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Leptospirosis is a bacterial zoonosis that occurs in tropical and subtropical regions worldwide. Chiroptera are known to be a formidable reservoir of zoonotic pathogens, including leptospires. The epidemiology of leptospirosis in bats in the Pacific Islands is poorly known, both in terms of prevalence and in terms of the bacterial strains involved. A strong host specificity between leptospiral strains and their mammalian reservoir is recognized. This phenomenon has notably been studied recently in bat communities, providing strong evidence of co-evolution. In New Caledonia, a biodiversity hotspot where leptospirosis is endemic and enzootic, Chiroptera are the only indigenous terrestrial mammals. In this study, we aimed to investigate leptospires associated with three flying fox species in New Caledonia. Kidneys and urine samples of Pteropus spp. from captures and seizures were analysed. Among 254 flying foxes analysed, 24 harboured pathogenic leptospires corresponding to an observed prevalence of 9.45% with 15.8% on the Main Island and 4.3% on Loyalty Islands. The analysis of the rrs gene, lfb1, and MLST sequences evidenced four distinct clusters of undescribed strains, likely corresponding to undescribed species. All four strains belong to the Group I of pathogenic Leptospira spp., which includes Leptospira interrogans, Leptospira noguchii, and Leptospira kirschneri. We detected pathogenic leptospires in all three Pteropus spp. studied (including two endemic species) with no evidence of host specificity in two co-roosting species. For a better understanding of Leptospira-host co-evolution, notably to genetically characterize and evaluate the virulence of these original bat-associated leptospires, it is essential to improve isolation techniques. Flying foxes are traditionally hunted and eaten in New Caledonia, a massive cause of bat-human interactions. Our results should encourage vigilance during these contacts to limit the spillover risk of these pathogens to humans.

International audience; Cats Felis catus, in all their forms (domestic, free-roaming/stray and feral), have been identified as a major global threat to biodiversity, especially birds and small mammals. However, there has been little previous consideration of the extent and impact of predation of bats by cats, or of whether specific characteristics make certain species of bats particularly vulnerable to predation by cats. We reviewed the impact of cats on bats, based on a collation of scientific literature and the International Union for Conservation of Nature (IUCN) Red List database. Our aim was to produce a synthesis of the extent to which cats prey upon and threaten bats. We also collated available data on cat diet, which provide information on predation rates of bats by cats. Few studies (n = 44) have identified bat species preyed upon or threatened by cats, with a disproportionate number of studies from islands. In these studies, 86 bat species (about 7% of the global extant tally) are reported as preyed upon or threatened by cats, and about one quarter of these species are listed as Near Threatened or threatened (IUCN categories Critically Endangered, Endangered, or Vulnerable). In IUCN Red List assessments, cats are more frequently mentioned as a threat to threatened or Near Threatened bat species than to non-threatened species (IUCN category Least Concern). In studies reporting on the incidence of bats in cat dietary samples (scats, stomachs and guts), the frequency of occurrence of bats in samples averaged 0.7 ± 2.1% (mean ± standard deviation; n = 102). Many studies had sample sizes that were too small to be likely to detect bats. All forms of cat are reported to kill bats, and such predation has been reported in all major terrestrial habitats. We conclude that predation by cats is an under-appreciated threat to the world’s bat species.

Size and shape variations of shells can be used to identify natural phenotypic clusters and thus delimit snail species. Here, we apply both supervised and unsupervised machine learning algorithms to a geometric morphometric dataset to investigate size and shape variations of the shells of the endemic land snail Placostylus from New Caledonia. We sampled eight populations of Placostylus from the Isle of Pines, where two species of this genus reportedly coexist. We used neural network analysis as a supervised learning algorithm and Gaussian mixture models as an unsupervised learning algorithm. Using a training dataset of individuals assigned to species using nuclear markers, we found that supervised learning algorithms could not unambiguously classify all individuals of our expanded dataset using shell size and shape. Unsupervised learning showed that the optimal division of our data consisted of three phenotypic clusters. Two of these clusters correspond to the established species Placostylus fibratus and P. porphyrostomus, while the third cluster was intermediate in both shape and size. Most of the individuals that were not clearly classified using supervised learning were classified to this intermediate phenotype by unsupervised learning, and most of these individuals came from previously unsampled populations. These results may indicate the presence of persistent putative-hybrid populations of Placostylus in the Isle of Pines.

Hunting is a major threat to many species of wildlife. However, managing hunting systems to ensure their sustainability requires a thorough demographic knowledge about the impact of hunting. Here we develop a framework integrating ecological, modelling and sociological data to achieve a sustainability assessment of flying-fox hunting in New Caledonia and assess the relative merits of alternative management policies. Using age-specific stochastic population models, we found that the current annual hunting rate [5.5−8.5%] is likely to lead to a severe decline (− 79%) of Pteropus populations over the next 30 years. However, a majority of hunters surveyed (60%) were willing to soften their practices, offering an opportunity for adaptive management. Recurrent temporary hunting ban (at least 1 year out of 2) in combination with protected areas (≥ 25%) appears as the most effective and most accepted management option. Our integrative approach appears to be a promising method for ensuring that traditional hunting systems can remain sustainable in a rapidly changing world. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13280-021-01630-x.

Background Hemotropic mycoplasmas, previously classified in the genus Eperythrozoon, have been reported as causing human infections in Brazil, China, Japan, and Spain. Methods In 2017, we detected DNA from Candidatus Mycoplasma haemohominis in the blood of a Melanesian patient from New Caledonia presenting with febrile splenomegaly, weight loss, life-threatening autoimmune hemolytic anemia, and hemophagocytosis. The full genome of the bacterium was sequenced from a blood isolate. Subsequently, we retrospectively (2011–2017) and prospectively (2018–2019) tested patients who had been hospitalized with a similar clinico-biological picture. In addition, as these patients had been in contact with frugivorous bats (authorized under conditions for hunting and eating in New Caledonia), we investigated the role of these animals and their biting flies by testing them for hemotropic mycoplasmas. Results There were 15 patients found to be infected by this hemotropic mycoplasma. Among them, 4 (27%) died following splenectomy performed either for spontaneous spleen rupture or to cure refractory autoimmune hemolytic anemia. The bacterium was cultivated from the patient’s blood. The full genome of the Neocaledonian Candidatus M. haemohominis strain differed from that of a recently identified Japanese strain. Of 40 tested Pteropus bats, 40% were positive; 100% of collected bat flies Cyclopodia horsfieldi (Nycteribiidae, Diptera) were positive. Human, bat, and dipteran strains were highly similar. Conclusions The bacterium being widely distributed in bats, Candidatus M. haemohominis, should be regarded as a potential cause of severe infections in humans.

International audience; Previous studies have mainly focused on bat mortality through collision by wind turbines, and very few studies have assessed the indirect impacts on bat activity and on foraging habitat availability. Also, there is a global lack of knowledge on the vulnerability of tropical bat fauna due to wind energy production, even though it is well known that windpower can affect bat communities and biodiversity hotspots are widespread in the tropics. We present one of the first studies to quantify the indirect impact of wind farms on insectivorous bats in tropical hotspots of biodiversity. Bat activity was compared between wind farm sites and control sites, via ultrasound recordings at stationary points. The activity of bent winged bats (Miniopterus sp) and wattled bats (Chalinolobus sp) were both significantly lower at wind turbine sites. The result of the study demonstrates a large effect on bat habitat use at wind turbines sites compared to control sites. Bat activity was 20 times higher at control sites compared to wind turbine sites, which suggests that habitat loss is an important impact to consider in wind farm planning We strongly recommend that the loss of the foraging habitat loss is considered in mitigation hierarchy (avoiding, reducing, offsetting) when compensating or negative impacts of wind farms.

Invasive alien species are a major cause of biodiversity loss globally, but especially on islands where high species richness and levels of endemism accentuate their impacts. The Red vented bulbul (Pycnonotus cafer), a tropical passerine bird that has been introduced widely across locations of high conservation value, is considered an extreme pest. It is currently expanding its range in New Caledonia, one of the world's biodiversity hotspots. Decisive recommendations on management strategies are required urgently to inform local managers and policy makers, but they should be based on quantitative local evidence, not just on expert opinion. The Red-vented bulbul is widely blamed for its impacts on biodiversity, especially through competition. We used data from 2,472 point counts to explore the abundance relationships between the Red-vented bulbul and 14 other species of bird. Our results revealed a negative relationship between the occurrence of the bulbul and the mean abundance of nine species, all native (or endemic, n = 3) to the New Caledonia archipelago. In contrast, the abundance of other introduced species such as Acridotheres tristis (Common myna), Passer domesticus (House sparrow) and Spilopelia chinensis (Spotted dove) were not affected by the Red-vented bulbul. Moreover, temporal trends in the abundance of impacted species suggest that the Red-vented bulbul may cause niche contractions rather than mortality for native species in man-modified habitats. Monitoring and control of the Red-vented bulbul is recommended to prevent on-going impacts on native bird communities throughout New Caledonia, and its impact on native bird communities elsewhere should be quantified.

International audience; The biodiversity hotspot of New Caledonia hosts high levels of endemism (74% of flora) that is threatened increasingly by climate change, habitat reduction, and inva-sive species. The fruit-eating red-vented bulbul (Pycnonotus cafer) is currently invading the main island of the archipelago, and its recent dispersal out of urbanized habitats raises questions about its potential to disperse noxious plant seeds along urban corridors and beyond. Indeed, the red-vented bulbul is considered a vector of several introduced plant species in its alien range including Miconia calvescens, Lantana camara, and Schinus terebinthifolius. We conducted a quantitative assessment of the bulbul's fruits consumption by analyzing the gut contents of shot birds. We estimated gut passage times for four species of fruit found in gut contents (S. terebin-thifolius, Myrtastrum rufopunctatum, Passiflora suberosa, and Ficus prolixa) and tested the effects of bird digestion on seed germination rates for two species. Finally, we monitored the movements of individual VHF radio-tagged red-vented bulbuls. All of the consumed fruit species we identified here have red fleshy diaspore, including fruit of the shrub M. rufopunctatum that occurred frequently (9.6%) in bulbul gut samples. Median gut passage times were short (15-41 min), corresponding to short-distance seed transportation (77-92 m). The effect of gut passage was positive for the germination of the invasive S. terebinthifolius and negative for the endemic M. ru-fopunctatum, suggesting a potential bias in the contribution to the dispersal toward alien species. This study provides the first integrated assessment of mechanisms involved in the seed dispersal effectiveness of this high-concern invasive bird species that is expected to face similar plant communities in most of its alien range in tropical islands. More generally, our results enhance knowledge of synergies between non-native frugivores and plant species dispersal.

International audience; Recently, debate has flourished about inadequacies in the simplistic ''worst invasive spe-cies'' approach and its global scale. Here we investigate the status of the red-vented bulbul (Pycnonotus cafer), an Asian passerine bird. This species has been introduced widely across Pacific islands and is commonly blamed for its impacts on agriculture and biodiversity via dispersal of invasive plant seeds and competition with native fauna. This case study evaluates all available data on the impacts and management of this invasive species and identifies priorities for future research. We reviewed the scientific literature and information from three databases (ABBA, GAVIA, eBird) and highlight that the attention paid to this species by scientists and managers varied considerably between islands and contexts and was globally lower than the attention paid to other species on the IUCN-ISSG list. The red-vented bulbul has now established on 37 islands and in seven continental locations outside its native range. We show that three categories of effects are associated with this species: plant damage, seed dispersal and disturbance of fauna. We compiled lists of 110 plant species consumed, 33 plant species dispersed, and 15 species of bird that this bulbul interacts with. However, these lists were mainly made of opportunistic observations rather than specific assessments. Research outputs that focus on better ways to prevent or quantify the impacts of the red-vented bulbul remain scarce. We found very few references exploring potential positive impacts of this species, and only two examples of management actions undertaken against it. The latter are required to inform management actions, especially on sensitive tropical islands where invasions and dispersal of the red-vented bulbul are ongoing. Our analysis of the literature found no clear support for considering this species to be one of the ''world's worst'' invasive alien species.

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.

L'intérêt est grandissant pour le potentiel présenté par les acccumulations cavernicoles de guano de chauves-souris et d'oiseaux en tant qu'enregistrements stratigraphiques continentaux, complémentaires voire alternatifs aux archives étudiées généralement (sédiments lacustres, palustres, tourbeux, etc.). Ces dépôts permettent des reconstructions de la variabilité climatique à haute résolution pour des échelles de temps récentes à plus anciennes, grâce à la calibration de nouveaux proxies susceptibles d'enregistrer ces variations. Ainsi la comparaison du contenu pollinique et des traceurs isotopiques delta 13C et delta D des n-alcanes du guano de différents animaux insectivores, les salanganes diurnes (Collocalia spodiopygia) et les chiroptères nocturnes (Micropterus robustior) cohabitant dans de nombreuses grottes de Nouvelle-Calédonie, met en évidence une grande variabilité. Celle-ci est à l'image des cibles de nourrissage des proies appétées et de leur interaction avec les composantes de l'écosystème, en particulier les plantes. La grande richesse du contenu pollinique observée dans les deux types de guano, bien que présentant 50 % de taxons communs, souligne des aires de nourrissage préférentielles. Elle montre aussi des fluctuations interannuelles, marqueurs probables de changements environnementaux, sinon climatiques. Cet article présente des premiers résultats obtenus sur le sondage HAK1 prélévé dans un amas de guano de salanganes de la grotte Hama sur l'île de Lifou, l'une des îles Loyautés. La comparaison entre les données de géochimie isotopique moléculaire (isotopes du carbone delta 13C et de l'hydrogène delta D du n-alcane C29) et les données pluviométriques met en évidence une bonne covariation interprétée comme marqueur du signal climatique ENSO contemporain des dépôts de guano analysés. Ce travail préliminaire confirme le fort potentiel des amas de guano cavernicoles pour étudier à haute résolution les changements paléo-environnementaux.

International audience; Squamata are one of the most threatened groups among island vertebrates, facing high pressure from exotic species. However, the contribution of small terrestrial reptiles in invasive rodents' diet remains poorly investigated, partly because of the lack of tools for accurately identifying chewed prey fragments in gut contents. The New Caledonia archipelago (South Pacific) hosts an exceptional terrestrial squamata fauna (105 species, 91.6% endemic) that are faced with many invasive species (rodents, feral cats, feral pigs, ants) and strong human pressures. Our study aimed to evaluate the frequency of occurrence of endemic skink remains by gut content analysis of two species of invasive rodents. Four rodent trapping sessions were implemented at two ultramafic sites and for two distinct habitats (closed canopy forest and open shrubland habitat). A total of 284 rats were trapped from two species (the ship rat Rattus rattus and the Pacific rat R. exulans) over 1200 trap nights. Combined analysis of stomach and caecum contents provided far more information than traditional stomach analysis alone. Analyses showed that 15.9% of rat samples included remains of at least 12 different skink species out of the 23 present. Six species are classified as threatened by the IUCN, the most endangered being Marmorosphax taom (CR) and Kanakysaurus viviparus (EN). This study provides new prospects for the assessment of invasive rodent impacts and new insights into the respective impacts of two sympatric invasive rodent species on native skinks.

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 edible Placostylus snails of New Caledonia occur across a wide range of environmental conditions, from the dry southwest to the wetter central and northeastern regions. In large, slow-moving animals such as Placostylus, speciation could be assumed to be largely driven by allopatry and genetic drift as opposed to natural selection. We examined variation in shell morphology using geometric morphometrics and genetic structure within two species of Placostylus (P. fibratus, P. porphyrostomus), to determine the drivers of diversity in this group. Despite the current patchy distribution of snails on New Caledonia, both mtDNA and nuclear SNP data sets (>3000 loci) showed weak admixing between populations and species. Shell morphology was concordant with the genetic clusters we identified and had a strong relationship with local environment. The genetic data, in contrast to the morphological data, did not show concordance with climatic conditions, suggesting the snails are not limited in their ability to adapt to different environments. In sympatry, P. fibratus and P. porphyrostomus maintained genetic and morphological differences, suggesting a genetic basis of phenotypic variation. Convergence of shell shape was observed in two adjacent populations that are genetically isolated but experience similar habitat and climatic conditions. Conversely, some populations in contrasting environments were morphologically distinct although genetically indistinguishable. We infer that morphological divergence in the Placostylus snails of New Caledonia is mediated by adaptation to the local environment.

Background Widespread but particularly incident in the tropics, leptospirosis is transmitted to humans directly or indirectly by virtually any Mammal species. However, rodents are recognized as the most important reservoir. In endemic regions, seasonal outbreaks are observed during hot rainy periods. In such regions, hot spots can be evidenced, where leptospirosis is “hyper-endemic”, its incidence reaching 500 annual cases per 100,000. A better knowledge of how rodent populations and their Leptospira prevalence respond to seasonal and meteorological fluctuations might help implement relevant control measures. Methodology/Principal Findings In two tribes in New Caledonia with hyper-endemic leptospirosis, rodent abundance and Leptospira prevalence was studied twice a year, in hot and cool seasons for two consecutive years. Highly contrasted meteorological situations, particularly rainfall intensities, were noted between the two hot seasons studied. Our results show that during a hot and rainy period, both the rodent populations and their Leptospira carriage were higher. This pattern was more salient in commensal rodents than in the sylvatic rats. Conclusions/Significance The dynamics of rodents and their Leptospira carriage changed during the survey, probably under the influence of meteorology. Rodents were both more numerous and more frequently carrying (therefore disseminating) leptospires during a hot rainy period, also corresponding to a flooding period with higher risks of human exposure to waters and watered soils. The outbreaks of leptospirosis in hyper-endemic areas could arise from meteorological conditions leading to both an increased risk of exposure of humans and an increased volume of the rodent reservoir. Rodent control measures would therefore be most effective during cool and dry seasons, when rodent populations and leptospirosis incidence are low., Author Summary In this study, we surveyed rodents and their Leptospira carriage in an area where human leptospirosis is hyper-endemic. We evidenced the well-known associations between specific rodent species and particular leptospires in both mice and rats. Overall, the observed Leptospira prevalence was in the range 18–47% depending on species, similar to other descriptions. However, significant variations were observed both in the abundance of rodents and their Leptospira carriage, one hot period with heavy rain being associated with both a highest abundance and an increased prevalence. Similar meteorological conditions could lead to increased leptospires dispersal by the rodent reservoir and increased exposure of humans to risk situations (e.g. flood, mud). Because rodent control measures were demonstrated elsewhere to be cost-effective if correctly planned and implemented, this contribution to a better knowledge of rodent and leptospires dynamics provides useful information and may in turn allow to develop relevant rodent control actions aimed at reducing the burden of human leptospirosis.

Sous reserve d'accepter les definitions d'invasion biologique et d'espece envahissante enoncees en introduction, les donnees disponibles, souvent incompletes, permettent de conclure qu'entre 2000 ans avant J.-C. et aujourd'hui, et pour l'ensemble des iles de la Nouvelle-Caledonie, 279 especes de vertebres terrestres ou d'eau douce et saumâtre y ont constitue ou constituent actuellement des populations reproductrices et perennes. Parmi ces especes, dix-huit ont disparu du territoire au cours des quatre derniers millenaires et seize d'entre elles, endemiques de Nouvelle-Caledonie, sont actuellement eteintes. Quatorze de ces disparitions sont intervenues pendant la periode melanesienne, ce qui represente un taux de 0,4 disparition par siecle, et quatre pendant la periode historique, soit 1,6 disparition par siecle. Pendant ce meme laps de temps, quarante-deux especes de vertebres ont envahi la Nouvelle-Caledonie: quatre d'entre elles spontanement et trente-huit qui ont ete introduites, deliberement ou non, par l'homme. Une seule a ete introduite de facon certaine pendant l'epoque melanesienne, soit 0,03 introduction par siecle, et trente-sept pendant l'epoque historique, soit 14,8 introductions par siecle. Ces deux resultats soulignent le role majeur joue par l'homme dans l'evolution recente de la composition de la faune de vertebres du territoire. Au nombre des trente-huit especes introduites par l'homme figurent 12 especes de la liste IUCN des 100 especes qui, introduites, engendrent les dysfonctionnements les plus importants aux ecosystemes d'accueil. Par ailleurs, l'impact de la quasi-totalite des especes allochtones sur leurs ecosystemes d'accueil neo-caledoniens est non documente. Enfin, aucune de ces especes ne fait actuellement l'objet de mesure de gestion globale a but affiche environnemental. La Grande Terre qui heberge la totalite des especes allochtones presentes sur le territoire, constitue une importante source d'especes allochtones pour l'ensemble des autres iles de la Nouvelle-Caledonie. Ce risque est d'autant plus important que les especes en question ont fait la preuve de leur capacite a parvenir en Nouvelle-Caledonie et a coloniser plusieurs de ses ecosystemes. Ce risque est egalement important en raison de la proximite geographique et des relations privilegiees qu'entretient la Grande Terre avec ces iles en terme de volume de trafic de marchandises et de passagers. Ce risque est enfin important parce que les motivations a l'origine de certaines introductions sur la Grande Terre (cynegetique, peche, colombophilie, aquariophilie, nouvelles especes d'animaux de compagnie, etc.) sont tout a fait susceptibles de voir le jour sur les iles habitees ou non qui sont actuellement depourvues de ces especes allochtones. Par ailleurs, deux especes endemiques de la Grande Terre ont ete introduites sur les iles Loyaute. De telles introductions peuvent apparaitre legitimes, voire salvatrices dans certains cas. C'est oublier que toute introduction a des consequences et que de telles introductions sont a proscrire en l'absence de solides travaux d'ecologie permettant d'en apprecier de facon fondee les risques au regard des avantages. En consequence, les mesures qui doivent etre prises pour limiter les introductions d'especes allochtones depuis l'exterieur du territoire doivent egalement etre mises en application au sein du territoire. Notons que la promulgation de ces mesures et leur application ne releveraient que des autorites territoriales et ne se heurteraient pas aux difficultes que peuvent soulever des regles conduisant a limiter les echanges commerciaux internationaux. (Resume d'auteur)

New Caledonia is recognized as one of the main hotspots on the world. Unfortunately, its exceptional biodiversity is threatened by the rapid development of human activities. Hence, impacted natural environments must be restored to maintain the ecosystem services they provide. The main objective of this study was to propose the establishment of active restoration by ecological continuities which take into account mode of dispersion, germination of plant species as well as the distances from plantations to natural vegetation. For answer to this objective, the implementation of a database containing the characteristics of dispersal, dormancy and desiccation tolerance of seeds of 407 taxa found in maquis or both maquis and forest was carried out. Then, an evaluation of the recovery progress of revegetated areas by plantation was carried out. Finally, floristic inventories in the natural vegetations of the area study have enable to characterize their structure, their composition and to determine 37 vegetal species called "candidate" to be prioritized in the future restoration projects, by their high phenotypic plasticity allowing thern to develop both in open and closed environments. Twelve of thern have been the subject of a phonological (flower and fruit) and germination study., La Nouvelle-Calédonie est reconnue comme l'un des principaux "hotspots" de la planète. Malheureusement, sa biodiversité exceptionnelle est menacée par le développement rapide des activités humaines. De ce fait, les milieux naturels impactés se doivent d'être restaurés pour maintenir les services écosystémiques qu'ils rendent.L'objectif principal de ce travail de recherche a été de proposer la mise en place de la restauration active par des connectivités écologiques qui prennent en compte les modes de dispersion, la germination d'espèces végétales ainsi que les distances des plantations aux végétations existantes. Pour répondre à cet objectif, l'implémentation d'une base de données comprenant les caractéristiques de dispersion, de dormance et de la tolérance à la dessiccation des graines de 407 taxons retrouvés en maquis ou à la fois en maquis et en forêt a été réalisée dans un premier temps. Puis, dans un second temps, une évaluation du progrès de rétablissement de zones anciennement revégétalisées par plantation a été réalisée. Enfin, dans un troisième temps, des inventaires floristiques dans les végétations des milieux naturels de la zone ont permis de caractériser leur structure, leur composition et de déterminer 37 espèces végétales dites « candidates » à prioriser dans les futurs projets de restauration, de par leur forte plasticité phénotypique leur permettant de se développer à la fois en milieux ouverts et fermés. Douze d'entre-elles ont fait l'objet d'un suivi phénologique et d'une étude germinative.

La Nouvelle-Calédonie est reconnue comme l'un des principaux "hotspots" de la planète. Malheureusement, sa biodiversité exceptionnelle est menacée par le développement rapide des activités humaines. De ce fait, les milieux naturels impactés se doivent d'être restaurés pour maintenir les services écosystémiques qu'ils rendent.L'objectif principal de ce travail de recherche a été de proposer la mise en place de la restauration active par des connectivités écologiques qui prennent en compte les modes de dispersion, la germination d'espèces végétales ainsi que les distances des plantations aux végétations existantes. Pour répondre à cet objectif, l'implémentation d'une base de données comprenant les caractéristiques de dispersion, de dormance et de la tolérance à la dessiccation des graines de 407 taxons retrouvés en maquis ou à la fois en maquis et en forêt a été réalisée dans un premier temps. Puis, dans un second temps, une évaluation du progrès de rétablissement de zones anciennement revégétalisées par plantation a été réalisée. Enfin, dans un troisième temps, des inventaires floristiques dans les végétations des milieux naturels de la zone ont permis de caractériser leur structure, leur composition et de déterminer 37 espèces végétales dites « candidates » à prioriser dans les futurs projets de restauration, de par leur forte plasticité phénotypique leur permettant de se développer à la fois en milieux ouverts et fermés. Douze d'entre-elles ont fait l'objet d'un suivi phénologique et d'une étude germinative., New Caledonia is recognized as one of the main hotspots on the world. Unfortunately, its exceptional biodiversity is threatened by the rapid development of human activities. Hence, impacted natural environments must be restored to maintain the ecosystem services they provide. The main objective of this study was to propose the establishment of active restoration by ecological continuities which take into account mode of dispersion, germination of plant species as well as the distances from plantations to natural vegetation. For answer to this objective, the implementation of a database containing the characteristics of dispersal, dormancy and desiccation tolerance of seeds of 407 taxa found in maquis or both maquis and forest was carried out. Then, an evaluation of the recovery progress of revegetated areas by plantation was carried out. Finally, floristic inventories in the natural vegetations of the area study have enable to characterize their structure, their composition and to determine 37 vegetal species called "candidate" to be prioritized in the future restoration projects, by their high phenotypic plasticity allowing thern to develop both in open and closed environments. Twelve of thern have been the subject of a phonological (flower and fruit) and germination study.

Invasive exotic species degrade ecosystems and are a threat to biodiversity (case of the invasive birds in this report) (Soubeyran, 2008). As part of a control plan of the red-vented bulbul (Pycnonotus cafer L.) in New-Caledonia, studies have been done on trapping methods and on foraging behaviors of the bulbul. The different procedures of trapping involved 2 types of cages, 5 types of fruit-baits (real fruit and fake fruit) and the presence or absence of a live bird as a decoy in the traps. In total, 59 bulbuls were captured in the traps and 118 bulbuls were observed in the wild. Differences between trapping methods were significant. The most effective methods were the banana fruit-baits (46% of the catches) and papaya (35% of the catches), the presence of a decoy in the traps (76% of the catches) and the cage-trap called "camembert" (68% of the catches). In the study of the foraging behavior of the red-vented bulbul, it has been observed feeding on 16 different plant species of which 7 are invasive species. Berries and fruits were their preferred form of sustenance (80% of the observations) and their preferred height was at more than 3 meters (> 75% of the observations). The behaviours most observed were "scanning" (> 50%) and "singing" (20%). The results obtained during these studies have allowed for a certain number of recommendations to be put forwards as to the development of the trapping method and the pursuit of scientific endeavors with the aim of sustainable control of the red-vented bulbul population in New-Caledonia.; Les Espèces Exotiques Envahissantes (EEE) altèrent les écosystèmes et menacent la biodiversité (cas des oiseaux envahissants ici) (Soubeyran, 2008). Dans le cadre d'un plan de régulation du bulbul à ventre rouge (Pycnonotus cafer L.) en gestation en Nouvelle-Calédonie, des études sur les modalités de piégeage et le comportement de cet oiseau invasif ont été réalisées. Les modalités de piégeage testées comprenaient deux types de cage, 5 appâts (fruits et fruits artificiels) et la présence ou l'absence d'un appelant dans les pièges. Au total, 59 bulbuls ont été capturés dans les pièges et 118 bulbuls ont été observés en milieu naturel. Des différences significatives de captures ont été observées en fonction des modalités de piégeages, les plus efficaces étant les appâts banane (46% des captures) et papaye (35% des captures), la présence d'un appelant dans les pièges (76% des captures) et la cage "camembert" (68% des captures). Lors de l'étude du comportement, le bulbul a été observé se nourrissant sur 16 espèces végétales, dont 7 espèces envahissantes. Les baies et fruits ont été principalement consommés (>80%). La position préférée de l'oiseau était perché sur des végétaux (80% des observations) à plus de 3 m de haut (>75%). Les comportements les plus observés ont été "scruter" (>50%) et "chanter" (20%). Les résultats obtenus lors de ces études ont permis d'émettre un certain nombre de recommandations pour l'adaptation de la technique de piégeage et la poursuite des travaux scientifiques dans un but d'une régulation durable des populations de bulbuls en Nouvelle-Calédonie.