewhere in FP, each of which has colonized from the western Pacific. We also found that foraging green turtles from Moorea (and other Society Islands) were genetically distinct from those in the Marquesas, and that the latter are possibly derived from Micronesian breeding populations. Finally, we developed a high sensitivity approach to genetically analyzing invasion dynamics for another species, Lepidodactylus lugubris, which has both diploid and triploid populations on Moorea.
This project will involve scientists from UCB and other institutions and a turtle biologist from
French Polynesia, thereby extending the intellectual and institutional reach of the MBP. The
bar-coding data will contribute to global databases, and for marine turtles, to Pacific-wide
conservation programs. More fundamentally, the results for reptiles and mammals will shed
light on current debates about the connection between genetic diversity and invasiveness
and on the role of human migrations in shaping biodiversity in the tropical Pacific. The
genotypic data for lizards will prompt further development of bioinformatics tools for
handling molecular data associated with field surveys and museum specimens.