T. P. Van, B. Leprince, Hongzhuan Xuan, Quyen Nguyen Thu, O. Duc, Cédric Bordes, M. V. Tien, L. Luiselli
Asian box turtles (genus Cuora; Geoemydidae) are among the most threatened Asian turtles. Here, we present (i) a field investigation from 2014-2018 on the Cuora individuals traded by high-level traders in six provinces of Vietnam and (ii) the estimated numbers of traded individuals determined through interviews with traders. In addition, we (iii) provide an analysis of the confiscated individuals that were carried out at the main wildlife rescue centre of the Socialist Republic of Vietnam. Overall, the number of traded individuals observed was relatively small (n = 481), with C. bourreti being by far the most frequently observed in trade. During the same period, the interviewed traders estimated that about 3,400 individuals were traded through the period 2014-2018, most of them being C. bourreti. During 2010-2018, a total of 281 individuals were carried to the wildlife rescue centre, with over 60 % of the total rescued individuals being C. galbinifrons. Overall, the numbers of traded Cuora individuals recorded in the present study were very small compared to the huge estimates from other Asian countries. However, this lower traded number does not imply that the status’ of the target species are not affected, as their population sizes are already catastrophically reduced in Vietnam.
{"title":"Observations of threatened Asian box turtles (Cuora spp.)\u0000on trade in Vietnam","authors":"T. P. Van, B. Leprince, Hongzhuan Xuan, Quyen Nguyen Thu, O. Duc, Cédric Bordes, M. V. Tien, L. Luiselli","doi":"10.33256/HJ29.3.173178","DOIUrl":"https://doi.org/10.33256/HJ29.3.173178","url":null,"abstract":"Asian box turtles (genus Cuora; Geoemydidae) are among the most threatened Asian turtles. Here, we present (i) a field investigation from 2014-2018 on the Cuora individuals traded by high-level traders in six provinces of Vietnam and (ii) the estimated numbers of traded individuals determined through interviews with traders. In addition, we (iii) provide an analysis of the confiscated individuals that were carried out at the main wildlife rescue centre of the Socialist Republic of Vietnam. Overall, the number of traded individuals observed was relatively small (n = 481), with C. bourreti being by far the most frequently observed in trade. During the same period, the interviewed traders estimated that about 3,400 individuals\u0000were traded through the period 2014-2018, most of them being C. bourreti. During 2010-2018, a total of 281 individuals were carried to the wildlife rescue centre, with over 60 % of the total rescued individuals being C. galbinifrons. Overall, the numbers of traded Cuora individuals recorded in the present study were very small compared to the huge estimates from\u0000other Asian countries. However, this lower traded number does not imply that the status’ of the target species are not affected, as their population sizes are already catastrophically reduced in Vietnam.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48927687","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}
Herpetological research involving amphibians is increasingly using mark and recapture methods, employing various techniques such as toe-clipping and visible implant alphanumeric tags. Visual Implant Elastomer (VIE) is a new method available for herpetological surveys, involving a coloured dye inserted into the epidermal skin surface of frogs. Previously, there has been only one study which demonstrated that the VIE method does not generate a significant physiological stress response (using a faecal glucocorticoid method) in a captive amphibian species. Physiological stress can also be quantified non-invasively using urinary corticosterone metabolite (UCM) enzyme-immunoassay in amphibians. In this study, we tested the physiological stress response of a common amphibian species, wild caught Asian toads (Duttaphrynus melanostictus), by comparing UCM responses to capture handling, sham control or VIE marking method. Adult males (n = 38) were captured and sampled for baseline UCM (t = 0 h) then marked either using the VIE or sham (saline control), or only handled during capture. Subsequently, urine samples were collected at t = 2, 12 and 24 h for toads within each group. UCM levels were quantified using an enzyme immunoassay (EIA) to determine differences among treatment groups and over time following capture. Toads generated acute stress responses to all three groups, showing a change in UCMs between baseline samples, 12 h, and 24 h samples. The mean UCM levels were not significantly different between the VIE method and the control groups (capture handling or sham operated). These results indicate that VIE method of tagging is no more stressful than routine handling of amphibians, hence in this context, the method does not have any additional welfare implications. Future research should explore the limitations of VIE tagging for long-term mark recapture studies, however, our current findings support its application as a minimally-invasive method for marking amphibians.
{"title":"Urinary corticosterone metabolite responses to capture and visual elastomer tagging in the Asian toad (Duttaphrynus melanostictus)","authors":"E. Narayan, N. P. Gramapurohit","doi":"10.33256/HJ29.3.179183","DOIUrl":"https://doi.org/10.33256/HJ29.3.179183","url":null,"abstract":"Herpetological research involving amphibians is increasingly using mark and recapture methods, employing various techniques such as toe-clipping and visible implant alphanumeric tags. Visual Implant Elastomer (VIE) is a new method available for herpetological surveys, involving a coloured dye inserted into the epidermal skin surface of frogs. Previously, there has been only one study which demonstrated that the VIE method does not generate a significant physiological stress response (using a faecal glucocorticoid method) in a captive amphibian species. Physiological stress can also be quantified non-invasively using urinary corticosterone metabolite (UCM) enzyme-immunoassay in amphibians. In this study, we tested the physiological stress response of a common amphibian species, wild caught Asian toads (Duttaphrynus melanostictus), by comparing UCM responses to capture handling, sham control or VIE marking method. Adult males (n = 38) were captured and sampled for baseline UCM (t = 0 h) then marked either using the VIE or sham (saline control), or only handled during capture. Subsequently, urine samples were collected at t = 2, 12 and 24 h for toads within each group. UCM levels were quantified using an enzyme immunoassay (EIA) to determine differences among treatment groups and over time following capture. Toads generated acute stress responses to all three groups, showing a change in UCMs between baseline samples, 12 h, and 24 h samples. The mean UCM levels were not significantly different between the VIE method and the control groups (capture handling or sham operated). These results indicate that VIE method of tagging is no more stressful than routine handling of amphibians, hence in this context, the method does not have any additional welfare implications. Future research should explore the limitations of VIE tagging for long-term mark recapture studies, however, our current findings support its application as a minimally-invasive method for marking amphibians.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47957387","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}
E. Ruíz-Sánchez, G. Arnaud, Oscar Roberto Cruz-Andrés, F. León
The islands of the Gulf of California are divided into three categories – oceanic, continental, and landbridge – and were formed from the Middle Miocene to the Holocene. The species of the Crotalus genus are an important ecological element of the endemic fauna of these islands. This study is the first to include several island-endemic species in a phylogenetic framework. We seek to understand the phylogenetic relationships among these species, and in particular, whether these species are more related to the Baja California peninsula or continental Mexican species, and whether the divergence times for these relationships are consistent with the formation of the islands. We performed a phylogenetic analysis and estimated divergence times using Bayesian inference and two mitochondrial 12S and 16S genes. The analyses show a new relationship between Crotalus angelensis and C. pyrrhus. Crotalus lorenzoensis was nested with C. ruber individuals, making this species a paraphyletic species. A novel relationship was also detected in that C. estebanensis was sister to C. basiliscus. The divergence time for all island-endemic Crotalus species is consistent with the formation of these islands. In addition, the insular species are related to their congeners in the Baja California peninsula or mainland Mexico.
{"title":"Phylogenetic relationships and origin of the rattlesnakes of the Gulf of California islands (Viperidae: Crotalinae: Crotalus)","authors":"E. Ruíz-Sánchez, G. Arnaud, Oscar Roberto Cruz-Andrés, F. León","doi":"10.33256/HJ29.3.162172","DOIUrl":"https://doi.org/10.33256/HJ29.3.162172","url":null,"abstract":"The islands of the Gulf of California are divided into three categories – oceanic, continental, and landbridge – and were formed from the Middle Miocene to the Holocene. The species of the Crotalus genus are an important ecological element of the endemic fauna of these islands. This study is the first to include several island-endemic species in a phylogenetic framework. We seek to understand the phylogenetic relationships among these species, and in particular, whether these species are more related to the Baja California peninsula or continental Mexican species, and whether the divergence times for these relationships are consistent with the formation of the islands. We performed a phylogenetic analysis and estimated divergence times using Bayesian inference and two mitochondrial 12S and 16S genes. The analyses show a new relationship between Crotalus angelensis and C. pyrrhus. Crotalus lorenzoensis was nested with C. ruber individuals, making this species a\u0000paraphyletic species. A novel relationship was also detected in that C. estebanensis was sister to C. basiliscus. The divergence time for all island-endemic Crotalus species is consistent with the formation of these islands. In addition, the insular species are related to their congeners in the Baja California peninsula or mainland Mexico.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43767138","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}
Ricardo Figueroa-Huitrón, H. A. Pérez-Mendoza, A. Vega-Pérez, F. M. L. Cruz, L. Ochoa-Ochoa
Hertz et al. (1993) designed what is now the most widely used protocol to analyse the thermal strategies and efficiency of small squamates. Preferred temperature range (Tp) is one of the most important variables required for determining the thermal efficiency index, and is calculated by monitoring the body temperature of the individuals in an enclosure containing a thermal gradient. Although thermoregulation studies of lizards have traditionally employed thermal gradients under laboratory conditions, this approach is not suitable for snakes given that such thermal gradients do not accurately represent their natural thermal environment and thus may result in snakes selecting suboptimal temperatures. Here, we compare the results of this thermal efficiency protocol using a laboratory thermal gradient (LG) and a semi-captivity thermal gradient (SCG) in the rattlesnake Crotalus polystictus. We found traces of seasonal variation in the SCG Tp, but this could not be assessed in the LG. Tp from the LG was much higher (29 – 34.3 °C) than from the SCG (22.5-30.9 °C). Values for the accuracy of thermoregulation (db) and thermal quality of the environment (de) indices from the LG were consistently higher than from the SCG. However, the efficiency of thermoregulation (E) was higher when calculated from the SCG. Tp estimates were wider than most that have been obtained from other snake species, suggesting that C. polystictus is eurythermic. The Blowin Demers and Weatherhead index was nearly identical in both gradients. Results from the LG indicated that C. polystictus is an inaccurate and inefficient thermoregulator, due to the higher temperatures chosen in this environment. In contrast, results from the SCG suggested that it is a highly accurate and active thermoregulator. We suggest that the LG could represent a stressful environment for snakes, and, as a consequence, they might select higher temperatures to increase anti-predatory performance at the expense of less efficient thermoregulation. Generally, a thermal gradient that more accurately replicates the natural habitat of snake species should reduce stress and result in more robust estimates of thermoregulatory variables.
{"title":"The effect of thermal gradient design on the evaluation of\u0000thermoregulation in snakes","authors":"Ricardo Figueroa-Huitrón, H. A. Pérez-Mendoza, A. Vega-Pérez, F. M. L. Cruz, L. Ochoa-Ochoa","doi":"10.33256/HJ29.3.138145","DOIUrl":"https://doi.org/10.33256/HJ29.3.138145","url":null,"abstract":"Hertz et al. (1993) designed what is now the most widely used protocol to analyse the thermal strategies and efficiency of small squamates. Preferred temperature range (Tp) is one of the most important variables required for determining the thermal efficiency index, and is calculated by monitoring the body temperature of the individuals in an enclosure containing a thermal gradient. Although thermoregulation studies of lizards have traditionally employed thermal gradients under laboratory conditions, this approach is not suitable for snakes given that such thermal gradients do not accurately represent their natural thermal environment and thus may result in snakes selecting suboptimal temperatures. Here, we compare\u0000the results of this thermal efficiency protocol using a laboratory thermal gradient (LG) and a semi-captivity thermal gradient (SCG) in the rattlesnake Crotalus polystictus. We found traces of seasonal variation in the SCG Tp, but this could not be assessed in the LG. Tp from the LG was much higher (29 – 34.3 °C) than from the SCG (22.5-30.9 °C). Values for the accuracy of thermoregulation (db) and thermal quality of the environment (de) indices from the LG were consistently higher than from the SCG. However, the efficiency of thermoregulation (E) was higher when calculated from the SCG. Tp estimates were wider than most that have been obtained from other snake species, suggesting that C. polystictus is eurythermic. The Blowin Demers and Weatherhead index was nearly identical in both gradients. Results from the LG indicated that C. polystictus is an inaccurate and inefficient thermoregulator, due to the higher temperatures chosen in this environment. In contrast, results from the SCG suggested that it is a highly accurate and active thermoregulator. We suggest that the LG could represent a stressful environment for snakes, and, as a consequence, they might select higher temperatures to increase anti-predatory performance at the expense of less efficient thermoregulation. Generally, a thermal gradient that more accurately replicates the natural habitat of snake species should reduce stress and result in more robust estimates of thermoregulatory variables.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42803573","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}
Sozos N. Michaelides, N. Gilbert, Brian E Smith, G. White, A. Hailey, J. Kolbe
Human activities have reshaped patterns of island biogeography for many groups of amphibians and reptiles. In Trinidad, an island in the West Indies with only one native Anolis lizard species, four additional anole species have been introduced since the 1800s. The most recent introduction, Anolis wattsi, native to Antigua, has become established despite the presence of multiple species of resident anoles. We used genetic data (mitochondrial DNA) to infer the geographic origin and genetic structure of introduced A. wattsi on Trinidad. We then gathered published data to compare eco-morphological traits of all anole species currently established on the island. We found three mtDNA haplotypes in Trinidad that clustered with two different clades from the northern part of the native range in Antigua, rejecting the hypothesis that the lizards originated in the pineapple-growing region of the south. However, a lack of fine-scale population structure precluded precise identification of the origin in Antigua of haplotypes introduced to Trinidad. Compared to the other anole species on Trinidad, A. wattsi is smaller, perches lower, and has a higher field body temperature. Thus, the successful establishment and spread of A. wattsi should not be surprising given the success of two previous introductions of anole species that were more similar ecomorphologically to the native species and each other, and the fact that Trinidad has relatively few anole species for its size.
{"title":"Genetic reconstruction of the invasion history of Anolis\u0000wattsi in Trinidad with a comment on the importance of ecological\u0000similarity to invasion success","authors":"Sozos N. Michaelides, N. Gilbert, Brian E Smith, G. White, A. Hailey, J. Kolbe","doi":"10.33256/HJ29.3.131137","DOIUrl":"https://doi.org/10.33256/HJ29.3.131137","url":null,"abstract":"Human activities have reshaped patterns of island biogeography for many groups of amphibians and reptiles. In Trinidad, an island in the West Indies with only one native Anolis lizard species, four additional anole species have been introduced since the 1800s. The most recent introduction, Anolis wattsi, native to Antigua, has become established despite the presence of\u0000multiple species of resident anoles. We used genetic data (mitochondrial DNA) to infer the geographic origin and genetic structure of introduced A. wattsi on Trinidad. We then gathered published data to compare eco-morphological traits of all anole species currently established on the island. We found three mtDNA haplotypes in Trinidad that clustered with two\u0000different clades from the northern part of the native range in Antigua, rejecting the hypothesis that the lizards originated in the pineapple-growing region of the south. However, a lack of fine-scale population structure precluded precise identification of the origin in Antigua of haplotypes introduced to Trinidad. Compared to the other anole species on Trinidad, A. wattsi is smaller, perches lower, and has a higher field body temperature. Thus, the successful establishment and spread of A. wattsi should not be surprising given the success of two previous introductions of anole species that were more similar ecomorphologically to the native species and each other, and the fact that Trinidad has relatively few anole species for its size.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45233060","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}
Lizards show a great variety of visual displays. Among them, arm-waving is a behaviour that has received little attention and its role is still ontroversial. Here, I analyse the armwaves of Liolaemus pacha lizards in their natural habitat with the aim of determining their function. Arm-waving was performed by both sexes, usually with the ventral body surface in contact with the ground. Furthermore, it was more frequent when alone, and during female-male interactions. The results of this study are suggestive but not conclusive regarding the possible function of this behaviour.
{"title":"Arm-wave display in a Liolaemus lizard","authors":"Natalin Vicente","doi":"10.33256/HJ29.3.184188","DOIUrl":"https://doi.org/10.33256/HJ29.3.184188","url":null,"abstract":"Lizards show a great variety of visual displays. Among them, arm-waving is a behaviour that has received little attention and its role is still ontroversial. Here, I analyse the armwaves of Liolaemus pacha lizards in their natural habitat with the aim of determining their function. Arm-waving was performed by both sexes, usually with the ventral body surface in contact with the ground. Furthermore, it was more frequent when alone, and during female-male interactions. The results of this study are suggestive but not conclusive regarding the possible function of this behaviour.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42212649","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}
Iván Beltrán, Valeria Ramírez-Castañeda, Camilo Rodríguez-López, E. Lasso, A. Amézquita
Environmental temperature has fitness consequences on ectotherm development, ecology and behaviour. Amphibians are especially vulnerable because thermoregulation often trades with appropriate water balance. Although substantial research has evaluated the effect of temperature in amphibian locomotion and physiological limits, there is little information about amphibians living under extreme temperature conditions. Leptodactylus lithonaetes is a frog allegedly specialised to forage and breed on dark granitic outcrops and associated puddles, which reach environmental temperatures well above 40 ˚C. Adults can select thermally favourable microhabitats during the day while tadpoles are constrained to rock puddles and associated temperature fluctuations; we thus established microhabitat temperatures and tested whether the critical thermal maximum (CTmax) of L. lithonaetes is higher in tadpoles compared to adults. In addition, we evaluated the effect of water temperature on locomotor performance of tadpoles. Contrary to our expectations, puddle temperatures were comparable and even lower than those temperatures measured in the microhabitats used by adults in the daytime. Nonetheless, the CTmax was 42.3 ˚C for tadpoles and 39.7 ˚C for adults. Regarding locomotor performance, maximum speed and maximum distance travelled by tadpoles peaked around 34 ˚C, approximately 1 ˚C below the maximum puddle temperatures registered in the puddles. In conclusion, L. lithonaetes tadpoles have a higher CTmax compared to adults, suggesting a longer exposure to extreme temperatures that lead to maintain their physiological performance at high temperatures. We suggest that these conditions are adaptations to face the strong selection forces driven by this granitic habitat.
{"title":"Dealing with hot rocky environments: Critical thermal maxima and locomotor performance in Leptodactylus lithonaetes (Anura: Leptodactylidae)","authors":"Iván Beltrán, Valeria Ramírez-Castañeda, Camilo Rodríguez-López, E. Lasso, A. Amézquita","doi":"10.33256/HJ29.3.155161","DOIUrl":"https://doi.org/10.33256/HJ29.3.155161","url":null,"abstract":"Environmental temperature has fitness consequences on ectotherm development, ecology and behaviour. Amphibians are especially vulnerable because thermoregulation often trades with appropriate water balance. Although substantial research has evaluated the effect of temperature in amphibian locomotion and physiological limits, there is little information about amphibians living under extreme temperature conditions. Leptodactylus lithonaetes is a frog allegedly specialised to forage and breed on dark granitic outcrops and associated puddles, which reach environmental temperatures well above 40 ˚C. Adults can select thermally favourable microhabitats during the day while tadpoles are constrained to rock puddles and associated temperature fluctuations; we thus established microhabitat temperatures and tested whether the critical thermal maximum (CTmax) of L. lithonaetes is higher in tadpoles compared to adults. In addition, we evaluated the effect of water temperature on locomotor performance of tadpoles. Contrary to our expectations, puddle temperatures were comparable and even lower than those temperatures measured in the microhabitats used by adults in the daytime. Nonetheless, the CTmax was 42.3 ˚C for tadpoles and 39.7 ˚C for adults. Regarding locomotor performance, maximum speed and maximum distance travelled by tadpoles peaked around 34 ˚C, approximately 1 ˚C below the maximum puddle temperatures registered in the puddles. In conclusion, L. lithonaetes tadpoles have a higher CTmax compared to adults, suggesting a longer exposure to extreme temperatures that lead to maintain their physiological performance at high temperatures. We suggest that these conditions are adaptations to face the strong selection forces driven by this granitic habitat.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43700873","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}
Holly L. Baines, B. Gini, Yu-Mei Chang, C. Michaels
Dominance is a key component of behaviour in many animal species and is central to social system dynamics, resource acquisition, individual fitness and ultimately reproductive success. We investigated dominance interactions and social behaviours in a group of captive juvenile gidgee skinks (Egernia stokesii). We hypothesised that a dominance hierarchy existed within the group, and that aggressive behaviours would be used to secure limited resources, especially high-value resources. We also hypothesised that body weight would be positively correlated with dominance and aggressive behaviours. We filmed the lizards at 1200 hours for six days a week over the course of eight weeks. We exposed the lizards to three different diets, which consisted of an animal-based diet (crickets), plant-based diet (plants), and a non-feeding control (no food offered). The relative value of these resources to the skinks was established through preference tests. We identified a dominance hierarchy, with dominant individuals exhibiting more aggressive behaviours than subordinates. We found that the frequency of aggressive behaviours was significantly higher in trials where high-valued resources (crickets) were at stake. Furthermore, we found a significant positive correlation between body weight and dominance, bite and chase; larger individuals were ranked higher in the social hierarchy compared to smaller individuals. Our results demonstrate the importance of morphological and behavioural traits in determining a dominance hierarchy in E. stokesii and how dominance can have ecological advantages.
{"title":"Dominance and aggression in captive gidgee skinks (Egernia stokesii)","authors":"Holly L. Baines, B. Gini, Yu-Mei Chang, C. Michaels","doi":"10.33256/hj30.2.8392","DOIUrl":"https://doi.org/10.33256/hj30.2.8392","url":null,"abstract":"Dominance is a key component of behaviour in many animal species and is central to social system dynamics, resource acquisition, individual fitness and ultimately reproductive success. We investigated dominance interactions and social behaviours in a group of captive juvenile gidgee skinks (Egernia stokesii). We hypothesised that a dominance hierarchy existed within the group, and that aggressive behaviours would be used to secure limited resources, especially high-value resources. We also hypothesised that body weight would be positively correlated with dominance and aggressive behaviours. We filmed the lizards at 1200 hours for six days a week over the course of eight weeks. We exposed the lizards to three different diets, which consisted of an animal-based diet (crickets), plant-based diet (plants), and a non-feeding control (no food offered). The relative value of these resources to the skinks was established through preference tests. We identified a dominance hierarchy, with dominant individuals exhibiting more aggressive behaviours than subordinates. We found that the frequency of aggressive behaviours was significantly higher in trials where high-valued resources (crickets) were at stake. Furthermore, we found a significant positive correlation between body weight and dominance, bite and chase; larger individuals were ranked higher in the social hierarchy compared to smaller individuals. Our results demonstrate the importance of morphological and behavioural traits in determining a dominance hierarchy in E. stokesii and how dominance can have ecological advantages.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44154288","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}
Procuring offspring from captive animals can be important for research and conservation efforts. Yet, reliable methods for obtaining fertilised eggs are unavailable for many species. In this study, we examined the efficacy of one drug, leuprolide acetate, to induce reproduction (i.e. egg production, tadpole hatching) in the northern leopard frog, Rana pipiens. We found that leuprolide acetate successfully induced breeding and larval development in animals that were overwintered in the lab, but not in animals caught during the breeding season. These results indicate that leuprolide acetate can be successful in inducing breeding and fertilisation of frog eggs, but that its effectiveness might be contingent upon length of time in captivity and the animals having undergone an artificial overwintering period in the laboratory prior to induction. Artificial breeding success is species and context dependent; therefore, identifying additional methods effective across taxa will help support species in need of management intervention.
{"title":"Artificial reproduction using leuprolide acetate in the frog\u0000Rana pipiens","authors":"L. Brannelly, M. Ohmer, C. Richards‐Zawacki","doi":"10.33256/HJ29.2.125130","DOIUrl":"https://doi.org/10.33256/HJ29.2.125130","url":null,"abstract":"Procuring offspring from captive animals can be important for research and conservation efforts. Yet, reliable methods for obtaining fertilised eggs are unavailable for many species. In this study, we examined the efficacy of one drug, leuprolide acetate, to induce reproduction (i.e. egg production, tadpole hatching) in the northern leopard frog, Rana pipiens. We found that leuprolide acetate successfully induced breeding and larval development in animals that were overwintered in the lab, but not in animals caught during the breeding season. These results indicate that leuprolide acetate can be successful in inducing breeding and fertilisation of frog eggs, but that its effectiveness might be contingent upon length of time in captivity and the animals having undergone an artificial overwintering period in the laboratory prior to induction. Artificial breeding success is species and context dependent; therefore, identifying additional methods effective across taxa will help support species in need of management intervention.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43878471","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}
A 35-year (1967–2002) demographic study was conducted on the gopher tortoise (Gopherus polyphemus) from two different habitats on Archbold Biological Station located on the southern end of the Lake Wales Ridge in south-central Florida. We found geographic, habitat, and human-mediated effects on several aspects of its biology. Our findings underscore the necessity of long-term demographic data to more accurately answer ecological questions concerning long-lived species, such as how the gopher tortoise detectably might be affected by habitat quality and human activities.
{"title":"The effects of geography, habitat, and humans on the ecology and demography of the Gopher tortoise in the southern Lake Wales Ridge region of Florida","authors":"W. Meshaka, J. Layne, Kenneth G. Rice","doi":"10.33256/HJ29.2.95114","DOIUrl":"https://doi.org/10.33256/HJ29.2.95114","url":null,"abstract":"A 35-year (1967–2002) demographic study was conducted on the gopher tortoise (Gopherus polyphemus) from two different habitats on Archbold Biological Station located on the southern end of the Lake Wales Ridge in south-central Florida. We found geographic, habitat, and human-mediated effects on several aspects of its biology. Our findings underscore the necessity of long-term demographic data to more accurately answer ecological questions concerning long-lived species, such as how the\u0000gopher tortoise detectably might be affected by habitat quality and human activities.","PeriodicalId":56131,"journal":{"name":"Herpetological Journal","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48055169","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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