Agustin Camacho - Academia.edu (original) (raw)
Papers by Agustin Camacho
Dataset showing interactions of several factors with the critical thermal maximum and voluntary t... more Dataset showing interactions of several factors with the critical thermal maximum and voluntary thermal maximum of leaf cutting ants.
Supplementary material containing the raw data, tables, scripts, and graphs from the study "... more Supplementary material containing the raw data, tables, scripts, and graphs from the study "Leaf-cutting ants' CTmax and VTmax changes with size, heating rates, hydration level, and humidity".
Supplementary material containing the raw data, tables, scripts, and graphs from the study "... more Supplementary material containing the raw data, tables, scripts, and graphs from the study "Leaf-cutting ants' CTmax and VTmax changes with size, heating rates, hydration level, and humidity".
Dataset showing interactions of several factors with the critical thermal maximum and voluntary t... more Dataset showing interactions of several factors with the critical thermal maximum and voluntary thermal maximum of leaf cutting ants.
Dataset showing interactions of several factors with the critical thermal maximum and voluntary t... more Dataset showing interactions of several factors with the critical thermal maximum and voluntary thermal maximum of leaf cutting ants.<br>
datasets and scripts that allow reproducing the article with that name<br>
Datafile_S1: Data matrix for RAxML analysis for single batch RADseq dat
To understand species′ climatic vulnerability, our measures of species’ thermal tolerance should ... more To understand species′ climatic vulnerability, our measures of species’ thermal tolerance should predict their geographic thermal limits. Yet, this assumption is ungranted. We tested if animals′ heat tolerance restrict the warmest temperatures they can live at (Tmax), distinguishing among species differently challenged by their thermal environment. For that, we compiled 2350 measurements of species’ heat tolerance indexes and corresponding Tmax, measured at different microhabitats. We show that reptiles, a flagship for climatic vulnerability studies, are particularly unbounded by their heat tolerance. Contrarily, tolerance restricted marine fish’ geography in a non-linear fashion which contrasts with terrestrial taxa. Behavioral tolerance indexes, widely used to predict vulnerability, predicted Tmax inconsistently across Tmax indexes, or were inversely related to it. Animals’ heat tolerance restricts geographic limits more strongly for more thermally challenged species. In turn, fac...
Critical thermal limits (CTmax and CTmin) are predicted to decrease with elevation, with greater ... more Critical thermal limits (CTmax and CTmin) are predicted to decrease with elevation, with greater change in CTmin, and the risk to suffer heat and cold stress increasing at the gradient ends. A central prediction is that populations will adapt to the prevailing climatic conditions. Yet, reliable support for such expectation is scant because of the complexity of integrating phenotypic and molecular divergence. We propose that phenotypic plasticity and breeding phenology may hinder local adaptation cancelling the appearance of adaptive patterns. We examined intraspecific variation of CTmax/CTmin in 11 populations of an amphibian across an elevational gradient, and assessed (1) the existence of local adaptation through a PST-FST comparison, (2) the acclimation scope in both thermal limits, and (3) the vulnerability to suffer acute heat (CTmax–tmax) and cold (tmin–CTmin) thermal stress, measured at both macro- and microclimatic scales. Our study revealed significant microgeographic varia...
Zootaxa, 2008
A new species of Bachia of the bresslaui group, is described from Estação Ecológica Serra Geral d... more A new species of Bachia of the bresslaui group, is described from Estação Ecológica Serra Geral do Tocantins, a recently created protected area in the Central Brazilian Cerrados of state of Tocantins. The new species is most similar to Bachia psamophila from which it differs in limb morphology and head and body scalation. As in Bachia psamophila the shovelshaped snout of the new species is highly prominent, an adaptation related to its psamophilous habits.
Integrative zoology, Jan 9, 2018
Zoologists rely on mechanistic niche models of behavioral thermoregulation to understand how anim... more Zoologists rely on mechanistic niche models of behavioral thermoregulation to understand how animals respond to climate change. These models predict that species will need to disperse to higher altitudes to persist in a warmer world. However, thermal stress and thus thermoregulatory behavior may depend on atmospheric oxygen as well as environmental temperatures. Severe hypoxia causes animals to prefer lower body temperatures, which could be interpreted as evidence that oxygen supply limits heat tolerance. Such a constraint could prevent animals from successfully dispersing to high elevations during climate change. Still, an effect of oxygen supply on preferred body temperature has only been observed when oxygen concentrations fall far below levels experienced in nature. To see whether animals perceive greater thermal stress at an ecologically relevant level of hypoxia, we studied the thermoregulatory behavior of lizards (Sceloporus tristichus) exposed to oxygen concentrations of 13%...
Biota Neotropica, 2011
Os Cerrados sul-americanos abrigam alta diversidade de répteis, incluindo elevado número de endem... more Os Cerrados sul-americanos abrigam alta diversidade de répteis, incluindo elevado número de endemismos. No entanto, o conhecimento desta diversidade é ainda incompleto frente à acelerada transformação das paisagens naturais no Brasil central. Constituem, portanto, uma das regiões prioritárias para estudo e conservação da biodiversidade mundial. Estudos intensivos sobre a fauna de répteis do Cerrado são necessários e urgentes para melhor compreensão dos processos que levaram à sua origem e distribuição e para subsidiar ações de conservação. Por meio de métodos padronizados, amostramos duas regiões ainda inexploradas da Estação Ecológica Serra Geral do Tocantins, situada na região do Jalapão. Registramos 45 espécies de répteis para a EESGT e entorno, o que representa uma riqueza alta e comparável à de outras regiões bem amostradas do Cerrado. Curvas de acumulação e estimadores indicam que a riqueza local de lagartos e anfisbenídeos aproxima-se da riqueza real enquanto a de serpentes é...
Zootaxa, 2013
More than a century after its discovery by Ernest Garbe, and almost 80 years after its original d... more More than a century after its discovery by Ernest Garbe, and almost 80 years after its original description, we obtained a series of specimens of the earless gymnophthalmid Anotosaura collaris, the type species of the genus, up to now known only by a single specimen. On the basis of the material obtained at and close to the type locality we redescribe the species, adding information about the external and hemipenial morphology, osteology and karytoype. Molecular data confirm its sister relationship with Anotosaura vanzolinia as well as the close relationship of Anotosaura with the Ecpleopodini Colobosauroides and Dryadosaura. We supplement this information with thermophysiological, ecogeographical, karyotypic and ecological data.
Zootaxa, 2013
A new species of Bachia of the bresslaui group, Bachia geralista sp. nov., is described from Plan... more A new species of Bachia of the bresslaui group, Bachia geralista sp. nov., is described from Planalto dos Gerais, an old and partially dissected plateau extending along the Cerrados of Bahia, Minas Gerais and Tocantins states, Brazil. The new species is morphologically similar to B. bresslaui, with which it has been confused; however head scalation resembles other species from sandy spots within the Cerrado (B. psamophila and B. oxyrhina). Like in B. psamophila and B. oxyrhi-na, the shovel-shaped snout of the new species is highly prominent, a typical trait of psammophilous habits in other gym-nophthalmids. The examination of specimens of B. bresslaui from several populations within the Cerrado revealed great variation among localities, leading to the reidentification of a specimen from Utiariti, Mato Grosso, previously referred to in the literature as the second record of B. bresslaui, as the recently described B. didactyla, suggesting that cryptic diversity might remain still undi...
Molecular Phylogenetics and Evolution, 2012
Dendrophryniscus is an early diverging clade of bufonids represented by few small-bodied species ... more Dendrophryniscus is an early diverging clade of bufonids represented by few small-bodied species distributed in Amazonia and the Atlantic Forest. We used mitochondrial (414 bp of 12S, 575 bp of 16S genes) and nuclear DNA (785 bp of RAG-1) to investigate phylogenetic relationships and the timing of diversification within the genus. These molecular data were gathered from 23 specimens from 19 populations, including eight out of the 10 nominal species of the genus as well as Rhinella boulengeri. Analyses also included sequences of representatives of 18 other bufonid genera that were publically available. We also examined morphological characters to analyze differences within Dendrophryniscus. We found deep genetic divergence between an Amazonian and an Atlantic Forest clade, dating back to Eocene. Morphological data corroborate this distinction. We thus propose to assign the Amazonian species to a new genus, Amazonella. The species currently named R. boulengeri, which has been previously assigned to the genus Rhamphophryne, is shown to be closely related to Dendrophryniscus species. Our findings illustrate cryptic trends in bufonid morphological evolution, and point to a deep history of persistence and diversification within the Amazonian and Atlantic rainforests. We discuss our results in light of available paleoecological data and the biogeographic patterns observed in other similarly distributed groups.
Biotropica, 2009
Long-term conservation in biodiversity hotspots depends on the recovery of communities in seconda... more Long-term conservation in biodiversity hotspots depends on the recovery of communities in secondary forest fragments. In most cases, however, recovery strategies for these areas are based only on passive restoration. It is therefore necessary to determine the efficiency of such strategies. In this study, we assess the efficiency of passive restoration on a 567-ha 28-yr-old fragment of Atlantic Rainforest in Northeastern Brazil. We measured richness, composition, abundance and biomass of a lizard taxocene and also vegetation structure and availability of several microhabitat descriptors in 18 plots of this secondary forest. We then compared them with measures in 29 plots from two neighboring reference sites. Species richness, abundance, biomass and microhabitat descriptors availability inside the secondary fragment did not differ from reference sites. However, composition and vegetation structure showed small differences. Some forest specialist lizards, which should be a focus of conservation efforts in fragmented landscapes of the Atlantic Rainforest, were not found in the fragment and data indicate that this was not due to sampling or a lack of suitable habitat or microhabitat. In the presence of preserved source sites, passive restoration may be a cheap and effective way to recover lizard taxocenes of the Atlantic Rainforest. Some of the species may need to be reintroduced to accelerate the full recovery of original composition of lizard taxocenes in secondary Atlantic Rainforests.
Dataset showing interactions of several factors with the critical thermal maximum and voluntary t... more Dataset showing interactions of several factors with the critical thermal maximum and voluntary thermal maximum of leaf cutting ants.
Supplementary material containing the raw data, tables, scripts, and graphs from the study "... more Supplementary material containing the raw data, tables, scripts, and graphs from the study "Leaf-cutting ants' CTmax and VTmax changes with size, heating rates, hydration level, and humidity".
Supplementary material containing the raw data, tables, scripts, and graphs from the study "... more Supplementary material containing the raw data, tables, scripts, and graphs from the study "Leaf-cutting ants' CTmax and VTmax changes with size, heating rates, hydration level, and humidity".
Dataset showing interactions of several factors with the critical thermal maximum and voluntary t... more Dataset showing interactions of several factors with the critical thermal maximum and voluntary thermal maximum of leaf cutting ants.
Dataset showing interactions of several factors with the critical thermal maximum and voluntary t... more Dataset showing interactions of several factors with the critical thermal maximum and voluntary thermal maximum of leaf cutting ants.<br>
datasets and scripts that allow reproducing the article with that name<br>
Datafile_S1: Data matrix for RAxML analysis for single batch RADseq dat
To understand species′ climatic vulnerability, our measures of species’ thermal tolerance should ... more To understand species′ climatic vulnerability, our measures of species’ thermal tolerance should predict their geographic thermal limits. Yet, this assumption is ungranted. We tested if animals′ heat tolerance restrict the warmest temperatures they can live at (Tmax), distinguishing among species differently challenged by their thermal environment. For that, we compiled 2350 measurements of species’ heat tolerance indexes and corresponding Tmax, measured at different microhabitats. We show that reptiles, a flagship for climatic vulnerability studies, are particularly unbounded by their heat tolerance. Contrarily, tolerance restricted marine fish’ geography in a non-linear fashion which contrasts with terrestrial taxa. Behavioral tolerance indexes, widely used to predict vulnerability, predicted Tmax inconsistently across Tmax indexes, or were inversely related to it. Animals’ heat tolerance restricts geographic limits more strongly for more thermally challenged species. In turn, fac...
Critical thermal limits (CTmax and CTmin) are predicted to decrease with elevation, with greater ... more Critical thermal limits (CTmax and CTmin) are predicted to decrease with elevation, with greater change in CTmin, and the risk to suffer heat and cold stress increasing at the gradient ends. A central prediction is that populations will adapt to the prevailing climatic conditions. Yet, reliable support for such expectation is scant because of the complexity of integrating phenotypic and molecular divergence. We propose that phenotypic plasticity and breeding phenology may hinder local adaptation cancelling the appearance of adaptive patterns. We examined intraspecific variation of CTmax/CTmin in 11 populations of an amphibian across an elevational gradient, and assessed (1) the existence of local adaptation through a PST-FST comparison, (2) the acclimation scope in both thermal limits, and (3) the vulnerability to suffer acute heat (CTmax–tmax) and cold (tmin–CTmin) thermal stress, measured at both macro- and microclimatic scales. Our study revealed significant microgeographic varia...
Zootaxa, 2008
A new species of Bachia of the bresslaui group, is described from Estação Ecológica Serra Geral d... more A new species of Bachia of the bresslaui group, is described from Estação Ecológica Serra Geral do Tocantins, a recently created protected area in the Central Brazilian Cerrados of state of Tocantins. The new species is most similar to Bachia psamophila from which it differs in limb morphology and head and body scalation. As in Bachia psamophila the shovelshaped snout of the new species is highly prominent, an adaptation related to its psamophilous habits.
Integrative zoology, Jan 9, 2018
Zoologists rely on mechanistic niche models of behavioral thermoregulation to understand how anim... more Zoologists rely on mechanistic niche models of behavioral thermoregulation to understand how animals respond to climate change. These models predict that species will need to disperse to higher altitudes to persist in a warmer world. However, thermal stress and thus thermoregulatory behavior may depend on atmospheric oxygen as well as environmental temperatures. Severe hypoxia causes animals to prefer lower body temperatures, which could be interpreted as evidence that oxygen supply limits heat tolerance. Such a constraint could prevent animals from successfully dispersing to high elevations during climate change. Still, an effect of oxygen supply on preferred body temperature has only been observed when oxygen concentrations fall far below levels experienced in nature. To see whether animals perceive greater thermal stress at an ecologically relevant level of hypoxia, we studied the thermoregulatory behavior of lizards (Sceloporus tristichus) exposed to oxygen concentrations of 13%...
Biota Neotropica, 2011
Os Cerrados sul-americanos abrigam alta diversidade de répteis, incluindo elevado número de endem... more Os Cerrados sul-americanos abrigam alta diversidade de répteis, incluindo elevado número de endemismos. No entanto, o conhecimento desta diversidade é ainda incompleto frente à acelerada transformação das paisagens naturais no Brasil central. Constituem, portanto, uma das regiões prioritárias para estudo e conservação da biodiversidade mundial. Estudos intensivos sobre a fauna de répteis do Cerrado são necessários e urgentes para melhor compreensão dos processos que levaram à sua origem e distribuição e para subsidiar ações de conservação. Por meio de métodos padronizados, amostramos duas regiões ainda inexploradas da Estação Ecológica Serra Geral do Tocantins, situada na região do Jalapão. Registramos 45 espécies de répteis para a EESGT e entorno, o que representa uma riqueza alta e comparável à de outras regiões bem amostradas do Cerrado. Curvas de acumulação e estimadores indicam que a riqueza local de lagartos e anfisbenídeos aproxima-se da riqueza real enquanto a de serpentes é...
Zootaxa, 2013
More than a century after its discovery by Ernest Garbe, and almost 80 years after its original d... more More than a century after its discovery by Ernest Garbe, and almost 80 years after its original description, we obtained a series of specimens of the earless gymnophthalmid Anotosaura collaris, the type species of the genus, up to now known only by a single specimen. On the basis of the material obtained at and close to the type locality we redescribe the species, adding information about the external and hemipenial morphology, osteology and karytoype. Molecular data confirm its sister relationship with Anotosaura vanzolinia as well as the close relationship of Anotosaura with the Ecpleopodini Colobosauroides and Dryadosaura. We supplement this information with thermophysiological, ecogeographical, karyotypic and ecological data.
Zootaxa, 2013
A new species of Bachia of the bresslaui group, Bachia geralista sp. nov., is described from Plan... more A new species of Bachia of the bresslaui group, Bachia geralista sp. nov., is described from Planalto dos Gerais, an old and partially dissected plateau extending along the Cerrados of Bahia, Minas Gerais and Tocantins states, Brazil. The new species is morphologically similar to B. bresslaui, with which it has been confused; however head scalation resembles other species from sandy spots within the Cerrado (B. psamophila and B. oxyrhina). Like in B. psamophila and B. oxyrhi-na, the shovel-shaped snout of the new species is highly prominent, a typical trait of psammophilous habits in other gym-nophthalmids. The examination of specimens of B. bresslaui from several populations within the Cerrado revealed great variation among localities, leading to the reidentification of a specimen from Utiariti, Mato Grosso, previously referred to in the literature as the second record of B. bresslaui, as the recently described B. didactyla, suggesting that cryptic diversity might remain still undi...
Molecular Phylogenetics and Evolution, 2012
Dendrophryniscus is an early diverging clade of bufonids represented by few small-bodied species ... more Dendrophryniscus is an early diverging clade of bufonids represented by few small-bodied species distributed in Amazonia and the Atlantic Forest. We used mitochondrial (414 bp of 12S, 575 bp of 16S genes) and nuclear DNA (785 bp of RAG-1) to investigate phylogenetic relationships and the timing of diversification within the genus. These molecular data were gathered from 23 specimens from 19 populations, including eight out of the 10 nominal species of the genus as well as Rhinella boulengeri. Analyses also included sequences of representatives of 18 other bufonid genera that were publically available. We also examined morphological characters to analyze differences within Dendrophryniscus. We found deep genetic divergence between an Amazonian and an Atlantic Forest clade, dating back to Eocene. Morphological data corroborate this distinction. We thus propose to assign the Amazonian species to a new genus, Amazonella. The species currently named R. boulengeri, which has been previously assigned to the genus Rhamphophryne, is shown to be closely related to Dendrophryniscus species. Our findings illustrate cryptic trends in bufonid morphological evolution, and point to a deep history of persistence and diversification within the Amazonian and Atlantic rainforests. We discuss our results in light of available paleoecological data and the biogeographic patterns observed in other similarly distributed groups.
Biotropica, 2009
Long-term conservation in biodiversity hotspots depends on the recovery of communities in seconda... more Long-term conservation in biodiversity hotspots depends on the recovery of communities in secondary forest fragments. In most cases, however, recovery strategies for these areas are based only on passive restoration. It is therefore necessary to determine the efficiency of such strategies. In this study, we assess the efficiency of passive restoration on a 567-ha 28-yr-old fragment of Atlantic Rainforest in Northeastern Brazil. We measured richness, composition, abundance and biomass of a lizard taxocene and also vegetation structure and availability of several microhabitat descriptors in 18 plots of this secondary forest. We then compared them with measures in 29 plots from two neighboring reference sites. Species richness, abundance, biomass and microhabitat descriptors availability inside the secondary fragment did not differ from reference sites. However, composition and vegetation structure showed small differences. Some forest specialist lizards, which should be a focus of conservation efforts in fragmented landscapes of the Atlantic Rainforest, were not found in the fragment and data indicate that this was not due to sampling or a lack of suitable habitat or microhabitat. In the presence of preserved source sites, passive restoration may be a cheap and effective way to recover lizard taxocenes of the Atlantic Rainforest. Some of the species may need to be reintroduced to accelerate the full recovery of original composition of lizard taxocenes in secondary Atlantic Rainforests.