The Experts below are selected from a list of 366 Experts worldwide ranked by ideXlab platform
Sanchez Mickaël - One of the best experts on this subject based on the ideXlab platform.
-
Consommation de Geckos verts de Bourbon, Phelsuma borbonica Mertens, 1966, par le Busard de Maillard, Circus maillardi J. Verreaux, 1862, sur l’île de La Réunion (Squamata : Gekkonidae ; Accipitriformes : Accipitridae)
Association Réunionnaise d'Ecologie, 2021Co-Authors: Ferret Pierrick, Sanchez MickaëlAbstract:Le Busard de Maillard Circus maillardi est le dernier rapace nicheur endémique de La Réunion. A l'heure d'aujourd'hui, son régime alimentaire semble principalement composé d'espèces exotiques introduites par l'homme (mammifères, reptiles, oiseaux). Néanmoins, la consommation de Gecko vert de Bourbon Phelsuma borbonica, espèce également endémique de La Réunion, illustre en partie ce que devait-être le régime alimentaire du rapace avant la colonisation de l'île
-
New record of day geckos feeding on orchid nectar in Reunion Island: can lizards pollinate orchid species?
Societas Europaea Herpetologica, 2014Co-Authors: Bègue Jean-françois, Sanchez Mickaël, Micheneau Claire, Fournel JacquesAbstract:[Extract] Lizard pollination is common among insular floras, often being viewed as an island phenomenon (e.g. Withaker, 1987; Olesen and Valido, 2003; Godinez-Alvarez, 2004). Especially, the genus Phelsuma represents a key taxon in the reproduction of many native plant species (Nyhagen et al., 2001; Hansen, Beer and Muller, 2006; Hansen and Muller 2009; Le Péchon et al., 2013). Day geckos are mainly distributed in the southwestern region of the Indian Ocean (e.g. Austin, Arnold and Jones, 2004). These arboreal lizards are known to include a major component of nectar and pollen in their diet (e.g. Nyhagen et al., 2001; Olesen, Eskildsen and Venkatasamy, 2002; Kaiser 2006; Desoet al., 2008; Olesen et al., 2012; Clémencet et al., 2013; Minaar et al., 2013), and recent studies, conducted on Mauritius' and Reunion's floras (Mascarene Archipelago), have shown that lizard pollination involves a wide range of plant families, including Rousseaceae (Hansen and Müller 2009), Malvaceae (Hansen, Beer and Muller, 2006; Hansen et al., 2007; Le Péchon et al., 2013) and Araliaceae (Nyhagen et al., 2001). In some cases, pollination by Phelsuma species is vital to ensure sexual reproduction of native endangered plants species (Nyhagen et al., 2001; Hansen, Beer and Muller, 2006; Hansen and Müller 2009). To date, only one observation of a Phelsuma visiting orchid flowers has been reported (Micheneau et al., 2010), and beside this "single day gecko visit" in Reunion Island, only one case of lizard feeding on orchid nectar has been reported in Caymans Island (Burton, 2008), but on extra-floral nectaries only without visiting the flowers of Myrmecophila thomsoniana (Rchb. f.) Rolfe. Here we described and discussed the first case of Phelsuma interactions with flowers from the orchid family in Reunion Island, involving the endemic day gecko Phelsuma borbonica Mertens, 1966 visiting flowers of Angraecum cadetii Bosser (endemic to Reunion and Mauritius) and Angraecum bracteosum Balf. & S. Moore (endemic to Reunion)
-
Régime alimentaire du grand gecko vert de Madagascar, Phelsuma grandis Gray, 1870 sur l'île de La Réunion (Squamata : Gekkonidae)
Association Réunionnaise d'Ecologie, 2013Co-Authors: Dervin Sébastien, Baret Samuel, Sanchez MickaëlAbstract:RÉSUMÉ : Phelsuma grandis Gray, 1870 est un gecko introduit sur l’île de La Réunion. Le régime alimentaire de ce reptile, considéré comme invasif, a été étudié afin d’évaluer la menace qu'il pourrait représenter pour la faune indigène. Le contenu stomacal de 171 individus a été analysé. À La Réunion, P. grandis se nourrit principalement d’Arthropodes. Les ressources végétales occupent également une part non négligeable de son alimentation et il consomme régulièrement d’autres espèces de geckos. P. grandis manifeste un comportement alimentaire de type opportuniste, à large spectre de proies. Ces résultats indiquent que P. grandis pourrait avoir des incidences négatives importantes sur la faune locale, notamment sur l’entomofaune et l’herpétofaune par prédation ou par compétition.ABSTRACT:Phelsuma grandis Gray, 1870 is an introduced invasive gecko at Reunion Island. The aim of the present study was to assess its diet in order to evaluate the threat it could represent for native fauna. Stomach contents of 171 individuals were analyzed. At Reunion Island, P. grandis feeds mostly on arthropods and, to a lesser extent, plant materials. P. grandis feeds also, and regularly, onother gecko species. P. grandis shows an opportunistic feeding behavior with a broad spectrum of prey. These outcomes indicate that P. grandis may have significant negative impacts on the local wildlife, including entomofauna and herpetofauna, through predation or competition.MOTS CLÉS : Phelsuma grandis, espèce invasive, prédation, écosystèmes insulaires.KEYWORDS : Phelsuma grandis, invasive species, predation, island ecosystems
-
Record d'altitude pour la couleuvre loup, Lycodon aulicus (L., 1758) sur l'île de La Réunion (Squamata : Colubridae)
Association Réunionnaise d'Ecologie, 2013Co-Authors: Hollinger Clémence, Piscione Eric, Payet Janik, Sanchez MickaëlAbstract:Le 22 mai 2013, lors d’une sortie de terrain conduite par les agents du Parc national de La Réunion visant à suivre une population de gecko vert de Bourbon (Phelsuma borbonica Mertens, 1966), une couleuvre loup a été découverte au niveau du site du Maïdo (commune de Saint-Paul), à 2215 mètres d’altitude
-
Kleptoparasitism in the endemic gecko Phelsuma inexpectata: pollen theft from foraging honeybees on Réunion
'Cambridge University Press (CUP)', 2013Co-Authors: Clémencet Johanna, Aubert Cyril, Blottière Doriane, Sanchez MickaëlAbstract:International audienceInterspecific 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
Vences Miguel - One of the best experts on this subject based on the ideXlab platform.
-
The Andaman day gecko paradox: an ancient endemic without pronounced phylogeographic structure
'Springer Science and Business Media LLC', 2020Co-Authors: Moha Ashwini, Orozco-terwengel Pablo, Shanke Kartik, Vences MiguelAbstract:The Andaman day gecko (Phelsuma andamanensis) is endemic to the Andaman Archipelago, located ~ 6000 km away from Madagascar where the genus Phelsuma likely evolved. We complemented existing phylogenetic data with additional markers to show that this species consistently branches off early in the evolution of the genus Phelsuma, and this early origin led us to hypothesize that island populations within the Andaman Archipelago could have further diversified. We sampled the Andaman day gecko from all major islands in the Andamans, developed new microsatellite markers and amplified mitochondrial markers to study population diversification. We detected high allelic diversity in microsatellites, but surprisingly poor geographical structuring. This study demonstrates that the Andaman day gecko has a panmictic population (K = 1), but with weak signals for two clusters that we name ‘North’ (North Andaman, Middle Andaman, Interview, Baratang, Neil, and Long Islands) and ‘South’ (Havelock, South Andaman, Little Andaman Islands). The mitochondrial COI gene uncovered wide haplotype sharing across islands with the presence of several private haplotypes (except for the Little Andaman Island, which only had an exclusive private haplotype) signalling ongoing admixture. This species differs from two other Andaman endemic geckos for which we provide comparative mitochondrial data, where haplotypes show a distinct phylogeographic structure. Testing population history scenarios for the Andaman day gecko using Approximate Bayesian Computation (ABC) supports two possible scenarios but fails to tease apart whether admixture or divergence produced the two weak clusters. Both scenarios agree that admixture and/or divergence prior to the onset of the last glacial maximum shaped the genetic diversity and structure detected in this study. ABC supports population expansion, possibly explained by anthropogenic food subsidies via plantations of cash crops, potentially coupled with human mediated dispersal resulting in the observed panmictic population. The Andaman day gecko may thus be a rare example of an island endemic reptile benefiting from habitat modification and increased movement in its native range
-
FIGURE 5. A in Deciphering the cryptic species diversity of dull-coloured day geckos Phelsuma (Squamata: Gekkonidae) from Madagascar, with description of a new species
2011Co-Authors: Crottini Angelica, Glaw Frank, Gehring Philip-sebastian, Harris James, Lima Alexandra, Vences MiguelAbstract:FIGURE 5. A possible individual of Phelsuma gouldi from near Betroka in life, photo by Hans-Peter Berghof
-
FIGURE 4 in Deciphering the cryptic species diversity of dull-coloured day geckos Phelsuma (Squamata: Gekkonidae) from Madagascar, with description of a new species
2011Co-Authors: Crottini Angelica, Glaw Frank, Gehring Philip-sebastian, Harris James, Lima Alexandra, Vences MiguelAbstract:FIGURE 4. Bayesian inference tree based on 358 bp of the mitochondrial 16S rRNA gene. Phelsuma standingi was used as an outgroup. Values at nodes are bootstrap values in percent from MP analyses; values below 70% not shown. Asterisks denote Bayesian posterior probabilities values: (*), 90–94%; *, 95–98%; **, 99–100%. Numbers 1, 2 and 3 denote the three major clades identified within the analysed samples of P. mutabilis
-
FIGURE 6 in Phylogenetic systematics of day geckos, genus Phelsuma, based on molecular and morphological data (Squamata: Gekkonidae)
2010Co-Authors: Rocha Sara, Glaw Frank, Gehring Philip-sebastian, Harris James, Rösler Herbert, Posada David, Vences MiguelAbstract:FIGURE 6. BI tree of available sequences of a fragment of the 16S rRNA gene in specimens of the Phelsuma madagascariensis group. Branches in bold are supported by PP values of 100; other relevant PP values above 50 are given as numbers
-
FIGURE 3 in Phylogenetic systematics of day geckos, genus Phelsuma, based on molecular and morphological data (Squamata: Gekkonidae)
2010Co-Authors: Rocha Sara, Glaw Frank, Gehring Philip-sebastian, Harris James, Rösler Herbert, Posada David, Vences MiguelAbstract:FIGURE 3. Molecular phylogeny of the Phelsuma mutabilis group as calculated from the multi-gene dataset of Rocha et al. (2009). Shown are the respective clades from the Bayesian 50% majority-rule consensus trees based on (a) the combined dataset of mitochondrial and nuclear genes, (b) the mitochondrial genes only, and (c) the nuclear genes only. See caption to Fig. 2 for further explanations
Stephen Harris - One of the best experts on this subject based on the ideXlab platform.
-
Ecological Effects of the Invasive Giant Madagascar Day Gecko on Endemic Mauritian Geckos: Applications of Binomial-Mixture and Species Distribution Models
2020Co-Authors: Stephen Harris, Steeves Buckland, Laura E Gallagher, N C Cole, J Aguirre-gutiérrez, Besnard, A. .. S M HenshawAbstract:Buckland, S.; Cole, N.C.; Aguirre Gutierrez, J.; Gallagher, L.E.; Henshaw, S.M.; Besnard, A.; Tucker, R.M.; Bachraz, V.; Ruhomaun, K.; Harris, S. Published in: PLoS ONE DOI: 10.1371/journal.pone.0088798 Link to publication Citation for published version (APA): Buckland, S., Cole, N. C., Aguirre-Gutiérrez, J., Gallagher, L. E., Henshaw, S. M., Besnard, A., ... Harris, S. (2014) General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Abstract The invasion of the giant Madagascar day gecko Phelsuma grandis has increased the threats to the four endemic Mauritian day geckos (Phelsuma spp.) that have survived on mainland Mauritius. We had two main aims: (i) to predict the spatial distribution and overlap of P. grandis and the endemic geckos at a landscape level; and (ii) to investigate the effects of P. grandis on the abundance and risks of extinction of the endemic geckos at a local scale. An ensemble forecasting approach was used to predict the spatial distribution and overlap of P. grandis and the endemic geckos. We used hierarchical binomial mixture models and repeated visual estimate surveys to calculate the abundance of the endemic geckos in sites with and without P. grandis. The predicted range of each species varied from 85 km 2 to 376 km 2 . Sixty percent of the predicted range of P. grandis overlapped with the combined predicted ranges of the four endemic geckos; 15% of the combined predicted ranges of the four endemic geckos overlapped with P. grandis. Levin's niche breadth varied from 0.140 to 0.652 between P. grandis and the four endemic geckos. The abundance of endemic geckos was 89% lower in sites with P. grandis compared to sites without P. grandis, and the endemic geckos had been extirpated at four of ten sites we surveyed with P. grandis. Species Distribution Modelling, together with the breadth metrics, predicted that P. grandis can partly share the equivalent niche with endemic species and survive in a range of environmental conditions. We provide strong evidence that smaller endemic geckos are unlikely to survive in sympatry with P. grandis. This is a cause of concern in both Mauritius and other countries with endemic species of Phelsuma
-
High Risks of Losing Genetic Diversity in an Endemic Mauritian Gecko: Implications for Conservation
2016Co-Authors: Steeves Buckl, Laura E Gallagher, Nik C. Cole, Jim J. Groombridge, Terry Burke, Deborah A. Dawson, Stephen HarrisAbstract:Genetic structure can be a consequence of recent population fragmentation and isolation, or a remnant of historical localised adaptation. This poses a challenge for conservationists since misinterpreting patterns of genetic structure may lead to inappropriate management. Of 17 species of reptile originally found in Mauritius, only five survive on the main island. One of these, Phelsuma guimbeaui (lowland forest day gecko), is now restricted to 30 small isolated subpopulations following severe forest fragmentation and isolation due to human colonisation. We used 20 microsatellites in ten subpopulations and two mitochondrial DNA (mtDNA) markers in 13 subpopulations to: (i) assess genetic diversity, population structure and genetic differentiation of subpopulations; (ii) estimate effective population sizes and migration rates of subpopulations; and (iii) examine the phylogenetic relationships of haplotypes found in different subpopulations. Microsatellite data revealed significant population structure with high levels of genetic diversity and isolation by distance, substantial genetic differentiation and no migration between most subpopulations. MtDNA, however, showed no evidence of population structure, indicating that there was once a genetically panmictic population. Effective population sizes of ten subpopulations, based on microsatellite markers, were small, ranging from 44 to 167. Simulations suggested that the chance of survival and allelic diversity of some subpopulations will decrease dramatically over the next 50 years if no migration occurs. Our DNA-based evidence reveals an urgent need for a management plan for the conservation of P
-
Ecological Effects of the Invasive Giant Madagascar Day Gecko on Endemic Mauritian Geckos: Applications of Binomial-Mixture and Species Distribution Models
2015Co-Authors: Steeves Buckl, Laura E Gallagher, Sion M Henshaw, Rachel M Tucker, Vishnu Bachraz, Kevin Ruhomaun, Nik C. Cole, Stephen HarrisAbstract:The invasion of the giant Madagascar day gecko Phelsuma grandis has increased the threats to the four endemic Mauritian day geckos (Phelsuma spp.) that have survived on mainland Mauritius. We had two main aims: (i) to predict the spatial distribution and overlap of P. grandis and the endemic geckos at a landscape level; and (ii) to investigate the effects of P. grandis on the abundance and risks of extinction of the endemic geckos at a local scale. An ensemble forecasting approach was used to predict the spatial distribution and overlap of P. grandis and the endemic geckos. We used hierarchical binomial mixture models and repeated visual estimate surveys to calculate the abundance of the endemic geckos in sites with and without P. grandis. The predicted range of each species varied from 85 km2 to 376 km2. Sixty percent of the predicted range of P. grandis overlapped with the combined predicted ranges of the four endemic geckos; 15 % of the combined predicted ranges of the four endemic geckos overlapped with P. grandis. Levin’s niche breadth varied from 0.140 to 0.652 between P. grandis and the four endemic geckos. The abundance of endemic geckos was 89 % lower in sites with P. grandis compared to sites without P. grandis, and the endemic geckos had been extirpated at four of ten sites we surveyed with P. grandis. Species Distribution Modelling, together with the breadth metrics, predicted that P. grandis can partly share the equivalen
-
ecological effects of the invasive giant madagascar day gecko on endemic mauritian geckos applications of binomial mixture and species distribution models
PLOS ONE, 2014Co-Authors: Steeves Buckland, Nik Cole, Jesus Aguirregutierrez, Laura E Gallagher, Sion M Henshaw, Aurelien Besnard, Rachel M Tucker, Vishnu Bachraz, Kevin Ruhomaun, Stephen HarrisAbstract:The invasion of the giant Madagascar day gecko Phelsuma grandis has increased the threats to the four endemic Mauritian day geckos (Phelsuma spp.) that have survived on mainland Mauritius. We had two main aims: (i) to predict the spatial distribution and overlap of P. grandis and the endemic geckos at a landscape level; and (ii) to investigate the effects of P. grandis on the abundance and risks of extinction of the endemic geckos at a local scale. An ensemble forecasting approach was used to predict the spatial distribution and overlap of P. grandis and the endemic geckos. We used hierarchical binomial mixture models and repeated visual estimate surveys to calculate the abundance of the endemic geckos in sites with and without P. grandis. The predicted range of each species varied from 85 km2 to 376 km2. Sixty percent of the predicted range of P. grandis overlapped with the combined predicted ranges of the four endemic geckos; 15% of the combined predicted ranges of the four endemic geckos overlapped with P. grandis. Levin's niche breadth varied from 0.140 to 0.652 between P. grandis and the four endemic geckos. The abundance of endemic geckos was 89% lower in sites with P. grandis compared to sites without P. grandis, and the endemic geckos had been extirpated at four of ten sites we surveyed with P. grandis. Species Distribution Modelling, together with the breadth metrics, predicted that P. grandis can partly share the equivalent niche with endemic species and survive in a range of environmental conditions. We provide strong evidence that smaller endemic geckos are unlikely to survive in sympatry with P. grandis. This is a cause of concern in both Mauritius and other countries with endemic species of Phelsuma.
-
The binary projection and overlap between Phelsuma grandis and four endemic species of Phelsuma.
2014Co-Authors: Steeves Buckland, Laura E Gallagher, Sion M Henshaw, Aurelien Besnard, Rachel M Tucker, Vishnu Bachraz, Kevin Ruhomaun, Nik C. Cole, Jesús Aguirre-gutiérrez, Stephen HarrisAbstract:Each map shows the overlap of P. grandis and one of the endemic species. On each map, grey indicates that no species of Phelsuma were predicted to be present, yellow shows the predicted range of Phelsuma grandis, blue the predicted range of that species of endemic Phelsuma, and red areas of predicted overlap between the two species. The first number in each heading is the % overlap of the predicted range of Phelsuma grandis with that species of endemic gecko and the second number is the % overlap of the endemic species' predicted range with that of Phelsuma grandis. The different maps suggest that Phelsuma cepediana (a) and Phelsuma ornata (c) will overlap more with Phelsuma grandis and thus could be at greater risk.
Glaw Frank - One of the best experts on this subject based on the ideXlab platform.
-
FIGURE 4 in Deciphering the cryptic species diversity of dull-coloured day geckos Phelsuma (Squamata: Gekkonidae) from Madagascar, with description of a new species
2011Co-Authors: Crottini Angelica, Glaw Frank, Gehring Philip-sebastian, Harris James, Lima Alexandra, Vences MiguelAbstract:FIGURE 4. Bayesian inference tree based on 358 bp of the mitochondrial 16S rRNA gene. Phelsuma standingi was used as an outgroup. Values at nodes are bootstrap values in percent from MP analyses; values below 70% not shown. Asterisks denote Bayesian posterior probabilities values: (*), 90–94%; *, 95–98%; **, 99–100%. Numbers 1, 2 and 3 denote the three major clades identified within the analysed samples of P. mutabilis
-
FIGURE 5. A in Deciphering the cryptic species diversity of dull-coloured day geckos Phelsuma (Squamata: Gekkonidae) from Madagascar, with description of a new species
2011Co-Authors: Crottini Angelica, Glaw Frank, Gehring Philip-sebastian, Harris James, Lima Alexandra, Vences MiguelAbstract:FIGURE 5. A possible individual of Phelsuma gouldi from near Betroka in life, photo by Hans-Peter Berghof
-
Figure 8 from: Hawlitschek O, Brückmann B, Berger J, Green K, Glaw F (2011) Integrating field surveys and remote sensing data to study distribution, habitat use and conservation status of the herpetofauna of the Comoro Islands. ZooKeys 144: 21-79. https://doi.org/10.3897/zookeys.144.1648
2011Co-Authors: Hawlitschek Oliver, Brückmann Boris, Berger Johannes, Green Katie, Glaw FrankAbstract:Figure 8 - Species photographs. A. Phelsuma nigristriata, Mayotte B Phelsuma comorensis, Grand Comoro C Phelsuma pasteuri, Mayotte D Phelsuma v-nigra anjouanensis, Anjouan E Phelsuma v-nigra comoraegrandensis, Grand Comoro F Phelsuma v-nigra v-nigra, Mohéli G Ebenavia inunguis, ZSM 68/2010, Anjouan H Paroedura sanctijohannis, ZSM 98/2010, Mayotte
-
Figure 18 from: Hawlitschek O, Brückmann B, Berger J, Green K, Glaw F (2011) Integrating field surveys and remote sensing data to study distribution, habitat use and conservation status of the herpetofauna of the Comoro Islands. ZooKeys 144: 21-79. https://doi.org/10.3897/zookeys.144.1648
2011Co-Authors: Hawlitschek Oliver, Brückmann Boris, Berger Johannes, Green Katie, Glaw FrankAbstract:Figure 18 - Distribution maps, and distribution over habitat and altitude classes, for Phelsuma v-nigra, Ramphotyphlops braminus and Trachylepis comorensis
-
FIGURE 6 in Phylogenetic systematics of day geckos, genus Phelsuma, based on molecular and morphological data (Squamata: Gekkonidae)
2010Co-Authors: Rocha Sara, Glaw Frank, Gehring Philip-sebastian, Harris James, Rösler Herbert, Posada David, Vences MiguelAbstract:FIGURE 6. BI tree of available sequences of a fragment of the 16S rRNA gene in specimens of the Phelsuma madagascariensis group. Branches in bold are supported by PP values of 100; other relevant PP values above 50 are given as numbers
Laura E Gallagher - One of the best experts on this subject based on the ideXlab platform.
-
Ecological Effects of the Invasive Giant Madagascar Day Gecko on Endemic Mauritian Geckos: Applications of Binomial-Mixture and Species Distribution Models
2020Co-Authors: Stephen Harris, Steeves Buckland, Laura E Gallagher, N C Cole, J Aguirre-gutiérrez, Besnard, A. .. S M HenshawAbstract:Buckland, S.; Cole, N.C.; Aguirre Gutierrez, J.; Gallagher, L.E.; Henshaw, S.M.; Besnard, A.; Tucker, R.M.; Bachraz, V.; Ruhomaun, K.; Harris, S. Published in: PLoS ONE DOI: 10.1371/journal.pone.0088798 Link to publication Citation for published version (APA): Buckland, S., Cole, N. C., Aguirre-Gutiérrez, J., Gallagher, L. E., Henshaw, S. M., Besnard, A., ... Harris, S. (2014) General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Abstract The invasion of the giant Madagascar day gecko Phelsuma grandis has increased the threats to the four endemic Mauritian day geckos (Phelsuma spp.) that have survived on mainland Mauritius. We had two main aims: (i) to predict the spatial distribution and overlap of P. grandis and the endemic geckos at a landscape level; and (ii) to investigate the effects of P. grandis on the abundance and risks of extinction of the endemic geckos at a local scale. An ensemble forecasting approach was used to predict the spatial distribution and overlap of P. grandis and the endemic geckos. We used hierarchical binomial mixture models and repeated visual estimate surveys to calculate the abundance of the endemic geckos in sites with and without P. grandis. The predicted range of each species varied from 85 km 2 to 376 km 2 . Sixty percent of the predicted range of P. grandis overlapped with the combined predicted ranges of the four endemic geckos; 15% of the combined predicted ranges of the four endemic geckos overlapped with P. grandis. Levin's niche breadth varied from 0.140 to 0.652 between P. grandis and the four endemic geckos. The abundance of endemic geckos was 89% lower in sites with P. grandis compared to sites without P. grandis, and the endemic geckos had been extirpated at four of ten sites we surveyed with P. grandis. Species Distribution Modelling, together with the breadth metrics, predicted that P. grandis can partly share the equivalent niche with endemic species and survive in a range of environmental conditions. We provide strong evidence that smaller endemic geckos are unlikely to survive in sympatry with P. grandis. This is a cause of concern in both Mauritius and other countries with endemic species of Phelsuma
-
High Risks of Losing Genetic Diversity in an Endemic Mauritian Gecko: Implications for Conservation
2016Co-Authors: Steeves Buckl, Laura E Gallagher, Nik C. Cole, Jim J. Groombridge, Terry Burke, Deborah A. Dawson, Stephen HarrisAbstract:Genetic structure can be a consequence of recent population fragmentation and isolation, or a remnant of historical localised adaptation. This poses a challenge for conservationists since misinterpreting patterns of genetic structure may lead to inappropriate management. Of 17 species of reptile originally found in Mauritius, only five survive on the main island. One of these, Phelsuma guimbeaui (lowland forest day gecko), is now restricted to 30 small isolated subpopulations following severe forest fragmentation and isolation due to human colonisation. We used 20 microsatellites in ten subpopulations and two mitochondrial DNA (mtDNA) markers in 13 subpopulations to: (i) assess genetic diversity, population structure and genetic differentiation of subpopulations; (ii) estimate effective population sizes and migration rates of subpopulations; and (iii) examine the phylogenetic relationships of haplotypes found in different subpopulations. Microsatellite data revealed significant population structure with high levels of genetic diversity and isolation by distance, substantial genetic differentiation and no migration between most subpopulations. MtDNA, however, showed no evidence of population structure, indicating that there was once a genetically panmictic population. Effective population sizes of ten subpopulations, based on microsatellite markers, were small, ranging from 44 to 167. Simulations suggested that the chance of survival and allelic diversity of some subpopulations will decrease dramatically over the next 50 years if no migration occurs. Our DNA-based evidence reveals an urgent need for a management plan for the conservation of P
-
Ecological Effects of the Invasive Giant Madagascar Day Gecko on Endemic Mauritian Geckos: Applications of Binomial-Mixture and Species Distribution Models
2015Co-Authors: Steeves Buckl, Laura E Gallagher, Sion M Henshaw, Rachel M Tucker, Vishnu Bachraz, Kevin Ruhomaun, Nik C. Cole, Stephen HarrisAbstract:The invasion of the giant Madagascar day gecko Phelsuma grandis has increased the threats to the four endemic Mauritian day geckos (Phelsuma spp.) that have survived on mainland Mauritius. We had two main aims: (i) to predict the spatial distribution and overlap of P. grandis and the endemic geckos at a landscape level; and (ii) to investigate the effects of P. grandis on the abundance and risks of extinction of the endemic geckos at a local scale. An ensemble forecasting approach was used to predict the spatial distribution and overlap of P. grandis and the endemic geckos. We used hierarchical binomial mixture models and repeated visual estimate surveys to calculate the abundance of the endemic geckos in sites with and without P. grandis. The predicted range of each species varied from 85 km2 to 376 km2. Sixty percent of the predicted range of P. grandis overlapped with the combined predicted ranges of the four endemic geckos; 15 % of the combined predicted ranges of the four endemic geckos overlapped with P. grandis. Levin’s niche breadth varied from 0.140 to 0.652 between P. grandis and the four endemic geckos. The abundance of endemic geckos was 89 % lower in sites with P. grandis compared to sites without P. grandis, and the endemic geckos had been extirpated at four of ten sites we surveyed with P. grandis. Species Distribution Modelling, together with the breadth metrics, predicted that P. grandis can partly share the equivalen
-
ecological effects of the invasive giant madagascar day gecko on endemic mauritian geckos applications of binomial mixture and species distribution models
PLOS ONE, 2014Co-Authors: Steeves Buckland, Nik Cole, Jesus Aguirregutierrez, Laura E Gallagher, Sion M Henshaw, Aurelien Besnard, Rachel M Tucker, Vishnu Bachraz, Kevin Ruhomaun, Stephen HarrisAbstract:The invasion of the giant Madagascar day gecko Phelsuma grandis has increased the threats to the four endemic Mauritian day geckos (Phelsuma spp.) that have survived on mainland Mauritius. We had two main aims: (i) to predict the spatial distribution and overlap of P. grandis and the endemic geckos at a landscape level; and (ii) to investigate the effects of P. grandis on the abundance and risks of extinction of the endemic geckos at a local scale. An ensemble forecasting approach was used to predict the spatial distribution and overlap of P. grandis and the endemic geckos. We used hierarchical binomial mixture models and repeated visual estimate surveys to calculate the abundance of the endemic geckos in sites with and without P. grandis. The predicted range of each species varied from 85 km2 to 376 km2. Sixty percent of the predicted range of P. grandis overlapped with the combined predicted ranges of the four endemic geckos; 15% of the combined predicted ranges of the four endemic geckos overlapped with P. grandis. Levin's niche breadth varied from 0.140 to 0.652 between P. grandis and the four endemic geckos. The abundance of endemic geckos was 89% lower in sites with P. grandis compared to sites without P. grandis, and the endemic geckos had been extirpated at four of ten sites we surveyed with P. grandis. Species Distribution Modelling, together with the breadth metrics, predicted that P. grandis can partly share the equivalent niche with endemic species and survive in a range of environmental conditions. We provide strong evidence that smaller endemic geckos are unlikely to survive in sympatry with P. grandis. This is a cause of concern in both Mauritius and other countries with endemic species of Phelsuma.
-
The binary projection and overlap between Phelsuma grandis and four endemic species of Phelsuma.
2014Co-Authors: Steeves Buckland, Laura E Gallagher, Sion M Henshaw, Aurelien Besnard, Rachel M Tucker, Vishnu Bachraz, Kevin Ruhomaun, Nik C. Cole, Jesús Aguirre-gutiérrez, Stephen HarrisAbstract:Each map shows the overlap of P. grandis and one of the endemic species. On each map, grey indicates that no species of Phelsuma were predicted to be present, yellow shows the predicted range of Phelsuma grandis, blue the predicted range of that species of endemic Phelsuma, and red areas of predicted overlap between the two species. The first number in each heading is the % overlap of the predicted range of Phelsuma grandis with that species of endemic gecko and the second number is the % overlap of the endemic species' predicted range with that of Phelsuma grandis. The different maps suggest that Phelsuma cepediana (a) and Phelsuma ornata (c) will overlap more with Phelsuma grandis and thus could be at greater risk.