Research Projects

Tetiaroa is an atoll 50 km North from Tahiti. Managing most of this atoll, the Tetiaroa Society is conducting an ambitious restauration program of the atoll, aiming at bringing it back to a state close to the pre-human period. A key step of this program is the removal of high impact invasive species, including the black and Polynesian rats, and yellow crazy ants. The removal of these species also offers unique opportunities to track how the ecosystem responds to this manipulation.

This project is highly collaborative, as more than 12 (!) research teams from all over the World are investigating the impact of invasive species removal programs on Tetiaroa ecosystems (see the Tetiaroa Society’s website).

Yellow-crazy ants (Anoplolepis gracilipes) are present on several motus of Tetiaroa, and have reached very high densities on one of the most preserved ones, ‘A‘ie, where they already have obvious negative impacts on seabirds and invertebrate communities. Working with the Tetiaroa Society FP, we recently obtained the necessary funding from the OFB to eradicate this species from the atoll before it spreads more.

Listed as one of the 100 invasive species with the highest impact at the global level by the International Union for the Conservation of Nature (IUCN), the yellow crazy ant is now present on more than thirty islands in all four archipelagos of French Polynesia. To develop a better control of this invasive species in French Polynesia, we are researching the parameters explaining variation in yellow crazy ants density in Tetiaroa, while also investigating the ants’ impact on seabirds and land crabs. Miléna Philip joined the team in January 2022 to investigate these questions for her master project.
In collaboration with the Tetiaroa Society FP, we obtained a funding from the OFB (MobBiodiv Restauration) to attempt to eradicate the yellow-crazy ant from the atoll. Miléna was hired early August to organize this eradication. 

The terrestrial bird communities of French Polynesia are largely dominated by introduced species, to the point where, especially in Tahiti, most native species are difficult to observe while introduced species are part of the Polynesians’ daily life, being particularly common in anthropized areas. How native and introduced species interact remains however poorly understood and a global assessment of terrestrial bird community structures across habitats is needed to investigate the impacts of introduced birds on native species. Using over 350 point-counts and 50 transects distributed in six high islands and one atoll of the Society archipelago, we have been characterizing the structure of terrestrial bird communities in diverse habitats, along gradients of urban development and at diverse altitudes. Thanks to a grant from the Fondation Fyssen, we developed this project in June-July 2022 by conducting 300 point counts in four islands of the Australes archipelago, while also displaying audio recorders in different habitats to precisely characterize the song phenology of both native and introduced species (see our interview on local television : Polynésie la Première, TNTV). We will also expand the project to the Marquesas starting in 2022.

The characterization of these terrestrial bird communities will serve as background data to investigate the impact of specific introduced species on native birds, and to monitor changes across time by regularly conducting these surveys.

Some species appear to have a particular ability to establish successfully after a translocation event, and to adapt to their new environment. Similarly, the impact of urbanization varies substantially across species, and translocation success and adaptation to urban environments tend to be predicted by similar traits. The life history, genetic diversity, ecological niche width and behavioral plasticity of species are four components theoretically assumed to determine this establishment capacity and adaptation to urban environments, but their importance remains poorly understood. Using comparative analyzes, we aim at studying their relative importance in these different contexts (introduction success of exotic invasive species, translocation success for conservation purposes, and response to urbanization).

Using these same comparative analyses methods, we are also interested in responding to other global questions, including some with regards to bird diversification, the evolution of life history and behavior in vertebrates (and especially birds), and to the impact of variation in life history and behavioral strategies on species response to current global environmental changes.