Pub Date : 2022-09-20DOI: 10.1163/15685381-bja10101
Dylan Maag, R. Clark
Rattlesnakes are widespread mesopredators that are themselves killed and eaten by a host of other predators, including birds of prey and carnivorous mammals. Although anecdotal accounts of rattlesnake depredation are common, there are few quantitative data on encounter rates between rattlesnakes and their predators. Here we review a large database of encounters between rattlesnakes and their predators recorded from field videography of snakes in the sit-and-wait phase of their ambush hunting strategy. We found that, across 8300 hours of observation, adult rattlesnakes of six species and multiple populations exhibit low encounter rates with predators; furthermore, when predators were encountered, we never observed them to attack or kill coiled snakes. Thus, we propose that rattlesnakes are preyed upon while performing other, riskier behaviors associated with moving through the landscape. We also discuss why rattlesnakes are at low risk of predation while hunting on the surface.
{"title":"Safety in coils: predation rates of ambush hunting rattlesnakes are extremely low","authors":"Dylan Maag, R. Clark","doi":"10.1163/15685381-bja10101","DOIUrl":"https://doi.org/10.1163/15685381-bja10101","url":null,"abstract":"Rattlesnakes are widespread mesopredators that are themselves killed and eaten by a host of other predators, including birds of prey and carnivorous mammals. Although anecdotal accounts of rattlesnake depredation are common, there are few quantitative data on encounter rates between rattlesnakes and their predators. Here we review a large database of encounters between rattlesnakes and their predators recorded from field videography of snakes in the sit-and-wait phase of their ambush hunting strategy. We found that, across 8300 hours of observation, adult rattlesnakes of six species and multiple populations exhibit low encounter rates with predators; furthermore, when predators were encountered, we never observed them to attack or kill coiled snakes. Thus, we propose that rattlesnakes are preyed upon while performing other, riskier behaviors associated with moving through the landscape. We also discuss why rattlesnakes are at low risk of predation while hunting on the surface.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44127546","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 : 2022-09-01DOI: 10.1163/15685381-bja10099
Clara Ribeiro Porto, C. Fazolato, Ricardo Marques, H. Batalha‐Filho, M. Napoli, A. A. Garda, Maria Luiza Silveira de Carvalho, Flora Maria de Campos Fernandes
Many studies on the diversity of the South American biota support the role of ecological and geological events as main drivers of species diversification. For many groups, geomorphological events are the key drivers of diversification, while the influence of Pleistocene climate oscillations is prominent for others. To precisely indicate which events were key for the development of the astonishing biodiversity in South America, studies on widely distributed species are paramount. One such species, the dwarf swamp frog Pseudopaludicola mystacalis (Leptodactylidae, Leiuperinae), is widely distributed in open habitats of South America and we herein investigate population differentiation and diversification in this species across its geographic range. We sequenced a 1374 bp mtDNA fragment from 64 specimens across 25 localities. We used population assignment and species delimitation methods to assess genetic structure and lineage limits across the species distribution. We estimated, for each lineage, intraspecific diversity, divergence times, and demographic histories. Our results recovered ten lineages with up to 5% of genetic divergence among them. Diversification occurred mainly during the Tertiary, suggesting that Miocene-Pliocene topographic events had a major influence on the diversification of P. mystacalis. Pleistocene climatic oscillations also played a role on evolutionary history of P. mystacalis, causing demographic changes in one lineage.
{"title":"Unravelling the cryptic diversity and evolution of the dwarf swamp frog Pseudopaludicola mystacalis (Anura, Leptodactylidae) in open habitats of South America","authors":"Clara Ribeiro Porto, C. Fazolato, Ricardo Marques, H. Batalha‐Filho, M. Napoli, A. A. Garda, Maria Luiza Silveira de Carvalho, Flora Maria de Campos Fernandes","doi":"10.1163/15685381-bja10099","DOIUrl":"https://doi.org/10.1163/15685381-bja10099","url":null,"abstract":"\u0000 Many studies on the diversity of the South American biota support the role of ecological and geological events as main drivers of species diversification. For many groups, geomorphological events are the key drivers of diversification, while the influence of Pleistocene climate oscillations is prominent for others. To precisely indicate which events were key for the development of the astonishing biodiversity in South America, studies on widely distributed species are paramount. One such species, the dwarf swamp frog Pseudopaludicola mystacalis (Leptodactylidae, Leiuperinae), is widely distributed in open habitats of South America and we herein investigate population differentiation and diversification in this species across its geographic range. We sequenced a 1374 bp mtDNA fragment from 64 specimens across 25 localities. We used population assignment and species delimitation methods to assess genetic structure and lineage limits across the species distribution. We estimated, for each lineage, intraspecific diversity, divergence times, and demographic histories. Our results recovered ten lineages with up to 5% of genetic divergence among them. Diversification occurred mainly during the Tertiary, suggesting that Miocene-Pliocene topographic events had a major influence on the diversification of P. mystacalis. Pleistocene climatic oscillations also played a role on evolutionary history of P. mystacalis, causing demographic changes in one lineage.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49454182","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 : 2022-07-19DOI: 10.1163/15685381-bja10097
Graham T. BeVier, Cole Ayton, Kinsey M. Brock
Intraspecific colour morphs usually differ in more traits than just colour. These traits can manifest as differences in morph physiology, behaviour, and ecology. Ecological differences among colour morphs, such as the degree of parasitism, can influence the evolution, maintenance, and loss of morphs from populations. High ectoparasite load can directly and deleteriously impact host fitness, and thus could influence colour morph persistence in populations if certain morphs are more frequently exposed to parasites or are more susceptible to parasitism. The Aegean wall lizard, Podarcis erhardii, is a colour polymorphic island lizard that is parasitized externally by ticks and mites. These ectoparasites can affect aspects of host lizard behaviour and physiology – including thermoregulation and body mass – and therefore are an important factor influencing the ecology and fitness of P. erhardii. We find that among sympatric colour morphs, ectoparasite loads differ; namely, monochromatic orange morphs have the highest numbers of ectoparasites, and in general, morphs with orange alleles (orange, orange-white, and orange-yellow) are more heavily parasitized by ticks and mites than the other morphs. Our results indicate that morphs with orange alleles tend to occupy microhabitats with significantly more vegetation cover and thus may increase their exposure to ticks and mites. Ecological differences between morphs could be an important factor contributing to demonstrated patterns of orange morph rarity and loss in P. erhardii populations.
{"title":"It ain’t easy being orange: lizard colour morphs occupying highly vegetated microhabitats suffer greater ectoparasitism","authors":"Graham T. BeVier, Cole Ayton, Kinsey M. Brock","doi":"10.1163/15685381-bja10097","DOIUrl":"https://doi.org/10.1163/15685381-bja10097","url":null,"abstract":"\u0000Intraspecific colour morphs usually differ in more traits than just colour. These traits can manifest as differences in morph physiology, behaviour, and ecology. Ecological differences among colour morphs, such as the degree of parasitism, can influence the evolution, maintenance, and loss of morphs from populations. High ectoparasite load can directly and deleteriously impact host fitness, and thus could influence colour morph persistence in populations if certain morphs are more frequently exposed to parasites or are more susceptible to parasitism. The Aegean wall lizard, Podarcis erhardii, is a colour polymorphic island lizard that is parasitized externally by ticks and mites. These ectoparasites can affect aspects of host lizard behaviour and physiology – including thermoregulation and body mass – and therefore are an important factor influencing the ecology and fitness of P. erhardii. We find that among sympatric colour morphs, ectoparasite loads differ; namely, monochromatic orange morphs have the highest numbers of ectoparasites, and in general, morphs with orange alleles (orange, orange-white, and orange-yellow) are more heavily parasitized by ticks and mites than the other morphs. Our results indicate that morphs with orange alleles tend to occupy microhabitats with significantly more vegetation cover and thus may increase their exposure to ticks and mites. Ecological differences between morphs could be an important factor contributing to demonstrated patterns of orange morph rarity and loss in P. erhardii populations.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42207021","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 : 2022-07-19DOI: 10.1163/15685381-bja10098
Eleanor G. Tate, Amber L. Pitt, Myles D. Little, Joseph J. Tavano, M. Nickerson
Ecological communities are becoming more typified by generalist species in conjunction with anthropogenic activities. Using a long-term dataset (1968-2019), we documented the expansion of a native generalist species, the red-eared slider (Trachemys scripta elegans), into a river community, and studied the subsequent population changes that occurred in conjunction with short- and long-term changes within the ecosystem. Trachemys scripta elegans was able to expand into a new geographic area following a harvesting-induced population decline of a native competitor, the northern map turtle (Graptemys geographica). The population of T. s. elegans remained small for approximately 2.5 decades, then significantly increased in conjunction with habitat degradation in the form of increased silt/sediment deposits and nuisance aquatic vegetation growth. Our results demonstrate how a generalist species can expand and establish a population in an area impacted by multiple anthropogenic stressors. This research reveals how ecological communities become characterized by more generalist species following anthropogenically-induced competitive release caused by harvesting of native competitors, habitat degradation, and extreme flooding associated with land cover and climate change.
与人类活动相结合，生态群落正变得越来越以多面手物种为典型。使用长期数据集(1968-2019)，我们记录了本地通才物种红耳滑鱼(Trachemys scripta elegans)在河流群落中的扩张，并研究了随后与生态系统内短期和长期变化一起发生的种群变化。由于当地竞争对手北地龟(Graptemys geographis)的数量因采收而减少，因此，北地龟得以扩展到一个新的地理区域。秀丽隐杆线虫的种群数量在大约25年的时间里保持在较小的水平，然后随着栖息地的退化而显著增加，表现为泥沙淤积的增加和有害的水生植被的生长。我们的研究结果表明，一个通才物种如何在一个受到多种人为压力因素影响的地区扩大和建立种群。本研究揭示了生态群落是如何在本地竞争者的收获、栖息地退化以及与土地覆盖和气候变化相关的极端洪水引起的人为诱导竞争释放后，以更多的多面手物种为特征的。
{"title":"Factors contributing to the range expansion and population increase of a native generalist species","authors":"Eleanor G. Tate, Amber L. Pitt, Myles D. Little, Joseph J. Tavano, M. Nickerson","doi":"10.1163/15685381-bja10098","DOIUrl":"https://doi.org/10.1163/15685381-bja10098","url":null,"abstract":"\u0000Ecological communities are becoming more typified by generalist species in conjunction with anthropogenic activities. Using a long-term dataset (1968-2019), we documented the expansion of a native generalist species, the red-eared slider (Trachemys scripta elegans), into a river community, and studied the subsequent population changes that occurred in conjunction with short- and long-term changes within the ecosystem. Trachemys scripta elegans was able to expand into a new geographic area following a harvesting-induced population decline of a native competitor, the northern map turtle (Graptemys geographica). The population of T. s. elegans remained small for approximately 2.5 decades, then significantly increased in conjunction with habitat degradation in the form of increased silt/sediment deposits and nuisance aquatic vegetation growth. Our results demonstrate how a generalist species can expand and establish a population in an area impacted by multiple anthropogenic stressors. This research reveals how ecological communities become characterized by more generalist species following anthropogenically-induced competitive release caused by harvesting of native competitors, habitat degradation, and extreme flooding associated with land cover and climate change.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47950444","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 : 2022-06-29DOI: 10.1163/15685381-bja10096
F. Arfuso, R. D. Cerutti, M. C. Scaglione, A. Sciabarrasi, C. Giannetto, G. Piccione
Turtles as many other reptiles are capable of orientating their bodies toward the sun. This conduct requires the presence of an internal biological chronometer in the organism that regulates this behavior. Thus, a description of the internal clock in these reptiles is of interest. The assessment of locomotor activity can be considered a reliable indicator of biological clock function. This study aimed to investigate the effect of different artificial photoperiod and ambient temperature schedules on total locomotor activity of female Chelonoidis chilensis and its rhythmicity. Six C. chilensis specimens were exposed to different artificial photoperiods and temperature regimes each fixed for seven days. It was observed that the activity period during the different experimental schedules was close to the 24 hours indicating a daily rhythmicity. Moreover, all tortoises showed a similar total locomotor activity pattern displaying the most of motion during light phase. Under the condition of constant light tortoises exhibited a self-sustaining rhythm not entrained to light and temperature zeitgebers, thus, suggesting its possible endogenous periodicity. Though this study deepens the knowledge on the rhythmic system of C. chilensis, further investigations are needed to achieve a more detailed understanding of tortoise biological clock.
{"title":"Evaluation of locomotor activity in female Chelonoidis chilensis (Testudinidae, Gray 1870) in response to artificial photoperiod and temperature treatments","authors":"F. Arfuso, R. D. Cerutti, M. C. Scaglione, A. Sciabarrasi, C. Giannetto, G. Piccione","doi":"10.1163/15685381-bja10096","DOIUrl":"https://doi.org/10.1163/15685381-bja10096","url":null,"abstract":"\u0000Turtles as many other reptiles are capable of orientating their bodies toward the sun. This conduct requires the presence of an internal biological chronometer in the organism that regulates this behavior. Thus, a description of the internal clock in these reptiles is of interest. The assessment of locomotor activity can be considered a reliable indicator of biological clock function. This study aimed to investigate the effect of different artificial photoperiod and ambient temperature schedules on total locomotor activity of female Chelonoidis chilensis and its rhythmicity. Six C. chilensis specimens were exposed to different artificial photoperiods and temperature regimes each fixed for seven days. It was observed that the activity period during the different experimental schedules was close to the 24 hours indicating a daily rhythmicity. Moreover, all tortoises showed a similar total locomotor activity pattern displaying the most of motion during light phase. Under the condition of constant light tortoises exhibited a self-sustaining rhythm not entrained to light and temperature zeitgebers, thus, suggesting its possible endogenous periodicity. Though this study deepens the knowledge on the rhythmic system of C. chilensis, further investigations are needed to achieve a more detailed understanding of tortoise biological clock.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43099513","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 : 2022-06-28DOI: 10.1163/15685381-bja10094
M. Paracuellos, E. Rodríguez‐Caballero, Enrique Villanueva, Mauricio Santa, Fernando Alcalde, Miguel A. Dionisio, J. R. Fernández Cardenete, M. P. García, Julio Hernández, M. Tapia, S. Yubero, Arturo Cuines, J. Larios, Antonio Lorenzo, I. Pozo, J. Avilés
Population monitoring is essential to determine different aspects of the ecology and conservation of the species. In anurans, recording the acoustic activity of choruses allows surveying populations. Therefore, knowing the timing of male calls is fundamental to achieve this goal. Here we monitored calling activity of the Mediterranean tree frog (Hyla meridionalis) at eight localities in southern Iberian Peninsula and western North Africa in the frame of a citizen science program. Subsequently, after summarizing call activity with Non-metric Multidimensional Scaling, we aimed to identify the geographic and environmental variables that associate with the calling activity of frogs. The results of the 258-hour census showed that male tree frogs called mainly from December to July, although the duration and intensity of choruses varied, depending on the elevation and seasonality of the water bodies. Males sang earlier and had more durable call activities at lower elevation sites, which are sites with higher and more stable ambient temperatures. Also, calling activity was lower in sites where water fluctuates more over the annual cycle. Our results provide a first overview of the calling activity of the Mediterranean tree frog over a relatively large set of populations encompassing a wide variety of environmental conditions in its westernmost range of distribution. However, further studies relying on more intensive sampling, likely using automatic recorders, would be desirable to achieve a full understanding of the calling activity of tree frogs in the region.
{"title":"Citizen science reveals broad-scale variation of calling activity of the Mediterranean tree frog (Hyla meridionalis) in its westernmost range","authors":"M. Paracuellos, E. Rodríguez‐Caballero, Enrique Villanueva, Mauricio Santa, Fernando Alcalde, Miguel A. Dionisio, J. R. Fernández Cardenete, M. P. García, Julio Hernández, M. Tapia, S. Yubero, Arturo Cuines, J. Larios, Antonio Lorenzo, I. Pozo, J. Avilés","doi":"10.1163/15685381-bja10094","DOIUrl":"https://doi.org/10.1163/15685381-bja10094","url":null,"abstract":"\u0000Population monitoring is essential to determine different aspects of the ecology and conservation of the species. In anurans, recording the acoustic activity of choruses allows surveying populations. Therefore, knowing the timing of male calls is fundamental to achieve this goal. Here we monitored calling activity of the Mediterranean tree frog (Hyla meridionalis) at eight localities in southern Iberian Peninsula and western North Africa in the frame of a citizen science program. Subsequently, after summarizing call activity with Non-metric Multidimensional Scaling, we aimed to identify the geographic and environmental variables that associate with the calling activity of frogs. The results of the 258-hour census showed that male tree frogs called mainly from December to July, although the duration and intensity of choruses varied, depending on the elevation and seasonality of the water bodies. Males sang earlier and had more durable call activities at lower elevation sites, which are sites with higher and more stable ambient temperatures. Also, calling activity was lower in sites where water fluctuates more over the annual cycle. Our results provide a first overview of the calling activity of the Mediterranean tree frog over a relatively large set of populations encompassing a wide variety of environmental conditions in its westernmost range of distribution. However, further studies relying on more intensive sampling, likely using automatic recorders, would be desirable to achieve a full understanding of the calling activity of tree frogs in the region.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43789679","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 : 2022-06-28DOI: 10.1163/15685381-bja10095
J. Renet, Théo Dokhelar, Félix Thirion, L. Tatin, C. Pernollet, Laure Bourgault
The knowledge of a species’ spatial ecology is essential for its conservation as it helps to implement targeted protection measures to suitable habitats. In 2011 and 2013, two French populations of ocellated lizards Timon lepidus were monitored through very high frequency (VHF) radio telemetry in two distinct Mediterranean habitats: a 77 ha scrubland (n = 8) and a 1590 ha semi-arid steppe (n = 11) corresponding to a heterogeneous and homogeneous habitat respectively. The variability in spatial estimates for the seasonal habitat use of the ocellated lizard was compared within the two sites using the Autocorrelated Kernel Density Estimation (AKDE). Recursive movement patterns and spatial repartition of shelters were further assessed to study the habitat influence on the species’ space use. No significant differences between sexes or sites were identified in the computed AKDE ranges. This inter-site approach demonstrated higher shelter revisits in core-areas than in the rest of estimated home ranges for both sites. A higher shelter density was observed in the core areas of the lizards than in the rest of their home-ranges for the Mediterranean scrubland but not for the semi-arid steppe. Such findings might attest to the species’ adaptive capabilities within two distinct Mediterranean ecosystems.
{"title":"Spatial pattern and shelter distribution of the ocellated lizard (Timon lepidus) in two distinct Mediterranean habitats","authors":"J. Renet, Théo Dokhelar, Félix Thirion, L. Tatin, C. Pernollet, Laure Bourgault","doi":"10.1163/15685381-bja10095","DOIUrl":"https://doi.org/10.1163/15685381-bja10095","url":null,"abstract":"\u0000The knowledge of a species’ spatial ecology is essential for its conservation as it helps to implement targeted protection measures to suitable habitats. In 2011 and 2013, two French populations of ocellated lizards Timon lepidus were monitored through very high frequency (VHF) radio telemetry in two distinct Mediterranean habitats: a 77 ha scrubland (n = 8) and a 1590 ha semi-arid steppe (n = 11) corresponding to a heterogeneous and homogeneous habitat respectively. The variability in spatial estimates for the seasonal habitat use of the ocellated lizard was compared within the two sites using the Autocorrelated Kernel Density Estimation (AKDE). Recursive movement patterns and spatial repartition of shelters were further assessed to study the habitat influence on the species’ space use. No significant differences between sexes or sites were identified in the computed AKDE ranges. This inter-site approach demonstrated higher shelter revisits in core-areas than in the rest of estimated home ranges for both sites. A higher shelter density was observed in the core areas of the lizards than in the rest of their home-ranges for the Mediterranean scrubland but not for the semi-arid steppe. Such findings might attest to the species’ adaptive capabilities within two distinct Mediterranean ecosystems.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43845379","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 : 2022-06-02DOI: 10.1163/15685381-bja10093
I. Espasandín, P. Galán, F. Martínez‐Freiría
Numerous dietary studies have shown that European vipers (genus Vipera) present low feeding frequency and a specialist diet, which is characterised by a marked ontogenetic shift. However, how eco-geographic factors shape species’ feeding ecology remains scarcely addressed. We investigated the feeding ecology of the Iberian adder, Vipera seoanei, examining 402 specimens distributed across its distributional range and addressing how biological, temporal and eco-geographic factors relate to the species feeding activity and dietary consumption. Our results indicated a low feeding frequency in the species, higher in juveniles than in adults. Adult females showed higher rates of prey consumption than adult males, which match to the distinct reproductive demands of both sexes, although no differences between reproductive and non-reproductive females were found. V. seoanei preyed on a varied taxa spectrum, but showed a rather specialist diet based on small mammals. Amphibians and reptiles were also an important part of its diet, particularly in the juveniles. Body size was found as the single biological trait related to the consumption of major prey groups, supporting the occurrence of an ontogenetic shift in the diet. Two habitat and two climatic factors correlated to the consumption of major prey groups, reflecting the ecological requirements of prey across the viper’s range. Overall, this study extends the existing knowledge on the feeding ecology of European vipers, signalling how energy intake and allometric constraints shape the feeding activity and dietary consumption of the species across the geography, leading to distinct feeding strategies in juveniles and adults.
{"title":"Sex, size and eco-geographic factors affect the feeding ecology of the Iberian adder, Vipera seoanei","authors":"I. Espasandín, P. Galán, F. Martínez‐Freiría","doi":"10.1163/15685381-bja10093","DOIUrl":"https://doi.org/10.1163/15685381-bja10093","url":null,"abstract":"\u0000Numerous dietary studies have shown that European vipers (genus Vipera) present low feeding frequency and a specialist diet, which is characterised by a marked ontogenetic shift. However, how eco-geographic factors shape species’ feeding ecology remains scarcely addressed. We investigated the feeding ecology of the Iberian adder, Vipera seoanei, examining 402 specimens distributed across its distributional range and addressing how biological, temporal and eco-geographic factors relate to the species feeding activity and dietary consumption. Our results indicated a low feeding frequency in the species, higher in juveniles than in adults. Adult females showed higher rates of prey consumption than adult males, which match to the distinct reproductive demands of both sexes, although no differences between reproductive and non-reproductive females were found. V. seoanei preyed on a varied taxa spectrum, but showed a rather specialist diet based on small mammals. Amphibians and reptiles were also an important part of its diet, particularly in the juveniles. Body size was found as the single biological trait related to the consumption of major prey groups, supporting the occurrence of an ontogenetic shift in the diet. Two habitat and two climatic factors correlated to the consumption of major prey groups, reflecting the ecological requirements of prey across the viper’s range. Overall, this study extends the existing knowledge on the feeding ecology of European vipers, signalling how energy intake and allometric constraints shape the feeding activity and dietary consumption of the species across the geography, leading to distinct feeding strategies in juveniles and adults.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47101925","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 : 2022-05-13DOI: 10.1163/15685381-bja10092
L. Luiselli, B. Stille, M. Stille, W. Buttemer, T. Madsen
We analysed the effects of body mass on the monthly activity patterns of six Mediterranean lacertid lizard taxa, four relatively small species, the Italian wall lizard (Podarcis siculus), the common wall lizard (Podarcis muralis), the blue-throated keeled lizard (Algyroides nigropunctatus), and the Ionian wall lizard (Podarcis ionicus), and two larger species, the western green lizard (Lacerta bilineata) and the Balkan green lizard (Lacerta trilineata). The highest number of observations for all six species occurred in April and May and the lowest in July and August, the latter being the hottest and driest months of the year. The two larger species were mainly active from March to July, whereas the four smaller species had an additional period of high activity from September to November. As all six species reproduce during spring, the increase in activity of the smaller species in autumn was consequently unrelated to reproductive behaviour. There was no difference in seasonal activity of the two smaller Italian species at sites with or without the larger green lizards. It is therefore unlikely that interference competition/predation by green lizards caused the increased autumnal activity of the smaller lizards. We suggest that due to their lower mass-specific metabolic rates, larger species can obtain sufficient lipid stores over a shorter annual activity to ensure successful reproduction the subsequent spring. By contrast, smaller species have greater need to replenish their lipid reserves after summer fasting and therefore resume much higher activity levels in September to November to attain this goal.
{"title":"Mass-related differences in metabolic rate and fasting endurance explain divergence in seasonal activity of Mediterranean lizards","authors":"L. Luiselli, B. Stille, M. Stille, W. Buttemer, T. Madsen","doi":"10.1163/15685381-bja10092","DOIUrl":"https://doi.org/10.1163/15685381-bja10092","url":null,"abstract":"\u0000We analysed the effects of body mass on the monthly activity patterns of six Mediterranean lacertid lizard taxa, four relatively small species, the Italian wall lizard (Podarcis siculus), the common wall lizard (Podarcis muralis), the blue-throated keeled lizard (Algyroides nigropunctatus), and the Ionian wall lizard (Podarcis ionicus), and two larger species, the western green lizard (Lacerta bilineata) and the Balkan green lizard (Lacerta trilineata). The highest number of observations for all six species occurred in April and May and the lowest in July and August, the latter being the hottest and driest months of the year. The two larger species were mainly active from March to July, whereas the four smaller species had an additional period of high activity from September to November. As all six species reproduce during spring, the increase in activity of the smaller species in autumn was consequently unrelated to reproductive behaviour. There was no difference in seasonal activity of the two smaller Italian species at sites with or without the larger green lizards. It is therefore unlikely that interference competition/predation by green lizards caused the increased autumnal activity of the smaller lizards. We suggest that due to their lower mass-specific metabolic rates, larger species can obtain sufficient lipid stores over a shorter annual activity to ensure successful reproduction the subsequent spring. By contrast, smaller species have greater need to replenish their lipid reserves after summer fasting and therefore resume much higher activity levels in September to November to attain this goal.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47294730","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 : 2022-05-11DOI: 10.1163/15685381-bja10089
Mona van Schingen-Khan, L. M. F. Barthel, D. Pham, C. Pham, T. Nguyen, T. Ziegler, M. Bonkowski
Climate change is considered to negatively affect vertebrate biodiversity. Lizards in tropical regions are considered particularly vulnerable due to their narrow temperature tolerances. The crocodile lizard Shinisaurus crocodilurus, an ecologically specialized semiaquatic species, is under the risk of extinction due to habitat loss and overharvesting. It is only found in isolated relict populations in southern China and northern Vietnam. Data on the thermal niche of the species are crucial to assess its vulnerability to climatic changes. We developed a backpack system with temperature data loggers for S. crocodilurus in order to monitor the lizard’s temperature preferences in its natural habitat in Vietnam. We found that S. crocodilurus vietnamensis preferred a mean ambient temperature range of 24 ± 1°C (min-max: 22-31°C) at natural habitat sites, a far lower temperature amplitude compared to the recorded ambient temperature range at habitat sites. In its natural habitat, S. crocodilurus vietnamensis avoided in particular high temperatures, indicating the importance of constantly cool streams and intact vegetation for the provision of shade and shelter. We further provide first insights into the seasonal variation in microhabitat use and activity of S. crocodilurus vietnamensis based on data from individuals kept in outdoor enclosures under natural climatic conditions in Vietnam, collected daily over a period of eight months. Our results aim to aid further conservation measures for the species, such as the identification and protection of core habitat sites and sites for restocking, as well as to adjust and improve conservation breeding programs for the species.
{"title":"Will climatic changes affect the Vietnamese crocodile lizard? Seasonal variation in microclimate and activity pattern of Shinisaurus crocodilurus vietnamensis","authors":"Mona van Schingen-Khan, L. M. F. Barthel, D. Pham, C. Pham, T. Nguyen, T. Ziegler, M. Bonkowski","doi":"10.1163/15685381-bja10089","DOIUrl":"https://doi.org/10.1163/15685381-bja10089","url":null,"abstract":"\u0000Climate change is considered to negatively affect vertebrate biodiversity. Lizards in tropical regions are considered particularly vulnerable due to their narrow temperature tolerances. The crocodile lizard Shinisaurus crocodilurus, an ecologically specialized semiaquatic species, is under the risk of extinction due to habitat loss and overharvesting. It is only found in isolated relict populations in southern China and northern Vietnam. Data on the thermal niche of the species are crucial to assess its vulnerability to climatic changes. We developed a backpack system with temperature data loggers for S. crocodilurus in order to monitor the lizard’s temperature preferences in its natural habitat in Vietnam. We found that S. crocodilurus vietnamensis preferred a mean ambient temperature range of 24 ± 1°C (min-max: 22-31°C) at natural habitat sites, a far lower temperature amplitude compared to the recorded ambient temperature range at habitat sites. In its natural habitat, S. crocodilurus vietnamensis avoided in particular high temperatures, indicating the importance of constantly cool streams and intact vegetation for the provision of shade and shelter. We further provide first insights into the seasonal variation in microhabitat use and activity of S. crocodilurus vietnamensis based on data from individuals kept in outdoor enclosures under natural climatic conditions in Vietnam, collected daily over a period of eight months. Our results aim to aid further conservation measures for the species, such as the identification and protection of core habitat sites and sites for restocking, as well as to adjust and improve conservation breeding programs for the species.","PeriodicalId":50799,"journal":{"name":"Amphibia-Reptilia","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2022-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44530765","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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