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Seabirds have been particularly affected by invasive alien species (IAS), which has led to the implementation of numerous eradication campaigns for the conservation of these keystone and highly vulnerable species. Although the benefits of IAS eradications for seabird conservation have been demonstrated, the recovery kinetics of different seabird populations on islands after eradication remains poorly evaluated. Here we present the results of an original long-term monitoring of the number of breeding pairs of seven seabird species on a small atoll, Surprise Island, New Caledonia (southwestern tropical Pacific). This long-term monitoring consists in a yearly core survey of the marine avifauna of the island conducted from 4 years before to 4 years after rodent eradication (conducted in 2005) combined with multiple one-time surveys from ∼10 years before and ∼15 years after eradication. This study was designed to evaluate how different seabird species responded to the eradication of invasive rodents in an insular environment. We found that three species responded positively to eradication with differences in lag-timing and sensitivity. The number of breeding pairs increased for two species in the four year post eradication due to immigration while one species showed a longer response time with an increase in pairs more than 10 years after eradication. Furthermore, we showed that long-term sampling is necessary to observe the responses of the seabird populations on the island. Our study confirms the positive effects of IAS eradication on seabirds and emphasizes both the importance of mid/long-term pre- and post-eradication surveys to decipher the mechanisms of seabird recovery and confirm the benefits of eradication for conservation purposes.

International audience; Even if there were problems with definitions of nativeness and non-nativeness, it would not at all affect the

James C. Russell,∗† Holly P. Jones,‡ Doug P. Armstrong,§ Franck Courchamp,∗∗ Peter J. Kappes,†† Philip J. Seddon,‡‡ Steffen Oppel,§§ Mark J. Rauzon,∗∗∗ Phil E. Cowan,††† Gerard Rocamora,† Piero Genovesi,‡‡‡ Elsa Bonnaud,∗∗ Bradford S. Keitt,§§§ Nick D. Holmes,§§§ and Bernie R. Tershy∗∗∗∗ ∗School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand, email j.russell@auckland.ac.nz †Island Biodiversity & Conservation Center, University of Seychelles, P.O. Box 1348, Anse Royale, Republic of Seychelles ‡Department of Biological Sciences and Institute for the Study of the Environment, Northern Illinois University, DeKalb, IL 60115, U.S.A. §Wildlife Ecology Group, Institute of Natural Resources, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand ∗∗Ecologie Systematique Evolution, Universite Paris-Sud, CNRS, AgroParisTech, Universite Paris-Saclay, 91400 Orsay, France ††Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife, Oregon State University, Corvallis, OR 97331, U.S.A. ‡‡Department of Zoology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand §§RSPB Centre for Conservation Science, Royal Society for the Protection of Birds, The Lodge, Sandy, Bedfordshire SG19 2DL, United Kingdom ∗∗∗Geography Department, Laney College, Oakland, CA 94607, U.S.A. †††Landcare Research, P.O. Box 69040, Lincoln 7640, New Zealand ‡‡‡Institute for Environmental Protection and Research, Via V. Brancati 48, Rome I-00144, Italy §§§Island Conservation, 2161 Delaware Avenue Suite A, Santa Cruz, CA 95060, U.S.A. ∗∗∗∗University of California Santa Cruz, 100 Shaffer Road, Santa Cruz, CA 95060, U.S.A.

Asclimaticallysuitablerangeprojectionsbecomeincreasinglyusedtoassessdistributionsofspecies, we recommend systematic assessments of the quality of habitat in addition to the classical binary classification of habitat. We devised a method to assess occurrence probability, captured by a climatic suitability index, through which we could determine variations in the quality of potential habitat. This relative risk assessment circumvents the use of an arbitrary suitability threshold. We illustrated our method with 2 case studies on invasive ant species. We estimated invasion potential of the destroyer ant (Monomorium destructor) and the European fire ant (Myrmica rubra) on a global scale currently and by 2080 with climate change. We found that 21.1% of the world's landmass currently has a suitable climate for the destroyer ant and 16% has a suitable climate for European fire ant. Our climatic suitability index showed that both ant species would benefit from climate change, but in different ways. The size of the potential distribution increased by 35.8% for the destroyer ant. Meanwhile, the total area of potential distribution remained the same for the European fire ant (>0.05%), but the level of climatic suitability within this range increased greatly and led to an improvement in habitat quality (i.e., of invasive species' establishment likelihood). Either through quantity or quality of suitable areas, both invasive ant species are likely to increase the extent of their invasion in the future, following global climate change. Our results show that species may increase their range if either more areas become suitable or if the available areas present improved suitability. Studies in which an arbitrary suitability threshold was used may overlook changes in area quality within climatically suitable areas and as a result reach incorrect predictions.