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Leptospirosis, an environmental infectious disease of bacterial origin, is the infectious disease with the highest associated mortality in Seychelles. In small island territories, the occurrence of the disease is spatially heterogeneous and a better understanding of the environmental factors that contribute to the presence of the bacteria would help implement targeted control. The present study aimed at identifying the main environmental parameters correlated with animal reservoirs distribution and Leptospira infection in order to delineate habitats with highest prevalence. We used a previously published dataset produced from a large collection of rodents trapped during the dry and wet seasons in most habitats of Mah&eacute, the main island of Seychelles. A land use/land cover analysis was realized in order to describe the various environments using SPOT-5 images by remote sensing (object-based image analysis). At each sampling site, landscape indices were calculated and combined with other geographical parameters together with rainfall records to be used in a multivariate statistical analysis. Several environmental factors were found to be associated with the carriage of leptospires in Rattus rattus and Rattus norvegicus, namely low elevations, fragmented landscapes, the proximity of urbanized areas, an increased distance from forests and, above all, increased precipitation in the three months preceding trapping. The analysis indicated that Leptospira renal carriage could be predicted using the species identification and a description of landscape fragmentation and rainfall, with infection prevalence being positively correlated with these two environmental variables. This model may help decision makers in implementing policies affecting urban landscapes and/or in balancing conservation efforts when designing pest control strategies that should also aim at reducing human contact with Leptospira-laden rats while limiting their impact on the autochthonous fauna.

Seabirds are among the most threatened groups of birds, and predation by invasive mammals is one of the most acute threats at their island breeding stations. Island restoration projects increasingly involve the eradication of invasive non-native mammals, with benefits for seabirds and other island fauna. To date, demonstrated benefits of invasive mammal eradication include increased seabird nesting success and enhanced adult survival. However, the recovery dynamics of seabird populations have not been documented. Drawing on data from across the world, we assemble population growth rates (λ) of 181 seabird populations of 69 species following successful eradication projects. After successful eradication, the median growth rate was 1.119 and populations with positive growth (λ > 1; n = 151) greatly outnumbered those in decline (λ

More than US$21 billion is spent annually on biodiversity conservation. Despite their importance for preventing or slowing extinctions and preserving biodiversity, conservation interventions are rarely assessed systematically for their global impact. Islands house a disproportionately higher amount of biodiversity compared with mainlands, much of which is highly threatened with extinction. Indeed, island species make up nearly two-thirds of recent extinctions. Islands therefore are critical targets of conservation. We used an extensive literature and database review paired with expert interviews to estimate the global benefits of an increasingly used conservation action to stem biodiversity loss: eradication of invasive mammals on islands. We found 236 native terrestrial insular faunal species (596 populations) that benefitted through positive demographic and/or distributional responses from 251 eradications of invasive mammals on 181 islands. Seven native species (eight populations) were negatively impacted by invasive mammal eradication. Four threatened species had their International Union for the Conservation of Nature (IUCN) Red List extinction-risk categories reduced as a direct result of invasive mammal eradication, and no species moved to a higher extinction-risk category. We predict that 107 highly threatened birds, mammals, and reptiles on the IUCN Red List-6% of all these highly threatened species-likely have benefitted from invasive mammal eradications on islands. Because monitoring of eradication outcomes is sporadic and limited, the impacts of global eradications are likely greater than we report here. Our results highlight the importance of invasive mammal eradication on islands for protecting the world's most imperiled fauna.

We used a mitochondrial and nuclear DNA phylogeny to evaluate the relationships among all noddies (Anous and Procelsterna, Laridae) and to clarify their classification. The Lesser Noddy Anous tenuirostris and Black Noddy Anous minutus form a pair of closely related sister-species, as do the Blue Noddy Procelsterna albivitta and Grey Noddy Procelsterna cerulea. Blue and Grey Noddies are embedded within the dark noddies and are the sister-clade to the Lesser and Black Noddies, indicating that the genus Anous in its current definition is not monophyletic. Thus, we propose to merge all noddies into the genus Anous Stephens 1826, and to consider Procelsterna Lafresnaye 1842 as a junior synonym.

International audience; Invasive alien species are a major threat to native insular species. Eradicating invasive mammals from islands is a feasible and proven approach to prevent biodiversity loss. We developed a conceptual framework to identify globally important islands for invasive mammal eradications to prevent imminent extinctions of highly threatened species using biogeographic and technical factors, plus a novel approach to consider socio-political feasibility. We applied this framework using a comprehensive dataset describing the distribution of 1,184 highly threatened native vertebrate species (i.e. those listed as Critically Endangered or Endangered on the IUCN Red List) and 184 non-native mammals on 1,279 islands worldwide. Based on extinction risk, irreplaceability, severity of impact from invasive species, and technical feasibility of eradication, we identified and ranked 292 of the most important islands where eradicating invasive mammals would benefit highly threatened vertebrates. When socio-political feasibility was considered, we identified 169 of these islands where eradication planning or operation could be initiated by 2020 or 2030 and would improve the survival prospects of 9.4% of the Earth’s most highly threatened terrestrial insular vertebrates (111 of 1,184 species). Of these, 107 islands were in 34 countries and territories and could have eradication projects initiated by 2020. Concentrating efforts to eradicate invasive mammals on these 107 islands would benefit 151 populations of 80 highly threatened vertebrates and make a major contribution towards achieving global conservation targets adopted by the world’s nations.

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.

International audience; The geographic origin and migration of the brown rat (Rattus norvegicus) remain subjects of considerable debate. In this study, we sequenced whole genomes of 110 wild brown rats with a diverse world-wide representation. We reveal that brown rats migrated out of southern East Asia, rather than northern Asia as formerly suggested, into the Middle East and then to Europe and Africa, thousands of years ago. Comparison of genomes from different geographical populations reveals that many genes involved in the immune system experienced positive selection in the wild brown rat.

Background Leptospirosis is a bacterial zoonosis caused by pathogenic Leptospira for which rats are considered as the main reservoir. Disease incidence is higher in tropical countries, especially in insular ecosystems. Our objectives were to determine the current burden of leptospirosis in Seychelles, a country ranking first worldwide according to historical data, to establish epidemiological links between animal reservoirs and human disease, and to identify drivers of transmission. Methods A total of 223 patients with acute febrile symptoms of unknown origin were enrolled in a 12-months prospective study and tested for leptospirosis through real-time PCR, IgM ELISA and MAT. In addition, 739 rats trapped throughout the main island were investigated for Leptospira renal carriage. All molecularly confirmed positive samples were further genotyped. Results A total of 51 patients fulfilled the biological criteria of acute leptospirosis, corresponding to an annual incidence of 54.6 (95% CI 40.7–71.8) per 100,000 inhabitants. Leptospira carriage in Rattus spp. was overall low (7.7%) but dramatically higher in Rattus norvegicus (52.9%) than in Rattus rattus (4.4%). Leptospira interrogans was the only detected species in both humans and rats, and was represented by three distinct Sequence Types (STs). Two were novel STs identified in two thirds of acute human cases while noteworthily absent from rats. Conclusions This study shows that human leptospirosis still represents a heavy disease burden in Seychelles. Genotype data suggests that rats are actually not the main reservoir for human disease. We highlight a rather limited efficacy of preventive measures so far implemented in Seychelles. This could result from ineffective control measures of excreting animal populations, possibly due to a misidentification of the main contaminating reservoir(s). Altogether, presented data stimulate the exploration of alternative reservoir animal hosts., Author summary Leptospirosis is an emerging environmental infectious disease caused by corkscrew shaped bacteria called Leptospira. Humans usually get infected during recreational or work-related outdoor activities through contact with urine excreted by animal reservoirs. As a zoonotic disease, leptospirosis is a good example of the One Health concept for it links humans, animals and ecosystems in a web of pathogen maintenance and transmission. This zoonosis is highly prevalent in the tropics and especially in tropical islands. Seychelles archipelago has been reported as the country with highest human incidence worldwide, although figures are based on dated studies and/or poorly specific tests. The presented investigation aimed at providing an updated information on human leptospirosis burden in Seychelles and exploring the transmission chains in their environmental aspects. Presented data confirms that the disease still heavily impacts the country. Genotyping of pathogenic Leptospira in human acute cases reveals that three distinct Sequence Types (STs) are involved in the disease. However, rats typically considered as the main reservoir in Seychelles, harbor only one of these STs, found only in a minority of human cases. Hence, it appears that rats are likely not the main reservoir of leptospirosis in Seychelles, which has important consequences in terms of preventive measures to be implemented for a better control of human leptospirosis.

The brown rat (Rattus norvegicus) is found wherever humans live and transmits many diseases, and its breeding produced the laboratory rat used widely in medical research. Here, we sequenced whole genomes from 118 rats to explore the origin and dispersal routes of the brown rat and the domestication of the laboratory rat. We showed that brown rats migrated about 3600 years ago from southern East Asia, rather than Northern Asia as formerly suggested, to the Middle East and then to Europe and Africa. Many genes involved in the immune system experienced positive selection in the wild brown rat, while genes involved in the nervous system and energy metabolism showed evidence of artificial selection during the domestication of laboratory strains. Our findings demystify the puzzling origin and migration of brown rats and reveal the impact of evolution and domestication on this animal.

The giant tortoises (Aldabrachelys or Dipsochelys) of the Indian Ocean Islands have been in decline since the first human settlement of the islands. They retain only a single natural population on Aldabra Atoll (and possibly Ile aux Cerfs, where tortoises are descendants of a mixture of indigenous and imported animals). Several additional wild populations are known, resulting from reintroductions to the historic range and introductions outside of that range. The historical distribution of tortoises in Seychelles is summarized, with reliable tortoise records from only 4 coralline islands and 23 granitic islands and the status of all the wild populations reviewed. This includes the first census of the Fregate Island population. In the granitic islands, only 9 islands support tortoises today and the wild population of these islands is estimated at 500–550 adults. In the coralline islands, tortoises are now present on 11 islands, with a total population of over 100,000 (almost all on Aldabra). Climat...

Post-release monitoring is an important aspect of species transfers, providing a basis for conservation and management actions to achieve long-term survival of the species. Between 2001 and 2003, the Seychelles White-eye Zosterops modestus became established on Frégate Island following the transfer of 37 adult colour-ringed birds from Conception Island. Capture and colour ringing of birds was undertaken at regular intervals to keep the majority of the population banded. As the population grew, sampling methodologies became necessary to estimate its size accurately. Here, we compare the results obtained between November 2005 and January 2006 using three different methods: (1) capture–mark–relocate (NOREMARK); (2) point-transect with ‘distance sampling’, and (3) direct systematic surveys. Fifty point counts of 10 min each were conducted and replicated three times. The estimate by capture–mark–relocate was 77 individuals (72–83; P < 0.05) with better precision over distance sampling: 78 individuals (44–136; P < 0.05). The result from direct systematic surveys (81) indicated that estimates obtained with the two indirect methods were reliable. Based on present and previous method comparisons, we recommend using the capture–mark–relocate method for its higher precision and the NOREMARK program to determine sizes of island populations with a significant proportion of marked individuals.OSTRICH 2011, 82(2): 87–94

Two terrapin subspecies are currently considered Seychelles endemisms and Critically Endangered according to IUCN criteria, with several conservation measures having been proposed and actively initiated in the recent years. We use molecular data to examine their population diversity and structure across the archipelago and find a complete lack of variation at the mtDNA level. This can be explained by the strong founder effect associated with island colonisation, allied to the low evolution rate described for turtle mtDNA. However, a very recent arrival of Seychellois terrapins to the archipelago by human action cannot be discarded. The use of highly variable markers such as microsatellites and the clarification of their (native or not) status is therefore essential and should be implemented as an urgent priority in species management plans. Some differentiation between the Seychellois and Malagasy P. castanoides is observed but should be taken carefully until geographically broad level sampling across Madagascar is available.