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Narrow-ranging species are usually omitted from Species distribution models (SDMs) due to statistical constraints, while they are predicted to be particularly vulnerable to climate change. The recently available high-resolution environmental predictors, along with recently developed methods enable to increase the eligibility of narrow-ranging species for SDMs, provided their distribution is well known. We fill a gap of knowledge on the effect of predicted climate change on narrow-ranging species. We modelled the distribution of the golden mantella frog Mantella aurantiaca and the Manapany day gecko Phelsuma inexpectata, for which the distribution of their occurrence records is well documented. Our modelling scheme included a range of processes susceptible to address statistical issues related to narrow-ranging species. We predict an alarming decline in climate suitability in the whole current distribution area of both species by 2070, potentially leading to a complete extinction in most scenarios. We identified the areas with the best climate suitability in the future, but these remain largely suboptimal regarding species climatic niche. The high level of habitat fragmentation suggests that both species likely need to be at least partly translocated. Climate change may not only drive range contractions or distribution shifts in narrow-ranging species, but may lead to the complete extirpation of suitable environments across their entire region. This study suggests that the level of threats of narrow-ranging species already identified as threatened may be underestimated, especially in heterogeneous tropical areas. We stress the need to develop sampling campaigns and implement proactive actions for narrow-ranging species in the tropics.

Narrow-ranging species are usually omitted from Species distribution models (SDMs) due to statistical constraints, while they are predicted to be particularly vulnerable to climate change. The recently available high-resolution environmental predictors, along with recently developed methods enable to increase the eligibility of narrow-ranging species for SDMs, provided their distribution is well known. We fill a gap of knowledge on the effect of predicted climate change on narrow-ranging species. We modelled the distribution of the golden mantella frog Mantella aurantiaca and the Manapany day gecko Phelsuma inexpectata, for which the distribution of their occurrence records is well documented. Our modelling scheme included a range of processes susceptible to address statistical issues related to narrow-ranging species. We predict an alarming decline in climate suitability in the whole current distribution area of both species by 2070, potentially leading to a complete extinction in most scenarios. We identified the areas with the best climate suitability in the future, but these remain largely suboptimal regarding species climatic niche. The high level of habitat fragmentation suggests that both species likely need to be at least partly translocated. Climate change may not only drive range contractions or distribution shifts in narrow-ranging species, but may lead to the complete extirpation of suitable environments across their entire region. This study suggests that the level of threats of narrow-ranging species already identified as threatened may be underestimated, especially in heterogeneous tropical areas. We stress the need to develop sampling campaigns and implement proactive actions for narrow-ranging species in the tropics.

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).

Commonly seen as either dangerous or unsocial, reptiles represent a kind of alterity that is often deemed categorically different from warm-blooded mammals. In the village of Manapany-les-Bains, however, on the island of La Reunion in the Western Indian Ocean, care for the endangered gecko species Phelsuma inexpectata has taken an unexpected turn: initiated by a local NGO, village residents have declared their private gardens a gecko-friendly zone. Engaging concepts of multispecies care and alterity, this article explores what caring for a reptile means. Based on ethnographic field research in Manapany-les-Bains, I will discuss how the gecko’s otherness remains an ambivalent trope, being both reduced and capitalized on, and that new alliances are exclusionary and fragmented.

Mitochondrial (12SrRNA and cyt b, 1086 bp) and nuclear (c-mos, 374 bp) DNA sequences were used to investigate relationships and biogeography of 24 living and extinct taxa of Phelsuma geckos. Monophyly of Phelsuma and sister relationship to the SW African Rhoptropella is corroborated. Phelsuma originated on Madagascar and made multiple long-distance invasions of oceanic islands including the Mascarenes, Aldabra, Comores, Seychelles, Andamans, and perhaps Pemba. The Mascarenes were probably colonised once, about 4.2-5.1Ma, and here Phelsuma rosagularis and Phelsuma inexpectata are newly recognised as species, as are three lineages of Phelsuma cepediana. Mascarene relationships are: Phelsuma edwardnewtoni, Phelsuma gigas (Phelsuma guentheri ((((P. cepediana A (P. cepediana B, C)) P. rosagularis) Phelsuma borbonica) ((Phelsuma ornata, P. inexpectata) Phelsuma guimbeaui))). The two recently extinct species, P. edwardnewtoni and the giant secondarily nocturnal Phelsuma gigas, differentiated on Rodrigues while on Mauritius the large nocturnal P. guentheri separated from a small diurnal form that radiated into six species, a likely result of volcanic activity. Two small-bodied lineages from Mauritius invaded the more recent island of Réunion producing two more species. Outside the Mascarenes, two mainly Madagascan assemblages are substantiated: Phelsuma serraticauda (Phelsuma lineata, Phelsuma laticauda, Phelsuma quadriocellata); (Phelsuma m. kochi (Phelsuma m. grandis, Phelsuma abboti)) (Phelsuma astriata, Phelsuma sundbergi). Their relationships to the Mascarene clade, and to Phelsuma mutabilis, Phelsuma standingi and Phelsuma andamanensis are unresolved.

Interspecific kleptoparasitism (the stealing of already-procured items from other species) has received little attention in tropical reptiles. We report here the second case of kleptoparasitism in tropical lizards, and the first known case of pollen theft by a vertebrate species. Phelsuma inexpectata, a gekkonid lizard endemic to Réunion, was observed robbing pollen pellets from honeybees (Apis mellifera) foraging on Latania lontaroides flowers. Video-records were used to obtain reliable information on gecko-honeybee interactions occurring on L. lontaroides inflorescences. During the 19 observation periods (total duration 140 min) a total of 78 attempts were recorded, at least 40% were successful. Both males and females displayed kleptoparasitic behaviour. A high level of gecko kleptoparasitism occurred, with an average one-robbery attempt every 2 min. Behaviour of both the kleptoparasitic P. inexpectata and its host A. mellifera are described.