Conservation du gecko vert de Manapany (Phelsuma inexpectata) et du puffin du Pacifique (Ardenna pacifica). Approche multispécifique pour la conservation des falaises littorales du sud de l’île de La Réunion.

The southern coastal cliffs of Reunion Island (tropical island in the Western Indian Ocean) host a unique flora and fauna: the last populations of Manapany day gecko (Phelsuma inexpectata, an endemic reptile in critically endangered), relics of indigenous vegetation including endemic and/or threatened species (e.g.: Euphorbia viridula, Psiadia retusa, Latania lontaroides) and breeding colonies of three native seabirds (white-tailed tropicbirds, Phaethon lepturus ; brown noddies, Anous stolidus and wedge-tailed shearwaters, Ardenna pacifica). This biodiversity is threatened by habitat transformations due to invasive plants, human activities (urbanization and culture) and invasive mammals (especially cats, felis catus, and rodents). Moreover, little is known about biology and ecology of the native species, which does not allow the implementation of effective conservation strategy. Based on hand-in-hand collaboration between researchers (UMR ENTROPIE) and managers (CDL, NOI, AVE2M) working on different taxa, the aim of this thesis was to provide multispecies conservation prescriptions on cliffs study for the Manapany day gecko and the wedge-tailed shearwater. We undertook a progressive approach from describing of species conservation states through understanding threatening processes to the prescription and monitoring of management actions. Three research topics were targeted: (i) demography and reproductive biology, (ii) terrestrial habitat requirements, and (iii) impacts and management of invasive mammals (especially cats). Our results highlighted the critical conservation state of Manapany day geckos and wedge-tailed shearwaters populations. Invasive plants and mammals (especially cats) are threats to the conservation of native biodiversity. We provide several local and general conservation prescriptions, including management of invasive species, multispecies terrestrial habitat restoration and captive head-start program of Manapany day geckos. Several of these prescriptions were implemented during this thesis (invasive species management and captive breeding program) and monitored as part of active adaptive management approach. This multispecies study at the interface between research and management must be continued and supported by a strong federating regulatory tool as a National Nature Reserve (NNR).Le littoral sud de La Réunion (île tropicale de l’océan Indien) est composé de falaises spectaculaires abritant une faune et une flore remarquable. On y retrouve les dernières populations sauvages de geckos verts de Manapany (Phelsumainexpectata, un reptile endémique en danger critique d’extinction), des reliques de végétation indigènes littoralescomprenant certaines espèces menacées et/ou endémiques (ex. : Euphorbia viridula, Psiadia retusa, Latanialontaroides,…), ainsi que des sites de reproduction de trois espèces d’oiseaux marins indigènes (le paille-en-queue à brins blancs, Phaethon lepturus ; le puffin du Pacifique, Ardenna pacifica ; et le noddi brun, Anous stolidus). Cette biodiversité subit des menaces importantes, notamment la transformation des habitats par la végétation exotique envahissante, les activités humaines (ex. : urbanisation, culture) et les mammifères introduits (ex. : chats, Felis catus ; rongeurs). Par ailleurs,les connaissances sur cet écosystème littoral sont lacunaires, tant sur la biologie des espèces que sur leur écologie, ce qui ne permet pas de mettre en place des mesures de gestion adaptées. Fondée sur une collaboration entre chercheurs (UMRENTROPIE) et gestionnaires (CDL, NOI, AVE2M) travaillant sur des taxons différents (reptiles, oiseaux marins), cette thèse avait pour objectifs d’apporter des solutions de gestion multispécifique pour conserver deux espèces patrimoniales de ces falaises : le gecko vert de Manapany et le puffin du Pacifique. Nous avons entrepris une démarche progressive de la description de l’état de conservation des espèces, en passant par la compréhension des menaces, jusqu’au suivi des actions de conservation prescrites. Trois axes de recherche ont été ciblés : (i) la démographique et la biologie de la reproduction,(ii) les besoins écologiques concernant des habitats terrestres, et (iii) les impacts et la gestion des mammifères exotiques(notamment les chats). Nos résultats montrent que les populations de geckos verts de Manapany et de puffins du Pacifique sont dans des états critiques de conservation. Les pestes végétales et les mammifères exotiques (tout particulièrement les chats) sont des menaces pour la préservation des deux espèces. Nous apportons plusieurs prescriptions de gestion locales et applicables à d’autres écosystèmes insulaires, notamment concernant la gestion des mammifères exotiques, la restauration multispécifique de l’habitat terrestre, et la mise en place d’un élevage de geckos ex-situ. Plusieurs de ces recommandation sont pu être mises en place durant cette thèse (contrôle des prédateurs, élevage transitoire de geckos) et certaines suivies dans le cadre d’une démarche adaptative active. Ces travaux de conservation multispécifiques, à l’interface entre recherche et gestion, devraient continuer et être soutenus par des outils règlementaires fédérateurs de grande ampleur, comme par exemple la mise en place d’une Réserve Naturelle Nationale (RNN)

Conservation du gecko vert de Manapany (Phelsuma inexpectata) et du puffin du Pacifique (Ardenna pacifica). Approche multispécifique pour la conservation des falaises littorales du sud de l’île de La Réunion.

The southern coastal cliffs of Reunion Island (tropical island in the Western Indian Ocean) host a unique flora and fauna: the last populations of Manapany day gecko (Phelsuma inexpectata, an endemic reptile in critically endangered), relics of indigenous vegetation including endemic and/or threatened species (e.g.: Euphorbia viridula, Psiadia retusa, Latania lontaroides) and breeding colonies of three native seabirds (white-tailed tropicbirds, Phaethon lepturus ; brown noddies, Anous stolidus and wedge-tailed shearwaters, Ardenna pacifica). This biodiversity is threatened by habitat transformations due to invasive plants, human activities (urbanization and culture) and invasive mammals (especially cats, felis catus, and rodents). Moreover, little is known about biology and ecology of the native species, which does not allow the implementation of effective conservation strategy. Based on hand-in-hand collaboration between researchers (UMR ENTROPIE) and managers (CDL, NOI, AVE2M) working on different taxa, the aim of this thesis was to provide multispecies conservation prescriptions on cliffs study for the Manapany day gecko and the wedge-tailed shearwater. We undertook a progressive approach from describing of species conservation states through understanding threatening processes to the prescription and monitoring of management actions. Three research topics were targeted: (i) demography and reproductive biology, (ii) terrestrial habitat requirements, and (iii) impacts and management of invasive mammals (especially cats). Our results highlighted the critical conservation state of Manapany day geckos and wedge-tailed shearwaters populations. Invasive plants and mammals (especially cats) are threats to the conservation of native biodiversity. We provide several local and general conservation prescriptions, including management of invasive species, multispecies terrestrial habitat restoration and captive head-start program of Manapany day geckos. Several of these prescriptions were implemented during this thesis (invasive species management and captive breeding program) and monitored as part of active adaptive management approach. This multispecies study at the interface between research and management must be continued and supported by a strong federating regulatory tool as a National Nature Reserve (NNR).Le littoral sud de La Réunion (île tropicale de l’océan Indien) est composé de falaises spectaculaires abritant une faune et une flore remarquable. On y retrouve les dernières populations sauvages de geckos verts de Manapany (Phelsumainexpectata, un reptile endémique en danger critique d’extinction), des reliques de végétation indigènes littoralescomprenant certaines espèces menacées et/ou endémiques (ex. : Euphorbia viridula, Psiadia retusa, Latanialontaroides,…), ainsi que des sites de reproduction de trois espèces d’oiseaux marins indigènes (le paille-en-queue à brins blancs, Phaethon lepturus ; le puffin du Pacifique, Ardenna pacifica ; et le noddi brun, Anous stolidus). Cette biodiversité subit des menaces importantes, notamment la transformation des habitats par la végétation exotique envahissante, les activités humaines (ex. : urbanisation, culture) et les mammifères introduits (ex. : chats, Felis catus ; rongeurs). Par ailleurs,les connaissances sur cet écosystème littoral sont lacunaires, tant sur la biologie des espèces que sur leur écologie, ce qui ne permet pas de mettre en place des mesures de gestion adaptées. Fondée sur une collaboration entre chercheurs (UMRENTROPIE) et gestionnaires (CDL, NOI, AVE2M) travaillant sur des taxons différents (reptiles, oiseaux marins), cette thèse avait pour objectifs d’apporter des solutions de gestion multispécifique pour conserver deux espèces patrimoniales de ces falaises : le gecko vert de Manapany et le puffin du Pacifique. Nous avons entrepris une démarche progressive de la description de l’état de conservation des espèces, en passant par la compréhension des menaces, jusqu’au suivi des actions de conservation prescrites. Trois axes de recherche ont été ciblés : (i) la démographique et la biologie de la reproduction,(ii) les besoins écologiques concernant des habitats terrestres, et (iii) les impacts et la gestion des mammifères exotiques(notamment les chats). Nos résultats montrent que les populations de geckos verts de Manapany et de puffins du Pacifique sont dans des états critiques de conservation. Les pestes végétales et les mammifères exotiques (tout particulièrement les chats) sont des menaces pour la préservation des deux espèces. Nous apportons plusieurs prescriptions de gestion locales et applicables à d’autres écosystèmes insulaires, notamment concernant la gestion des mammifères exotiques, la restauration multispécifique de l’habitat terrestre, et la mise en place d’un élevage de geckos ex-situ. Plusieurs de ces recommandation sont pu être mises en place durant cette thèse (contrôle des prédateurs, élevage transitoire de geckos) et certaines suivies dans le cadre d’une démarche adaptative active. Ces travaux de conservation multispécifiques, à l’interface entre recherche et gestion, devraient continuer et être soutenus par des outils règlementaires fédérateurs de grande ampleur, comme par exemple la mise en place d’une Réserve Naturelle Nationale (RNN)

Conservation of the Manapany day gecko (Phelsuma inexpectata) and the wedge-tailed shearwater (Ardenna pacifica). Multispecies approach for the conservation of the southern coastal cliffs of Reunion Island.

Le littoral sud de La Réunion (île tropicale de l’océan Indien) est composé de falaises spectaculaires abritant une faune et une flore remarquable. On y retrouve les dernières populations sauvages de geckos verts de Manapany (Phelsumainexpectata, un reptile endémique en danger critique d’extinction), des reliques de végétation indigènes littoralescomprenant certaines espèces menacées et/ou endémiques (ex. : Euphorbia viridula, Psiadia retusa, Latanialontaroides,…), ainsi que des sites de reproduction de trois espèces d’oiseaux marins indigènes (le paille-en-queue à brins blancs, Phaethon lepturus ; le puffin du Pacifique, Ardenna pacifica ; et le noddi brun, Anous stolidus). Cette biodiversité subit des menaces importantes, notamment la transformation des habitats par la végétation exotique envahissante, les activités humaines (ex. : urbanisation, culture) et les mammifères introduits (ex. : chats, Felis catus ; rongeurs). Par ailleurs,les connaissances sur cet écosystème littoral sont lacunaires, tant sur la biologie des espèces que sur leur écologie, ce qui ne permet pas de mettre en place des mesures de gestion adaptées. Fondée sur une collaboration entre chercheurs (UMRENTROPIE) et gestionnaires (CDL, NOI, AVE2M) travaillant sur des taxons différents (reptiles, oiseaux marins), cette thèse avait pour objectifs d’apporter des solutions de gestion multispécifique pour conserver deux espèces patrimoniales de ces falaises : le gecko vert de Manapany et le puffin du Pacifique. Nous avons entrepris une démarche progressive de la description de l’état de conservation des espèces, en passant par la compréhension des menaces, jusqu’au suivi des actions de conservation prescrites. Trois axes de recherche ont été ciblés : (i) la démographique et la biologie de la reproduction,(ii) les besoins écologiques concernant des habitats terrestres, et (iii) les impacts et la gestion des mammifères exotiques(notamment les chats). Nos résultats montrent que les populations de geckos verts de Manapany et de puffins du Pacifique sont dans des états critiques de conservation. Les pestes végétales et les mammifères exotiques (tout particulièrement les chats) sont des menaces pour la préservation des deux espèces. Nous apportons plusieurs prescriptions de gestion locales et applicables à d’autres écosystèmes insulaires, notamment concernant la gestion des mammifères exotiques, la restauration multispécifique de l’habitat terrestre, et la mise en place d’un élevage de geckos ex-situ. Plusieurs de ces recommandation sont pu être mises en place durant cette thèse (contrôle des prédateurs, élevage transitoire de geckos) et certaines suivies dans le cadre d’une démarche adaptative active. Ces travaux de conservation multispécifiques, à l’interface entre recherche et gestion, devraient continuer et être soutenus par des outils règlementaires fédérateurs de grande ampleur, comme par exemple la mise en place d’une Réserve Naturelle Nationale (RNN).The southern coastal cliffs of Reunion Island (tropical island in the Western Indian Ocean) host a unique flora and fauna: the last populations of Manapany day gecko (Phelsuma inexpectata, an endemic reptile in critically endangered), relics of indigenous vegetation including endemic and/or threatened species (e.g.: Euphorbia viridula, Psiadia retusa, Latania lontaroides) and breeding colonies of three native seabirds (white-tailed tropicbirds, Phaethon lepturus ; brown noddies, Anous stolidus and wedge-tailed shearwaters, Ardenna pacifica). This biodiversity is threatened by habitat transformations due to invasive plants, human activities (urbanization and culture) and invasive mammals (especially cats, felis catus, and rodents). Moreover, little is known about biology and ecology of the native species, which does not allow the implementation of effective conservation strategy. Based on hand-in-hand collaboration between researchers (UMR ENTROPIE) and managers (CDL, NOI, AVE2M) working on different taxa, the aim of this thesis was to provide multispecies conservation prescriptions on cliffs study for the Manapany day gecko and the wedge-tailed shearwater. We undertook a progressive approach from describing of species conservation states through understanding threatening processes to the prescription and monitoring of management actions. Three research topics were targeted: (i) demography and reproductive biology, (ii) terrestrial habitat requirements, and (iii) impacts and management of invasive mammals (especially cats). Our results highlighted the critical conservation state of Manapany day geckos and wedge-tailed shearwaters populations. Invasive plants and mammals (especially cats) are threats to the conservation of native biodiversity. We provide several local and general conservation prescriptions, including management of invasive species, multispecies terrestrial habitat restoration and captive head-start program of Manapany day geckos. Several of these prescriptions were implemented during this thesis (invasive species management and captive breeding program) and monitored as part of active adaptive management approach. This multispecies study at the interface between research and management must be continued and supported by a strong federating regulatory tool as a National Nature Reserve (NNR)

Evidence of seasonal reproduction, laying site fidelity, and oviposition synchronicity in the critically endangered endemic Manapany Day Gecko (Phelsuma inexpectata) from Reunion Island (western Indian Ocean)

The reproductive phenology of tropical geckos varies considerably between species. We investigated the reproductive timing of Phelsuma inexpectata, a critically endangered tropical squamate endemic to Reunion Island (western Indian Ocean). From February 2018 to August 2020 (30 months), we carried out monthly monitoring of laying sites. Phelsuma inexpectata exhibited a seasonal reproductive pattern, with breeding activity from the end of the austral winter to the end of the austral summer. We observed intra- and interannual synchronicity of oviposition in September. The seasonal  reproductive pattern appears to be synchronized with optimal environmental conditions (temperatures, food resources) for the survival of eggs and hatchlings. Females deposited their eggs in communal laying sites (up to 9 eggs) and exhibited interannual laying site fidelity (50% of the laying sites were reused in the second breeding season). Minimum and maximum incubation periods (± SD) were 69 ± 24 days and 115 ± 25 days, respectively. Our study provides the first description of the Manapany Day Gecko reproduction in the wild and highlights for the first time the very high synchronicity of oviposition in the genus Phelsuma. These results will be very useful to improve the conservation of this species, in particular with regard to the timing of predator control, designing monitoring protocols for breeding and survival parameters, and implementing a captive rearing program for hatchlings

Evidence of seasonal reproduction, laying site fidelity, and oviposition synchronicity in the critically endangered endemic Manapany Day Gecko (Phelsuma inexpectata) from Reunion Island (western Indian Ocean)

International audienceThe reproductive phenology of tropical geckos varies considerably between species. We investigated the reproductive timing of Phelsuma inexpectata, a critically endangered tropical squamate endemic to Reunion Island (western Indian Ocean). From February 2018 to August 2020 (30 months), we carried out monthly monitoring of laying sites. Phelsuma inexpectata exhibited a seasonal reproductive pattern, with breeding activity from the end of the austral winter to the end of the austral summer. We observed intra-and interannual synchronicity of oviposition in September. The seasonal reproductive pattern appears to be synchronized with optimal environmental conditions (temperatures, food resources) for the survival of eggs and hatchlings. Females deposited their eggs in communal laying sites (up to 9 eggs) and exhibited interannual laying site fidelity (50% of the laying sites were reused in the second breeding season). Minimum and maximum incubation periods (± SD) were 69 ± 24 days and 115 ± 25 days, respectively. Our study provides the first description of the Manapany Day Gecko reproduction in the wild and highlights for the first time the very high synchronicity of oviposition in the genus Phelsuma. These results will be very useful to improve the conservation of this species, in particular with regard to the timing of predator control, designing monitoring protocols for breeding and survival parameters, and implementing a captive rearing program for hatchlings

Cantate de noël - symphonie pour cordes / HONEGGER

Titre uniforme : [Symphonies. No 2. H 153]BnF-Partenariats, Collection sonore - BelieveContient une table des matière

Isolation and characterization of 50 microsatellite loci for two shearwater species, Ardenna pacifica and Puffinus bailloni

Background: Shearwaters (order Procellariiformes) are an excellent study system to investigate the genetic consequences of the co-called “seabird paradox”, as they are able to disperse long distances but many species exhibit natal and breeding philopatry. However, few microsatellite markers are currently available for these taxa, hampering genetic inferences. Methods and results: In this study, 25 novel microsatellite loci were isolated and characterized for each of two distantly related shearwater species: the wedge-tailed shearwater (Ardenna pacifica) and the tropical shearwater (Puffinus bailloni). Polymorphism tests were performed for a total of 91 A. pacifica individuals sampled at Reunion and Round Island, and 48 P. bailloni individuals from Reunion and Europa Island, in the western Indian Ocean. The analyses revealed 23 polymorphic loci for A. pacifica, with the number of alleles per locus (Na) ranging from 2 to 8 (mean = 3.957 ± 0.364). Nineteen polymorphic loci were found for P. bailloni, with Na varying from two to five (mean = 3.053 ± 0.247). The observed heterozygosity (Ho) was relatively low for the two species, with Ho ranging from 0.022 to 0.725 (mean = 0.326 ± 0.044) for A. pacifica and from 0.021 to 0.688 (mean = 0.271 ± 0.051) for P. bailloni, but comparable to the estimates available for other Puffinus species. Conclusions: The new microsatellite loci provide a valuable tool for further population genetic studies, and will allow for design of effective conservation and management plans for A. pacifica, P. bailloni and other closely-related species

Choice of climate data influences predictions for current and future global invasion risks for two Phelsuma geckos

International audienceAbstract Invasion risks may be influenced either negatively or positively by climate change, depending on the species. These can be predicted with species distribution models, but projections can be strongly affected by the source of the environmental data (climate data source, Global Circulation Models GCM and Shared Socio-economic Pathways SSP). We modelled the distribution of Phelsuma grandis and P. laticauda , two Malagasy reptiles that are spreading globally. We accounted for drivers of spread and establishment using socio-economic factors (e.g., distance from ports) and two climate data sources, i.e., Climatologies at High Resolution for the Earth’s and Land Surface Areas (CHELSA) and Worldclim. We further quantified the degree of agreement in invasion risk models that utilised CHELSA and Worldclim data for current and future conditions. Most areas identified as highly exposed to invasion risks were consistently identified (e.g. in Caribbean and Pacific Islands). However, projected risks differed locally. We also found notable differences in quantitative invasion risk (3% difference in suitability scores for P. laticauda and up to 14% for P. grandis ) under current conditions. Despite both species native distributions overlapping substantially, climate change will drive opposite responses on invasion risks by 2070 (decrease for P. grandis, increase for P. laticauda ). Overall, projections of future invasion risks were the most affected by climate data source, followed by SSP. Our results highlight that assessments of current and future invasion risks are sensitive to the climate data source, especially in islands. We stress the need to account for multiple climatologies when assessing invasion risks

Application of genetic and Spatially Explicit Capture-Recapture analyses to design adaptive feral cat control in a large inhabited island

Faunas of oceanic islands have a high proportion of endemic species which contribute to the uniqueness of island communities. Island species are particularly naïve and vulnerable to alien predators, such as cats (Felis catus). On large, inhabited islands, where the complete eradication of feral cat populations is not considered feasible, control represents the best management option to lower their detrimental effects on native fauna. The first objective of our study was to investigate population genetics of feral cats of Réunion Island. The second objective was to understand the space use of feral cats established near the breeding colonies of the two endemic and endangered seabirds of Réunion Island, the Barau’s Petrel (Pterodroma baraui) and the Mascarene Petrel (Pseudobulweria aterrima). We evaluated genetic diversity, population structure and gene flow amongst six groups of feral cats located at a maximum of 10 km from known petrel colonies. We also analysed the behaviour and space use of one of these feral cat groups using camera-trap data and Spatially Explicit Capture-Recapture (SECR) models. Genetic analyses revealed that feral cats were structured in three genetic clusters explained mostly by the island topography. Two clusters were observed at five sampled sites, suggesting high connectivity amongst these sites. The last cluster was found in only one site, suggesting high isolation. This site was a remote mountain area located in the vicinity of one of the main Barau’s Petrel colonies. The behavioural study was conducted on this isolated feral cat population. Mark recapture analysis suggested that feral cats were present at low density and had large home ranges, which is probably explained by reduced food availability. Finally, we make several recommendations for refining feral cat management programmes on inhabited islands

Application of genetic and Spatially Explicit Capture-Recapture analyses to design adaptive feral cat control in a large inhabited island

International audienceFaunas of oceanic islands have a high proportion of endemic species which contribute to the uniqueness of island communities. Island species are particularly naïve and vulnerable to alien predators, such as cats (Felis catus). On large, inhabited islands, where the complete eradication of feral cat populations is not considered feasible, control represents the best management option to lower their detrimental effects on native fauna. The first objective of our study was to investigate population genetics of feral cats of Réunion Island. The second objective was to understand the space use of feral cats established near the breeding colonies of the two endemic and endangered seabirds of Réunion Island, the Barau’s Petrel (Pterodroma baraui) and the Mascarene Petrel (Pseudobulweria aterrima). We evaluated genetic diversity, population structure and gene flow amongst six groups of feral cats located at a maximum of 10 km from known petrel colonies. We also analysed the behaviour and space use of one of these feral cat groups using camera-trap data and Spatially Explicit Capture-Recapture (SECR) models. Genetic analyses revealed that feral cats were structured in three genetic clusters explained mostly by the island topography. Two clusters were observed at five sampled sites, suggesting high connectivity amongst these sites. The last cluster was found in only one site, suggesting high isolation. This site was a remote mountain area located in the vicinity of one of the main Barau’s Petrel colonies. The behavioural study was conducted on this isolated feral cat population. Mark recapture analysis suggested that feral cats were present at low density and had large home ranges, which is probably explained by reduced food availability. Finally, we make several recommendations for refining feral cat management programmes on inhabited islands