I am a young French conservation and invasion ecologist who worked in the “Conservation Ecology and Biotic Interactions” team (IMBE Institute) led by Eric Vidal. From fall 2012 to fall 2016, I was based in New-Caledonia at the IRD (Research Institute for Development) research center where I completed my PhD thesis. My research focuses on the impacts and control of rats on tropical forest island ecosystems in New Caledonia. I am currently looking for a job or a postdoc in conservation ecology.
Invasive rats and native biodiversity in New Caledonian rainforests.
Insights for improvement of management strategies.
Insights for improvement of management strategies.
Introduced rats (Rattus spp.) are one of the major invasive species threatening native biodiversity on islands worldwide. Two species, the black rat (R. rattus) and the Pacific rat (R. exulans) are sympatric in New Caledonian rainforests, where questions as to the feasibility and the utility of their control (i.e. local limitation of their abundance) for the conservation of native biodiversity remain unanswered. In response to the lack of a conceptual framework for control projects, we first conducted a review of invasive rat control operations in island natural areas worldwide. Then we sought to characterize and understand the population dynamics of these two sympatric rat species and their interactions with native biodiversity in the rainforest of Mont Panié mountain. Lethal trapping operations and capture-mark-recapture showed that black rats were more abundant than Pacific rats. Diet analysis revealed that the two species consume both shared and unshared prey likely resulting in a strengthening and a broadening of their impacts on native biodiversity, relative to the impact that each species would have alone. Rats consume a large quantity of fruits and seeds, invertebrates, and Squamates. However, birds, which often justify the implementation of rat management projects, do not appear here to be one of their preferred prey, either as adults or through nest predation. A potential positive rat impact on seed dispersal was also highlighted through a comparison of seed germination after seeds had passed through rat versus native frugivore digestive tracts. Finally, we propose lethal trapping strategies to efficiently control invasive rat populations. A better understanding of both rat impacts in sympatric situations, and the link between rat density and the intensity of their effects on biodiversity would allow optimizing rat control strategies when eradication is not feasible.
