Pub Date : 2021-11-16DOI: 10.2994/SAJH-D-19-00122.1
Jane C. F. Oliveira, Á. Ferreguetti, Thiago Marcial de Castro, C. F. Duarte Rocha
Abstract. The sandy coastal plains of Brazil are one of the most threatened ecosystems of the Atlantic Forest domain, due primarily to habitat suppression and fragmentation. Glaucomastix littoralis is a threatened endemic lizard that was found to have a declining population in a previous study. Our principal hypothesis in the present study is that altered habitats are less likely to be occupied by G. littoralis due to the elimination of conditions favorable to this species. We tested this hypothesis by analyzing which habitat variables determine abundance, occurrence, and detectability of G. littoralis, comparing populations from six different sites representing different levels of conservation in sandy coastal habitats (restinga) in northern Rio de Janeiro state. We used Royle–Nichols occupancy models to estimate the abundance of G. littoralis and single-species multi-scale occupancy models to estimate its detectability and spatial distribution. The location of the transect was the covariate that best explained the abundance of G. littoralis. The estimated population size for the whole area was 265 individuals, and the estimated mean abundance per transect was = 18 ± 3. Occupancy by G. littoralis was higher in transects with regenerating vegetation. We found a positive relationship between large-scale occupancy rates and the distance of the transect from the nearest human settlement. Detectability was affected by air temperature and was higher at sites with deeper leaf litter and in sandy microhabitats. Site occupancy by G. littoralis was also higher at sites with deeper leaf litter. Our findings indicate that the modification of Brazilian restinga habitats could drive G. littoralis to extinction.
{"title":"Factors Affecting the Abundance and Occurrence of a Threatened Whiptail Lizard Endemic to the Sandy Coastal Plains of Brazil","authors":"Jane C. F. Oliveira, Á. Ferreguetti, Thiago Marcial de Castro, C. F. Duarte Rocha","doi":"10.2994/SAJH-D-19-00122.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-19-00122.1","url":null,"abstract":"Abstract. The sandy coastal plains of Brazil are one of the most threatened ecosystems of the Atlantic Forest domain, due primarily to habitat suppression and fragmentation. Glaucomastix littoralis is a threatened endemic lizard that was found to have a declining population in a previous study. Our principal hypothesis in the present study is that altered habitats are less likely to be occupied by G. littoralis due to the elimination of conditions favorable to this species. We tested this hypothesis by analyzing which habitat variables determine abundance, occurrence, and detectability of G. littoralis, comparing populations from six different sites representing different levels of conservation in sandy coastal habitats (restinga) in northern Rio de Janeiro state. We used Royle–Nichols occupancy models to estimate the abundance of G. littoralis and single-species multi-scale occupancy models to estimate its detectability and spatial distribution. The location of the transect was the covariate that best explained the abundance of G. littoralis. The estimated population size for the whole area was 265 individuals, and the estimated mean abundance per transect was = 18 ± 3. Occupancy by G. littoralis was higher in transects with regenerating vegetation. We found a positive relationship between large-scale occupancy rates and the distance of the transect from the nearest human settlement. Detectability was affected by air temperature and was higher at sites with deeper leaf litter and in sandy microhabitats. Site occupancy by G. littoralis was also higher at sites with deeper leaf litter. Our findings indicate that the modification of Brazilian restinga habitats could drive G. littoralis to extinction.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"21 1","pages":"25 - 33"},"PeriodicalIF":0.9,"publicationDate":"2021-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49515883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-01DOI: 10.2994/SAJH-D-18-00045.1
L. Martins, L. E. Costa-Schmidt, A. M. Garcia, R. F. Bastos, M. M. Rebelato, A. M. Tozetti
Abstract. Trophic subsidy is an ecological process consisting in the transference of nutrients between adjacent habitats, allowing the occupancy of less productive habitats by several species. We tested for the existence of trophic subsidy provided by aquatic plants of temporary ponds in maintaining individuals of the sand dune lizard Liolaemus occipitalis in southern Brazil. This lizard is a sit-and-wait predator restricted to coastal sand dunes. As these sand dunes occur in a mosaic of temporary ponds, we hypothesized the existence of a nutritional/energetic dependence of lizards from adjacent aquatic habitats. Our evaluation was based on carbon and nitrogen stable isotope analysis in association with gut content analysis of lizards sampled along an entire inundation cycle. Stomach contents revealed no seasonal variation in consumed prey item composition. Nevertheless, we detected changes in prey group composition. The volumetric contribution of Diptera increased over inundation classes (increase = 5%; peak = 61%). Carbon and nitrogen stable isotope ratios indicated that the L. occipitalis trophic web is mainly maintained by terrestrial sources. Isotope ratios also indicated the existence of aquatic contributions to tissue formation, but, despite its tendency to increase over the inundation process (10.7–13.3%), this trend lacks statistical support. We conclude that the studied population of L. occipitalis partially depends on trophic subsidy from aquatic sources and that any conservation plan for this endangered lizard species should take into account the preservation of non-habitats like temporary ponds.
{"title":"The Contribution of Aquatic Plants to the Trophic Ecology of a Sand Dune Lizard in Southern Brazil","authors":"L. Martins, L. E. Costa-Schmidt, A. M. Garcia, R. F. Bastos, M. M. Rebelato, A. M. Tozetti","doi":"10.2994/SAJH-D-18-00045.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-18-00045.1","url":null,"abstract":"Abstract. Trophic subsidy is an ecological process consisting in the transference of nutrients between adjacent habitats, allowing the occupancy of less productive habitats by several species. We tested for the existence of trophic subsidy provided by aquatic plants of temporary ponds in maintaining individuals of the sand dune lizard Liolaemus occipitalis in southern Brazil. This lizard is a sit-and-wait predator restricted to coastal sand dunes. As these sand dunes occur in a mosaic of temporary ponds, we hypothesized the existence of a nutritional/energetic dependence of lizards from adjacent aquatic habitats. Our evaluation was based on carbon and nitrogen stable isotope analysis in association with gut content analysis of lizards sampled along an entire inundation cycle. Stomach contents revealed no seasonal variation in consumed prey item composition. Nevertheless, we detected changes in prey group composition. The volumetric contribution of Diptera increased over inundation classes (increase = 5%; peak = 61%). Carbon and nitrogen stable isotope ratios indicated that the L. occipitalis trophic web is mainly maintained by terrestrial sources. Isotope ratios also indicated the existence of aquatic contributions to tissue formation, but, despite its tendency to increase over the inundation process (10.7–13.3%), this trend lacks statistical support. We conclude that the studied population of L. occipitalis partially depends on trophic subsidy from aquatic sources and that any conservation plan for this endangered lizard species should take into account the preservation of non-habitats like temporary ponds.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"21 1","pages":"12 - 24"},"PeriodicalIF":0.9,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41737672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-01DOI: 10.2994/SAJH-D-18-00086.1
M. Rodriguez-Muñoz, G. Blanco, J. C. Acosta, T. Martínez
Abstract. The objective of this study was to describe and compare the reproductive cycle of Pleurodema tucumanum in dry and rainy years in a portion of the Chaco Serrano in western Argentina. We captured 141 males and 93 females during their months of activity between 2011 and 2015. Adults were sexed and their body size and weight were determined. We weighed fat bodies and calculated testis volume in males and fecundity in females. Fecundity was based on the number of mature oocytes present in the ovary, the ovarian complement. Like many species of the family Leptodactylidae, this species presents sexual dimorphism, with females being larger than males. The reproductive variables showed no significant differences between dry and rainy years. Linear regression analyses between abiotic factors (maximum temperature, minimum temperature, and accumulated rainfall) and reproductive variables showed significant positive relationships. Both in dry and rainy years, we recorded the presence of atretic follicles and developing and maturing oviducts. In rainy years, mature oocytes were observed from November through April, and from October to March in dry years (local summer). Only in dry years were significant variations observed in fat body weight during the reproductive season. Annual cycles of rainy periods do not affect the reproductive activity of this species, which appears to be a strategy for its permanence in this Chacoan region.
{"title":"Effects of Annual Rainfall on Reproduction of Pleurodema tucumanum (Anura: Leptodactylidae) on the Western Border of the Great American Chaco","authors":"M. Rodriguez-Muñoz, G. Blanco, J. C. Acosta, T. Martínez","doi":"10.2994/SAJH-D-18-00086.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-18-00086.1","url":null,"abstract":"Abstract. The objective of this study was to describe and compare the reproductive cycle of Pleurodema tucumanum in dry and rainy years in a portion of the Chaco Serrano in western Argentina. We captured 141 males and 93 females during their months of activity between 2011 and 2015. Adults were sexed and their body size and weight were determined. We weighed fat bodies and calculated testis volume in males and fecundity in females. Fecundity was based on the number of mature oocytes present in the ovary, the ovarian complement. Like many species of the family Leptodactylidae, this species presents sexual dimorphism, with females being larger than males. The reproductive variables showed no significant differences between dry and rainy years. Linear regression analyses between abiotic factors (maximum temperature, minimum temperature, and accumulated rainfall) and reproductive variables showed significant positive relationships. Both in dry and rainy years, we recorded the presence of atretic follicles and developing and maturing oviducts. In rainy years, mature oocytes were observed from November through April, and from October to March in dry years (local summer). Only in dry years were significant variations observed in fat body weight during the reproductive season. Annual cycles of rainy periods do not affect the reproductive activity of this species, which appears to be a strategy for its permanence in this Chacoan region.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"21 1","pages":"1 - 11"},"PeriodicalIF":0.9,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41895691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-31DOI: 10.2994/SAJH-D-18-00016.1
T. Maia-Carneiro, T. Dorigo, M. C. Kiefer, M. van Sluys, C. F. Duarte Rocha
Abstract. We investigated daily activity, microhabitat use, and feeding habits of the anuran Adenomera marmorata in two Brazilian Atlantic forest remnants: Estação Ecológica Estadual Paraíso (EEEP) and Reserva Ecológica de Guapiaçu (REGUA). Most individuals were active at dusk (EEEP: n = 5 or 62.5%; REGUA: n = 16 or 45.7%; populations pooled: n = 21 or 48.8%) and nocturnally (EEEP: n = 3 or 37.5%; REGUA: n = 17 or 48.6%; populations pooled: n = 20 or 46.5%); however, individuals were encountered during the day (EEEP: n = 0; REGUA: n = 2 or 5.7%; populations pooled: n = 2 or 4.7%). The microhabitat used most by the anurans was the leaf litter of forest floor (EEEP: n = 8 or 80.0%; REGUA: n = 33 or 94.3%; populations pooled: n = 41 or 91.1%). In EEEP, in numerical terms, mainly isopods (33.33%) and ants (22.22%) composed the diet of A. marmorata. Volumetrically, Isopoda (77.37%) was the most important item. In terms of frequency of occurrence, isopods, and ants, both consumed by 30% of the individuals, were the most relevant food items. In REGUA, numerically, individuals mainly consumed ants (23.26%) and isopods (20.93%). In volumetric terms, individuals predominantly ingested isopods (56.57%). The food items most commonly consumed by individuals in REGUA were isopods (40.63%) and ants (37.50%). Adenomera marmorata ingested 8 different types of food in EEEP and 14 in REGUA, feeding on a significantly higher number of food items in REGUA than in EEEP. The populations also differed in diet composition in volumetric terms, showing that food consumption can vary between populations, which might result from differences in local food availability and individual morphological characteristics. Adenomera marmorata might be able to forage opportunistically or selectively depending on the prey.
{"title":"Feeding Habits, Microhabitat Use, and Daily Activity Cycle of Adenomera marmorata (Anura, Leptodactylidae) in Two Brazilian Atlantic Forest Remnants","authors":"T. Maia-Carneiro, T. Dorigo, M. C. Kiefer, M. van Sluys, C. F. Duarte Rocha","doi":"10.2994/SAJH-D-18-00016.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-18-00016.1","url":null,"abstract":"Abstract. We investigated daily activity, microhabitat use, and feeding habits of the anuran Adenomera marmorata in two Brazilian Atlantic forest remnants: Estação Ecológica Estadual Paraíso (EEEP) and Reserva Ecológica de Guapiaçu (REGUA). Most individuals were active at dusk (EEEP: n = 5 or 62.5%; REGUA: n = 16 or 45.7%; populations pooled: n = 21 or 48.8%) and nocturnally (EEEP: n = 3 or 37.5%; REGUA: n = 17 or 48.6%; populations pooled: n = 20 or 46.5%); however, individuals were encountered during the day (EEEP: n = 0; REGUA: n = 2 or 5.7%; populations pooled: n = 2 or 4.7%). The microhabitat used most by the anurans was the leaf litter of forest floor (EEEP: n = 8 or 80.0%; REGUA: n = 33 or 94.3%; populations pooled: n = 41 or 91.1%). In EEEP, in numerical terms, mainly isopods (33.33%) and ants (22.22%) composed the diet of A. marmorata. Volumetrically, Isopoda (77.37%) was the most important item. In terms of frequency of occurrence, isopods, and ants, both consumed by 30% of the individuals, were the most relevant food items. In REGUA, numerically, individuals mainly consumed ants (23.26%) and isopods (20.93%). In volumetric terms, individuals predominantly ingested isopods (56.57%). The food items most commonly consumed by individuals in REGUA were isopods (40.63%) and ants (37.50%). Adenomera marmorata ingested 8 different types of food in EEEP and 14 in REGUA, feeding on a significantly higher number of food items in REGUA than in EEEP. The populations also differed in diet composition in volumetric terms, showing that food consumption can vary between populations, which might result from differences in local food availability and individual morphological characteristics. Adenomera marmorata might be able to forage opportunistically or selectively depending on the prey.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"20 1","pages":"100 - 105"},"PeriodicalIF":0.9,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49181873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-21DOI: 10.2994/SAJH-D-19-00114.1
J. Erickson, Francisco Raphael Pereira, F. Baccaro
Abstract. Competition and facilitation are opposite sides of the species-interaction continuum. However, competitive interactions between species could result in facilitation for a third species. We evaluated the patterns of infestation and competitive exclusion between crazy-ants (Nylanderia sp.1) and fire-ants (Solenopsis geminata) and their effect on yellow-spotted Amazon River turtle (Podocnemis unifilis) nests in central Amazonia. We found that Nylanderia sp.1 colonizes P. unifilis nests at the start of their incubation period, whereas S. geminata was more abundant in nests during the final third of the incubation period. After colonization, the ant colonies remained in the nest through the breeding season. We did not observe differences in hatching success between nests with or without Nylanderia sp.1; however, in all nests colonized by S. geminata the entire P. unifilis clutch was lost. Our results suggest that during the incubation period, P. unifilis clutches benefit from Nylanderia sp.1 colonization, which prevents nest colonization by S. geminata. During the most defenseless stage in the life history of turtles, indirect facilitation by Nylanderia sp.1 appears to support the coexistence between prey, P. unifilis clutches, and their main predator, S. geminata, during the incubation period.
{"title":"Competitive Interaction between Two Ant Species Facilitates Egg Hatching in Yellow-Spotted Amazon River Turtles (Podocnemis unifilis)","authors":"J. Erickson, Francisco Raphael Pereira, F. Baccaro","doi":"10.2994/SAJH-D-19-00114.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-19-00114.1","url":null,"abstract":"Abstract. Competition and facilitation are opposite sides of the species-interaction continuum. However, competitive interactions between species could result in facilitation for a third species. We evaluated the patterns of infestation and competitive exclusion between crazy-ants (Nylanderia sp.1) and fire-ants (Solenopsis geminata) and their effect on yellow-spotted Amazon River turtle (Podocnemis unifilis) nests in central Amazonia. We found that Nylanderia sp.1 colonizes P. unifilis nests at the start of their incubation period, whereas S. geminata was more abundant in nests during the final third of the incubation period. After colonization, the ant colonies remained in the nest through the breeding season. We did not observe differences in hatching success between nests with or without Nylanderia sp.1; however, in all nests colonized by S. geminata the entire P. unifilis clutch was lost. Our results suggest that during the incubation period, P. unifilis clutches benefit from Nylanderia sp.1 colonization, which prevents nest colonization by S. geminata. During the most defenseless stage in the life history of turtles, indirect facilitation by Nylanderia sp.1 appears to support the coexistence between prey, P. unifilis clutches, and their main predator, S. geminata, during the incubation period.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"20 1","pages":"84 - 91"},"PeriodicalIF":0.9,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69931857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-21DOI: 10.2994/SAJH-D-19-00111.1
L. S. de Gregorio, L. Franco‐Belussi, C. de Oliveira
Abstract. Amphibians are threatened with extinction worldwide, and one of the global causes is environmental pollution. Several toxicants can interfere with their immune system, making them more susceptible to disease, which also contributes to their decline. The contaminants 4-nonylphenol (NP), a detergent with estrogenic properties, and cyproterone acetate (CPA), an anti-androgenic medicine, are known to impair the immune system of some vertebrates, but the effects are understudied in anurans. In this study, we evaluated the effects of NP (at 1, 10, and 100 µg/L) and CPA (at 0.025, 0.25, and 2.5 ng/L) on leukocyte count in tadpoles and juveniles of Lithobates catesbeianus. We analyzed lymphocytes, neutrophils, basophils, eosinophils, monocytes, and thrombocytes in a proportional count and made comparisons between the groups. The experiments lasted 28 d, and the conditions were almost identical for both stages (varying only the volume of water). The tadpoles showed decreased lymphocytes and increased neutrophils at 1 µg/L NP and increased eosinophils at the two highest doses of CPA. The juveniles showed reduced neutrophils in all treatments with both compounds and increased thrombocytes (except at 2.5 ng/L CPA). Also, all dosages of CPA increased basophils. Although the life-stages had different response patterns, our study showed that NP and CPA altered the proportion of leukocytes on blood stream in both stages, probably as a response against the negative effects of the compounds, which might make the animals more susceptible to diseases and contribute to their decline.
{"title":"Leukocyte Profile of Tadpoles and Juveniles of Lithobates catesbeianus Shaw, 1802 (Anura) and the Effects of Nonylphenol and Cyproterone Acetate","authors":"L. S. de Gregorio, L. Franco‐Belussi, C. de Oliveira","doi":"10.2994/SAJH-D-19-00111.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-19-00111.1","url":null,"abstract":"Abstract. Amphibians are threatened with extinction worldwide, and one of the global causes is environmental pollution. Several toxicants can interfere with their immune system, making them more susceptible to disease, which also contributes to their decline. The contaminants 4-nonylphenol (NP), a detergent with estrogenic properties, and cyproterone acetate (CPA), an anti-androgenic medicine, are known to impair the immune system of some vertebrates, but the effects are understudied in anurans. In this study, we evaluated the effects of NP (at 1, 10, and 100 µg/L) and CPA (at 0.025, 0.25, and 2.5 ng/L) on leukocyte count in tadpoles and juveniles of Lithobates catesbeianus. We analyzed lymphocytes, neutrophils, basophils, eosinophils, monocytes, and thrombocytes in a proportional count and made comparisons between the groups. The experiments lasted 28 d, and the conditions were almost identical for both stages (varying only the volume of water). The tadpoles showed decreased lymphocytes and increased neutrophils at 1 µg/L NP and increased eosinophils at the two highest doses of CPA. The juveniles showed reduced neutrophils in all treatments with both compounds and increased thrombocytes (except at 2.5 ng/L CPA). Also, all dosages of CPA increased basophils. Although the life-stages had different response patterns, our study showed that NP and CPA altered the proportion of leukocytes on blood stream in both stages, probably as a response against the negative effects of the compounds, which might make the animals more susceptible to diseases and contribute to their decline.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"20 1","pages":"75 - 83"},"PeriodicalIF":0.9,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44341294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-21DOI: 10.2994/SAJH-D-19-00117.1
L. H. Siqueira, K. Banci, O. A. Marques
Abstract. The peak of activity of Bothrops jararaca is in the rainy season. This pitviper feeds mainly on small mammals and is preyed upon by several avian and mammal predators. However, the association between jararaca's seasonal activity with that of their prey and predators remains unknown. The present study tested the hypothesis that the peak activity of B. jararaca coincides with that of their prey and predators, mainly due to favorable climatic conditions during this period. Snake activity was inferred from standardized searches and animals deposited in herpetological collections. Seasonal activity of prey was inferred from monthly sampling carried out over one year using pitfall and Sherman traps. Plasticine models were used to infer predation risk. Analyses of predator and prey abundance were performed, taking into account climatic variables, and models explaining this relationship were proposed. Activity of both B. jararaca and its prey was higher in the rainy season. Activity of the latter was positively correlated with temperature and rainfall. Predator activity, however, was higher in the dry season and negatively correlated with temperature and rainfall but positively correlated with humidity. The peak activity of B. jararaca in the rainy season might favor foraging activities, since this period coincides with greater prey abundance and decreased predation risk. During the dry season when resource availability is low, predators feed opportunistically, encountering dangerous prey such as B. jararaca. In summary, the activity pattern showed by the snake clearly increases its survival.
{"title":"Seasonal Activity of Bothrops jararaca (Serpentes, Viperidae): Optimizing Foraging while Avoiding Predators","authors":"L. H. Siqueira, K. Banci, O. A. Marques","doi":"10.2994/SAJH-D-19-00117.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-19-00117.1","url":null,"abstract":"Abstract. The peak of activity of Bothrops jararaca is in the rainy season. This pitviper feeds mainly on small mammals and is preyed upon by several avian and mammal predators. However, the association between jararaca's seasonal activity with that of their prey and predators remains unknown. The present study tested the hypothesis that the peak activity of B. jararaca coincides with that of their prey and predators, mainly due to favorable climatic conditions during this period. Snake activity was inferred from standardized searches and animals deposited in herpetological collections. Seasonal activity of prey was inferred from monthly sampling carried out over one year using pitfall and Sherman traps. Plasticine models were used to infer predation risk. Analyses of predator and prey abundance were performed, taking into account climatic variables, and models explaining this relationship were proposed. Activity of both B. jararaca and its prey was higher in the rainy season. Activity of the latter was positively correlated with temperature and rainfall. Predator activity, however, was higher in the dry season and negatively correlated with temperature and rainfall but positively correlated with humidity. The peak activity of B. jararaca in the rainy season might favor foraging activities, since this period coincides with greater prey abundance and decreased predation risk. During the dry season when resource availability is low, predators feed opportunistically, encountering dangerous prey such as B. jararaca. In summary, the activity pattern showed by the snake clearly increases its survival.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"20 1","pages":"67 - 74"},"PeriodicalIF":0.9,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45743459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-21DOI: 10.2994/SAJH-D-19-00105.1
Brian C. Bock, Paula A. Espinal-García, Juan David Silva-Macias, Vivian P. Páez
Abstract. We quantified nesting activity and incidence of nest flooding in a population of the Magdalena River turtle (Podocnemis lewyana), which inhabits the climatic equator in northern Colombia, during two dry seasons when beaches formed (“verano”—December to March—and “veranillo”—July and August). Nesting activity was concentrated in the verano period, despite the presence of suitable nesting habitat in both dry season periods. More than half of all nests were harvested by local people, and 42.5% of the nests in both dry seasons that survived harvest were subsequently lost to flooding due to rises in the river to approximately a 4.15 m level. We used this value as a threshold value for the appearance of beaches and inspected a 44-year data base on river levels in this area. The verano and veranillo nesting periods did not differ in terms of opportunities for successful nesting, but there was evidence that the veranillo nesting season has increased significantly in duration in recent years, as well as experienced fewer flooding events. It is not clear why nesting each year is principally concentrated in the verano nesting season, but the evidence that this section of the Magdalena River is drying more in recent years during veranillo may entail a new threat to this population if it implies that non-nesting habitat (adjacent wetlands and channels) might eventually disappear.
{"title":"Risk of Nest Flooding in a Population of the Magdalena River Turtle (Podocnemis lewyana) Inhabiting the Climatic Equator in Northern Colombia","authors":"Brian C. Bock, Paula A. Espinal-García, Juan David Silva-Macias, Vivian P. Páez","doi":"10.2994/SAJH-D-19-00105.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-19-00105.1","url":null,"abstract":"Abstract. We quantified nesting activity and incidence of nest flooding in a population of the Magdalena River turtle (Podocnemis lewyana), which inhabits the climatic equator in northern Colombia, during two dry seasons when beaches formed (“verano”—December to March—and “veranillo”—July and August). Nesting activity was concentrated in the verano period, despite the presence of suitable nesting habitat in both dry season periods. More than half of all nests were harvested by local people, and 42.5% of the nests in both dry seasons that survived harvest were subsequently lost to flooding due to rises in the river to approximately a 4.15 m level. We used this value as a threshold value for the appearance of beaches and inspected a 44-year data base on river levels in this area. The verano and veranillo nesting periods did not differ in terms of opportunities for successful nesting, but there was evidence that the veranillo nesting season has increased significantly in duration in recent years, as well as experienced fewer flooding events. It is not clear why nesting each year is principally concentrated in the verano nesting season, but the evidence that this section of the Magdalena River is drying more in recent years during veranillo may entail a new threat to this population if it implies that non-nesting habitat (adjacent wetlands and channels) might eventually disappear.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"20 1","pages":"92 - 99"},"PeriodicalIF":0.9,"publicationDate":"2021-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46429624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-10DOI: 10.2994/SAJH-D-18-00082.1
F. Lobo, D. A. Barrasso, T. Hibbard, M. Quipildor, Demian Slodki, S. Valdecantos, N. Basso
Abstract. The Phymaturus payuniae clade is an endemic group of lizards inhabiting rocky outcrops of central western Argentina. All recognized species are found in an area of endemism called “Payunia.” Recent studies using morphological data and DNA markers found that the payuniae clade comprises at least 10 terminal taxa. In the present study, we revisited the morphology of all previously considered terminals and analyzed two new populations discovered in Neuquén province in 2005 and 2016. The revised character list allowed us to score morphological characters for several taxa whose morphologies were unknown prior to this study. In the present study, we sequenced ND4 for three terminals (completing other sequences available for these taxa), and Cytb, COI, 12S, and C-mos for one terminal (for which no DNA data had been reported). We then added these sequences to the pre-existing DNA databases for the genus. We estimated genetic distances for three mitochondrial markers among all members of the clade and calculated the evolutionary lability of morphological characters for the whole patagonicus group. Variation of 26 continuous characters was analyzed with Principal Component Analysis for all members of the payuniae clade and species of other clades of the patagonicus and palluma group. Additionally, we revised genital characters for all members of the group and included a description of the new taxa's hemipenial morphology. Considering the distribution of morphological characters among species, their genetic distances, different genital morphology, and the phylogenetic structure inferred, we are able to support the taxonomic status of all species of the group and add the formal description of two new species.
{"title":"Morphological and Genetic Divergence within the Phymaturus payuniae Clade (Iguania: Liolaemidae), with the Description of Two New Species","authors":"F. Lobo, D. A. Barrasso, T. Hibbard, M. Quipildor, Demian Slodki, S. Valdecantos, N. Basso","doi":"10.2994/SAJH-D-18-00082.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-18-00082.1","url":null,"abstract":"Abstract. The Phymaturus payuniae clade is an endemic group of lizards inhabiting rocky outcrops of central western Argentina. All recognized species are found in an area of endemism called “Payunia.” Recent studies using morphological data and DNA markers found that the payuniae clade comprises at least 10 terminal taxa. In the present study, we revisited the morphology of all previously considered terminals and analyzed two new populations discovered in Neuquén province in 2005 and 2016. The revised character list allowed us to score morphological characters for several taxa whose morphologies were unknown prior to this study. In the present study, we sequenced ND4 for three terminals (completing other sequences available for these taxa), and Cytb, COI, 12S, and C-mos for one terminal (for which no DNA data had been reported). We then added these sequences to the pre-existing DNA databases for the genus. We estimated genetic distances for three mitochondrial markers among all members of the clade and calculated the evolutionary lability of morphological characters for the whole patagonicus group. Variation of 26 continuous characters was analyzed with Principal Component Analysis for all members of the payuniae clade and species of other clades of the patagonicus and palluma group. Additionally, we revised genital characters for all members of the group and included a description of the new taxa's hemipenial morphology. Considering the distribution of morphological characters among species, their genetic distances, different genital morphology, and the phylogenetic structure inferred, we are able to support the taxonomic status of all species of the group and add the formal description of two new species.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"20 1","pages":"42 - 66"},"PeriodicalIF":0.9,"publicationDate":"2021-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48711963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-30DOI: 10.2994/SAJH-D-18-00064.1
Felipe E. Rabanal, C. Úbeda, Camila F. Tejo, E. Lavilla
Abstract. Although the original description of Batrachyla antartandica categorically states that the species should not be considered as arboreal, our field observations show that it has excellent climbing abilities. Associated with this fact, B. antartandica shows an alternative mode of reproduction that involves the use of tree-trunk cavities filled with water as a site for calling, reproduction, development, and metamorphosis. As far as we know, B. antartandica is the only anuran species in the Valdivian temperate rainforests of Chile and Argentina with a completely arboreal life cycle.
{"title":"Tree-Holes as Alternative Reproductive Sites of Batrachyla antartandica Barrio, 1967 (Anura: Batrachylidae)","authors":"Felipe E. Rabanal, C. Úbeda, Camila F. Tejo, E. Lavilla","doi":"10.2994/SAJH-D-18-00064.1","DOIUrl":"https://doi.org/10.2994/SAJH-D-18-00064.1","url":null,"abstract":"Abstract. Although the original description of Batrachyla antartandica categorically states that the species should not be considered as arboreal, our field observations show that it has excellent climbing abilities. Associated with this fact, B. antartandica shows an alternative mode of reproduction that involves the use of tree-trunk cavities filled with water as a site for calling, reproduction, development, and metamorphosis. As far as we know, B. antartandica is the only anuran species in the Valdivian temperate rainforests of Chile and Argentina with a completely arboreal life cycle.","PeriodicalId":48691,"journal":{"name":"South American Journal of Herpetology","volume":"20 1","pages":"24 - 32"},"PeriodicalIF":0.9,"publicationDate":"2021-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44813882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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