Tail autotomy is a defense mechanism used by many lizards to evade predators, but it entails costs. We used the oriental leaf-toed gecko Hemidactylus bowringii as a model animal to evaluate locomotor costs of tail aut...Tail autotomy is a defense mechanism used by many lizards to evade predators, but it entails costs. We used the oriental leaf-toed gecko Hemidactylus bowringii as a model animal to evaluate locomotor costs of tail autotomy. We removed the tail about 5 mm from the tail base from each of the experimental geckos(adult males) initially having intact tails. Tailless experimental geckos and tailed control geckos were measured for overall speed and sprint speed in both vertical and horizontal directions. Overall speed and sprint speed did not differ between tailless and tailed geckos. The influence of locomotor direction on both overall speed and sprint speed was significant, with horizontal speed being greater than vertical speed. The interaction between tail condition and locomotor direction was not significant in overall speed, but was significant in sprint speed. Tailless geckos had faster vertical sprint speed than the tailed individuals. Of the 130 field-caught adults, 59 had previously lost their tails, with most(about 61%) of them shedding their tails near the tail base. Neither the proportion of geckos with tail autotomy nor the frequency distribution of locations of the tail break differed between the sexes. Our data show that tail loss of H. bowringii occurs frequently in nature. However, tail loss does not incur locomotor costs in this gecko.展开更多
In this study, we identified the current distribution of five globally distributed invasive Hemidactylus species and predicted their potential and future distribution using species distribution models based on climate...In this study, we identified the current distribution of five globally distributed invasive Hemidactylus species and predicted their potential and future distribution using species distribution models based on climate and elevation data. These species included H. brookii, H. frenatus, H. garnotii, FI. mabouia, and H. turcicus. We show that many regions with tropical and Mediterranean climates are suitable for most of these species. However, their current and potential distributions sug- gest that climate is not the only limiting factor. We hypothesize that climatic conditions may affect competition and other interactions resulting in a segregated distribution of the studied Hemidactylus species. As an effect of global climate change it is likely that H. brookiiwill expand its range to areas that are currently colonized by H. mabouia and/or H. frenatus, while H. turcicus is likely to expand its range to areas that are not yet invaded by any Hemidactylus species. The role of species interactions in the range expansion of these five Hemidactylus species still remains poorly understood, but could be of major importance in understanding and managing these invasive species.展开更多
House geckos in the genus Hemidactylus are highly successful colonizers of regions beyond their native range,with colonization often resulting in displacement of native gecko species through competitive interactions f...House geckos in the genus Hemidactylus are highly successful colonizers of regions beyond their native range,with colonization often resulting in displacement of native gecko species through competitive interactions for daytime refuge(crevices)and prey resources.We report on data collected from nighttime surveys undertaken in April-May 2014 on Barbados,West Indies,that focused on the distribution and abundance of the endemic Barbados leaf-toed gecko(Phyllodactylus pulcher)and the introduced tropical house gecko(Hemidactylus mabouia)along unlit coastal walls and among boulders in the grounds of a hotel resort.In contrast to patterns of displacement of native species by H.mabouia seen elsewhere,P.pulcher was more abundant than H.mabouia on coastal walls,whereas the latter was found in greater numbers using boulders at this site.Walls and boulders differed with regard to availability of diurnal refugia suitable for geckos,with the walls having high frequency of small crevices with openings<20 mm,and boulders offering very little cover other than the underside of the boulder itself.To investigate whether this niche separation was a result of differences in diurnal refuge use between the species,we conducted experimental trials in which geckos were allowed to select between refugia with different characteristics.Both species selected for narrower and warmer refugia,and refugia that had been previously occupied by the other species.These shared preferences for refugia type suggest that other factors underlie the niche separation observed in the field.In supporting high densities of P.pulcher,coastal walls could offer important secondary habitat by augmenting the natural cliff side habitat of this endemic gecko,a finding that could be exploited for the conservation of this candidate species for Critically Endangered classification.展开更多
Herpetological surveys of locations in six districts of Timor-Leste(Dili, Baucau, Ermera, Liqui a, Manatuto, Viqueque) during 2010 led to the discovery of a new, high-altitude species of Cryptoblepharus from Ermera Di...Herpetological surveys of locations in six districts of Timor-Leste(Dili, Baucau, Ermera, Liqui a, Manatuto, Viqueque) during 2010 led to the discovery of a new, high-altitude species of Cryptoblepharus from Ermera District, a new country record(Hemidactylus cf. tenkatei), and the recording of two previously unvouchered species(Python r. reticulatus and Liasis m. mackloti). In this article, we summarize these new records and present numerous new district records for Timor-Leste and four records for road-killed snakes seen in West Timor(Indonesia). With the addition of the results from our 2009 survey, the update presented herein increases the confirmed number of amphibian and reptile species for Timor-Leste to 47.展开更多
基金supported by grants from Innovative Team Project of Nanjing Normal University(Project No.0319PM0902)Priority Academic Program Development of Jiangsu Higher Education Institutions(CXLX11_0885)to Xiang JI
文摘Tail autotomy is a defense mechanism used by many lizards to evade predators, but it entails costs. We used the oriental leaf-toed gecko Hemidactylus bowringii as a model animal to evaluate locomotor costs of tail autotomy. We removed the tail about 5 mm from the tail base from each of the experimental geckos(adult males) initially having intact tails. Tailless experimental geckos and tailed control geckos were measured for overall speed and sprint speed in both vertical and horizontal directions. Overall speed and sprint speed did not differ between tailless and tailed geckos. The influence of locomotor direction on both overall speed and sprint speed was significant, with horizontal speed being greater than vertical speed. The interaction between tail condition and locomotor direction was not significant in overall speed, but was significant in sprint speed. Tailless geckos had faster vertical sprint speed than the tailed individuals. Of the 130 field-caught adults, 59 had previously lost their tails, with most(about 61%) of them shedding their tails near the tail base. Neither the proportion of geckos with tail autotomy nor the frequency distribution of locations of the tail break differed between the sexes. Our data show that tail loss of H. bowringii occurs frequently in nature. However, tail loss does not incur locomotor costs in this gecko.
文摘In this study, we identified the current distribution of five globally distributed invasive Hemidactylus species and predicted their potential and future distribution using species distribution models based on climate and elevation data. These species included H. brookii, H. frenatus, H. garnotii, FI. mabouia, and H. turcicus. We show that many regions with tropical and Mediterranean climates are suitable for most of these species. However, their current and potential distributions sug- gest that climate is not the only limiting factor. We hypothesize that climatic conditions may affect competition and other interactions resulting in a segregated distribution of the studied Hemidactylus species. As an effect of global climate change it is likely that H. brookiiwill expand its range to areas that are currently colonized by H. mabouia and/or H. frenatus, while H. turcicus is likely to expand its range to areas that are not yet invaded by any Hemidactylus species. The role of species interactions in the range expansion of these five Hemidactylus species still remains poorly understood, but could be of major importance in understanding and managing these invasive species.
文摘House geckos in the genus Hemidactylus are highly successful colonizers of regions beyond their native range,with colonization often resulting in displacement of native gecko species through competitive interactions for daytime refuge(crevices)and prey resources.We report on data collected from nighttime surveys undertaken in April-May 2014 on Barbados,West Indies,that focused on the distribution and abundance of the endemic Barbados leaf-toed gecko(Phyllodactylus pulcher)and the introduced tropical house gecko(Hemidactylus mabouia)along unlit coastal walls and among boulders in the grounds of a hotel resort.In contrast to patterns of displacement of native species by H.mabouia seen elsewhere,P.pulcher was more abundant than H.mabouia on coastal walls,whereas the latter was found in greater numbers using boulders at this site.Walls and boulders differed with regard to availability of diurnal refugia suitable for geckos,with the walls having high frequency of small crevices with openings<20 mm,and boulders offering very little cover other than the underside of the boulder itself.To investigate whether this niche separation was a result of differences in diurnal refuge use between the species,we conducted experimental trials in which geckos were allowed to select between refugia with different characteristics.Both species selected for narrower and warmer refugia,and refugia that had been previously occupied by the other species.These shared preferences for refugia type suggest that other factors underlie the niche separation observed in the field.In supporting high densities of P.pulcher,coastal walls could offer important secondary habitat by augmenting the natural cliff side habitat of this endemic gecko,a finding that could be exploited for the conservation of this candidate species for Critically Endangered classification.
基金Financial assistance for equipment and supplies was partially provided by a Title V Grant to Victor Valley CollegePartial financing of student travel was provided by the Associated Student Body at Victor Valley College
文摘Herpetological surveys of locations in six districts of Timor-Leste(Dili, Baucau, Ermera, Liqui a, Manatuto, Viqueque) during 2010 led to the discovery of a new, high-altitude species of Cryptoblepharus from Ermera District, a new country record(Hemidactylus cf. tenkatei), and the recording of two previously unvouchered species(Python r. reticulatus and Liasis m. mackloti). In this article, we summarize these new records and present numerous new district records for Timor-Leste and four records for road-killed snakes seen in West Timor(Indonesia). With the addition of the results from our 2009 survey, the update presented herein increases the confirmed number of amphibian and reptile species for Timor-Leste to 47.
