Dear Editor,Life-history studies including dietary preferences and trophic interactions are essential for understanding community ecology in lizards(Pianka,1986).The family Agamidae is one of the largest in terms of s...Dear Editor,Life-history studies including dietary preferences and trophic interactions are essential for understanding community ecology in lizards(Pianka,1986).The family Agamidae is one of the largest in terms of species diversity and occurs in a variety of habitats(Uetz et al.,2024).展开更多
Nigeria is an Afrotropical region with considerable ecological heterogeneity and levels of biotic endemism.Among its vertebrate fauna,reptiles have broad distributions,thus,they constitute a compelling system for asse...Nigeria is an Afrotropical region with considerable ecological heterogeneity and levels of biotic endemism.Among its vertebrate fauna,reptiles have broad distributions,thus,they constitute a compelling system for assessing the impact of ecological variation and geographic isolation on species diversification.The red-headed rock agama,Agama agama,lives in a wide range of habitats and,thus,it may show genetic structuring and diversification.Herein,we tested the hypothesis that ecology affects its genetic structure and population divergence.Bayesian inference phylogenetic analysis of a mitochondrial DNA(mtDNA)gene recovered four well-supported matrilines with strong evidence of genetic structuring consistent with eco-geographic regions.Genetic differences among populations based on the mtDNA also correlated with geographic distance. The ecologicalniche model for the matrilines had a good fit and robust performance. Population divergence alongthe environmental axes was associated with climatic conditions, and temperature ranked highestamong all environmental variables for forest specialists, while precipitation ranked highest for theforest/derived savanna, and savanna specialists. Our results cannot reject the hypothesis that nicheconservatism promotes geographic isolation of the western populations of Nigerian A. agama.Thus, ecological gradients and geographic isolation impact the genetic structure and population divergenceof the lizards. This species might be facing threats due to recent habitat fragmentation,especially in western Nigeria. Conservation actions appear necessary.展开更多
The pattern that many ectotherms have smaller body sizes in coM environments follows the converse to Bergmann＇s rule and is most frequently found in lizards. Allen＇s rule predicts animals from warm climates usually ...The pattern that many ectotherms have smaller body sizes in coM environments follows the converse to Bergmann＇s rule and is most frequently found in lizards. Allen＇s rule predicts animals from warm climates usually have longer tails and limbs, while these traits tend to be shorter in individuals from cold climates. We examined body size variation in an endemic Chinese lizard Phrynocephalus theobaldi along a broad elevational gradient （3,600-5,000 m on the Qinghai-Tibetan Plateau）. Female body size showed a U-shaped cline, decreasing with increased elevation within the range 3,600-4,200 m, but increasing at eleva- tions 〉 4200 m. Male body size continued to increase with increasing elevations. Both sexes showed an increased pattern of ex- tremity length with elevation that does not conform to Allen＇s rule. Limb length and tail length increased along the elevational gradients. In terms of color pattern, an abdominal black speckled area appears at elevations 〉4,200 m. This trait increases in size with increased elevation. Unlike most studies, our results indicated that annual sunshine hours corresponding to the activity pe- riod of the lizards could play an important role on the positive body size cline in environments at very high elevations 〉 4200 m展开更多
The sole voucher of Papenfuss＇ Rock Agama, Laudakia papenfussi （CIB 775001）, an adult male, was collected from Zanda, Tibet, China on July 1, 1976 and described in 1998. No information on this species appeared sinc...The sole voucher of Papenfuss＇ Rock Agama, Laudakia papenfussi （CIB 775001）, an adult male, was collected from Zanda, Tibet, China on July 1, 1976 and described in 1998. No information on this species appeared since its description. In September 2014, we collected one female and six males at the type locality. Based on the original description and these newly collected specimens, we re-describe this species. Principal components analysis based on 33 morphological characteristics clearly diagnose L. papenfussi from closely related species. One way ANOVA test shows significant differences among four Tibetan rock agamas for 9 characters at 95% significant level, and 8 characters at 99% significant level. Molecular analyses recover three main clades in Laudakia. The four Tibetan rock agamas place into two geographical groups： Yarlung Zangbo group （L. sacra and L. wui） and the Himalayan group （L. tuberculata and L. papenfussi）.展开更多
To understand the effects of sand grain size on habitat selection, we conducted a field study on the steppe toad-headed lizard in Hunshandake Desert northern China. Methods of mark-recapture and transect survey were u...To understand the effects of sand grain size on habitat selection, we conducted a field study on the steppe toad-headed lizard in Hunshandake Desert northern China. Methods of mark-recapture and transect survey were used to investigate the density of steppe toad-headed lizards and the environmental variables. The comparison on lizard densities among the habitats with different environmental factors revealed that： 1） population density of the steppe toad-headed lizard differed significantly among the habitats with different sand grain size indexes（SGSIs, representing roughness of sand substrate）： the highest lizard density was found in the group with an SGSI of 〉 0.30, whereas the lowest density was found in the group with an SGSI of 0–0.15; and 2） vegetation cover, soil moisture, invertebrate diversity index, and abundance had no significant effects on the lizard density. These results implied that the sand grain size was the most important determinant of habitat selection for steppe toad-headed lizards in Hunshandake Desert. Steppe toad-headed lizards could avoid structural habitats that have negative effects on their maximal sprinting capabilities. Considering the changing sand grain size in the development phase of sand dunes, the sand lizard could be used as an indicator of the process of desertification.展开更多
文摘Dear Editor,Life-history studies including dietary preferences and trophic interactions are essential for understanding community ecology in lizards(Pianka,1986).The family Agamidae is one of the largest in terms of species diversity and occurs in a variety of habitats(Uetz et al.,2024).
文摘Nigeria is an Afrotropical region with considerable ecological heterogeneity and levels of biotic endemism.Among its vertebrate fauna,reptiles have broad distributions,thus,they constitute a compelling system for assessing the impact of ecological variation and geographic isolation on species diversification.The red-headed rock agama,Agama agama,lives in a wide range of habitats and,thus,it may show genetic structuring and diversification.Herein,we tested the hypothesis that ecology affects its genetic structure and population divergence.Bayesian inference phylogenetic analysis of a mitochondrial DNA(mtDNA)gene recovered four well-supported matrilines with strong evidence of genetic structuring consistent with eco-geographic regions.Genetic differences among populations based on the mtDNA also correlated with geographic distance. The ecologicalniche model for the matrilines had a good fit and robust performance. Population divergence alongthe environmental axes was associated with climatic conditions, and temperature ranked highestamong all environmental variables for forest specialists, while precipitation ranked highest for theforest/derived savanna, and savanna specialists. Our results cannot reject the hypothesis that nicheconservatism promotes geographic isolation of the western populations of Nigerian A. agama.Thus, ecological gradients and geographic isolation impact the genetic structure and population divergenceof the lizards. This species might be facing threats due to recent habitat fragmentation,especially in western Nigeria. Conservation actions appear necessary.
基金Acknowledgments This work was supported by the National Natural Science Foundation of China （31372183, 31000950）. We thank the Chinese National Climate Data Center for his- torical climatic data, and the Tibetan government for permis- sion to collect specimens. We thank R. Brown, S. Mullin for their kind detailed reviews on the manuscript before submis- sion, and appreciate R. Brown for his extensive help in im- proving the language of the manuscript before publication. We also thank S. Meiri and another anonymous referee for their kind revisions or suggestions on our submitted manuscript.
文摘The pattern that many ectotherms have smaller body sizes in coM environments follows the converse to Bergmann＇s rule and is most frequently found in lizards. Allen＇s rule predicts animals from warm climates usually have longer tails and limbs, while these traits tend to be shorter in individuals from cold climates. We examined body size variation in an endemic Chinese lizard Phrynocephalus theobaldi along a broad elevational gradient （3,600-5,000 m on the Qinghai-Tibetan Plateau）. Female body size showed a U-shaped cline, decreasing with increased elevation within the range 3,600-4,200 m, but increasing at eleva- tions 〉 4200 m. Male body size continued to increase with increasing elevations. Both sexes showed an increased pattern of ex- tremity length with elevation that does not conform to Allen＇s rule. Limb length and tail length increased along the elevational gradients. In terms of color pattern, an abdominal black speckled area appears at elevations 〉4,200 m. This trait increases in size with increased elevation. Unlike most studies, our results indicated that annual sunshine hours corresponding to the activity pe- riod of the lizards could play an important role on the positive body size cline in environments at very high elevations 〉 4200 m
基金supported by grants from the Ministry of Science and Technology of China(2014FY210200,2011FY120200)State Key Laboratory of Genetic Resources and Evolution,Kunming Institute of Zoology,CAS(GREKF13-10)+1 种基金the Animal Branch of the Germplasm Bank of Wild Species of Chinese Academy of Sciences(the Large Research Infrastructure Funding)the National Natural Science Foundation of China(NSFC 31060280)
文摘The sole voucher of Papenfuss＇ Rock Agama, Laudakia papenfussi （CIB 775001）, an adult male, was collected from Zanda, Tibet, China on July 1, 1976 and described in 1998. No information on this species appeared since its description. In September 2014, we collected one female and six males at the type locality. Based on the original description and these newly collected specimens, we re-describe this species. Principal components analysis based on 33 morphological characteristics clearly diagnose L. papenfussi from closely related species. One way ANOVA test shows significant differences among four Tibetan rock agamas for 9 characters at 95% significant level, and 8 characters at 99% significant level. Molecular analyses recover three main clades in Laudakia. The four Tibetan rock agamas place into two geographical groups： Yarlung Zangbo group （L. sacra and L. wui） and the Himalayan group （L. tuberculata and L. papenfussi）.
基金financial support of the Key Basic Science and Technology Project of the Ministry of Science and Technology, China (2013FY110300)the National Natural Science Foundation of China (No. 31572260)the Knowledge Innovation Project of the Chinese Academy of Sciences (KSCX2-EW-J-2)
文摘To understand the effects of sand grain size on habitat selection, we conducted a field study on the steppe toad-headed lizard in Hunshandake Desert northern China. Methods of mark-recapture and transect survey were used to investigate the density of steppe toad-headed lizards and the environmental variables. The comparison on lizard densities among the habitats with different environmental factors revealed that： 1） population density of the steppe toad-headed lizard differed significantly among the habitats with different sand grain size indexes（SGSIs, representing roughness of sand substrate）： the highest lizard density was found in the group with an SGSI of 〉 0.30, whereas the lowest density was found in the group with an SGSI of 0–0.15; and 2） vegetation cover, soil moisture, invertebrate diversity index, and abundance had no significant effects on the lizard density. These results implied that the sand grain size was the most important determinant of habitat selection for steppe toad-headed lizards in Hunshandake Desert. Steppe toad-headed lizards could avoid structural habitats that have negative effects on their maximal sprinting capabilities. Considering the changing sand grain size in the development phase of sand dunes, the sand lizard could be used as an indicator of the process of desertification.
