Determining the extent of reproductive isolation in cryptic species with dynamic geographic range... more Determining the extent of reproductive isolation in cryptic species with dynamic geographic ranges can yield important insights into the processes that generate and maintain genetic divergence in the absence of severe geographic barriers. We studied mating patterns, propensity to hybridize in nature and subsequent fertilization rates, as well as survival and development of hybrid F1 offspring for three nominal species of the Engystomops petersi species complex in Yasuní National Park, Ecuador. We found at least two species in four out of six locations sampled, and 14.3% of the wild pairs genotyped were mixed-species (heterospecific) crosses. We also found reduced fertilization rates in hybrid crosses between E. petersi females and E. "magnus" males, and between E. "magnus" females and E. "selva" males but not in the reciprocal crosses, suggesting asymmetric reproductive isolation for these species. Larval development times decreased in F1 hybrid crosses...
El objetivo del presente trabajo fue detectar el hábitat mayormente utilizado por la
iguana verde... more El objetivo del presente trabajo fue detectar el hábitat mayormente utilizado por la iguana verde, considerando el efecto de animales callejeros y de la degradación del paisaje, mediante una evaluación rápida en las riberas del Río Milagro del cantón Milagro, en Guayas, Ecuador. Se realizaron muestreos en cinco tramos de las riberas, para poder cuantificar las iguanas, perros y gatos callejeros. Adicionalmente, se cuantificó la disponibilidad de vegetación y se estimó la contaminación observada en varias zonas del Río Milagro. Las observaciones realizadas demuestran que las poblaciones de perros y gatos callejeros no influencian la ocurrencia de iguanas verdes; sin embargo, un numero representativo de iguanas de la localidad tienden a aglomerarse en zonas con menor contaminación y mayor vegetación disponible, áreas que coinciden con los tramos del rio más distantes del centro de la ciudad.
The Ecuadorian coast ecosystems are considered fragile due to anthropic activities, such as lives... more The Ecuadorian coast ecosystems are considered fragile due to anthropic activities, such as livestock production and agriculture, which are important economically. In this study, we document the herpetofauna of Engabao, in Playas Canton, Ecuador, and extend the distribution range of one species of frog. We performed day and night sampling, including transect surveys and visual encounters. Ten species of amphibians and reptiles were recorded. Included among these species the Threatened Ceratophrys stolzmanni (Steindachner, 1882). Engabao is an area intended for livestock production.
To maintain a stable population, an introduced species must be capable of exploiting varied resou... more To maintain a stable population, an introduced species must be capable of exploiting varied resources and adapting to environ- mental conditions different from its native range. The brown anole (Anolis sagrei), one of the most prolific invasive species worldwide, is well established in Ecuador—especially in urban environments throughout Guayaquil and Samborondón (Guayas province). In this research, we describe the feeding habits of male and female brown anoles collected from six different sites: a regenerated wetland ecosystem and five city gardens. We dissected stomach contents in order to record the number and type of prey items, each classified to the lowest identifiable taxonomic category. Our results show that A. sagrei consumes a variety of prey items; Hymenoptera (mainly ants) represented the highest percentage of total gut contents from all sites. In addition, we found that A. sagrei also feeds on insects belonging to the families Cicadidae, Miridae, Scarabeidae, Chrysomelidae and Nitidulidae, all of which are considered to be agricultural pests. As such, we predict that A. sagrei could be an ideal model for biological control studies in urban environments throughout Guayas and perhaps beyond.
We describe two new species of Anolis lizard that are sympatric on
the Amazonian slopes of the An... more We describe two new species of Anolis lizard that are sympatric on the Amazonian slopes of the Andes of southern Ecuador at elevations between 1440 and 1970 m. The new species may be distinguished from other Anolis by external anatomy, mitochondrial divergence and dewlap colour. We estimate the phylogenetic positions of the new species using Bayesian analysis of DNA sequence data including all species of Dactyloa-clade Anolis for which DNA data are available. Anolis hyacintogularis sp. nov. is sister to Anolis calimae, whereas Anolis lososi sp. nov. is sister to Anolis williamsmittermeierorum, herein reported for Ecuador for the first time. Individuals of both new species were collected within a protected area in southern Ecuador, Podocarpus National Park, which suggests that at least some populations of these species are well protected.
The use of sexually selected characters in inter- and intra-sexual
interactions has long been of ... more The use of sexually selected characters in inter- and intra-sexual interactions has long been of interest to evolutionary biologists. Recently, a distinction between sexually selected traits as ornaments versus weapons has been advanced. We investigated the behaviour of an enigmatic lizard with a prominent sexually dimorphic trait in an effort to describe whether the trait was the product of sexual selection and further whether it functioned as a weapon or an ornament. The subject of our study was the Ecuadorian proboscis anole (Anolis proboscis), a slow-moving cryptic species endemic to the north-western slopes of the Andes in Ecuador. Males, but not females, of this species bear a rostral appendage that has been described as an exaggerated trait resulting from sexual selection. However, a thorough description of the use of the rostral appendage in social interactions is lacking. Here, we describe social interactions of this species during 11 male–female courtships and mating interactions, as well as three male–male agonistic interactions. We describe four types of displays by males, many involving the rostral appendage. We found that the rostral appendage is used as an ornament in social displays but not as a weapon in combat. We also show that, unlike other lizards with rostral appendages, male A. proboscis hatch with this structure already developed.
Foam nests have evolved independently in several amphibian groups
as an adaptive response to prev... more Foam nests have evolved independently in several amphibian groups as an adaptive response to prevent predation and desiccation in dry environments. Nests are normally laid on ponds, or in underground galleries, humid forest leaf litter or terrestrial bromeliads. They are built when males or females beat a foam precursor associated with the egg masses extruded by the female. The spawning process requires the synchronic actions of themating pair to obtain a hemispheric nest that protects the offspring. Herein, we describe the spawning behaviour of Engystomops pustulatus based on videos from 13 nesting couples from the lowlands of western Ecuador. Three variables were measured as indicators of male effort: duration ofmixing events, duration of resting periods, and number of kicks per mixing event. We consider that not only male physical effort but also female behaviour influences nest structure. We suggest that nest building requires prolonged and intense physical activity by the male as well as the female’s steady position during spawning and female’s oviposition site selection. Nest building has two phases. In the first phase, the duration of resting periods, the duration of mixing events, and the number of kicks increase and are highly variable. During the second phase the three variables stabilise until the end. The volume of the nest increased mainly during the second phase. In four nesting events we observed kicking movements by the female. To our knowledge, this is the first time that female kicking has been observed in leptodactylid frogs. The function of this behaviour is unknown but our observations suggest that it may be triggered by insufficient male effort. Traditionally, female mate choice in Engystomops has been explained under models of indirect benefits exclusively. We argue that the prolonged male activity during nesting could influence female fitness directly. This will allow the operation of sexual selection via direct benefits.
Determining the extent of reproductive isolation in cryptic species with dynamic geographic range... more Determining the extent of reproductive isolation in cryptic species with dynamic geographic ranges can yield important insights into the processes that generate and maintain genetic divergence in the absence of severe geographic barriers. We studied mating patterns, propensity to hybridize in nature and subsequent fertilization rates, as well as survival and development of hybrid F 1 offspring for three nominal species of the Engystomops petersi species complex in Yasuní National Park, Ecuador. We found at least two species in four out of six locations sampled, and 14.3% of the wild pairs genotyped were mixed-species (heterospeci-fic) crosses. We also found reduced fertilization rates in hybrid crosses between E. petersi females and E. " magnus " males, and between E. " magnus " females and E. " selva " males but not in the reciprocal crosses, suggesting asymmetric reproductive isolation for these species. Larval development times decreased in F 1 hybrid crosses compared to same species (con-specific) crosses, but we did not find significant reduction in larval survival or early meta-morph survival. Our results show evidence of post-mating isolation for at least two hybrid crosses of the cryptic species we studied. The general decrease in fertilization rates in het-erospecific crosses suggests that sexual selection and reinforcement might have not only contributed to the pattern of call variation and behavioral isolation we see between species today, but they may also contribute to further signal divergence and behavioral evolution, especially in locations where hybridization is common and fertilization success is diminished.
We describe the diet of adult and juvenile Engystomops pustulatus from three populations in the E... more We describe the diet of adult and juvenile Engystomops pustulatus from three populations in the Ecuadorian Chocó. Analysis of the items recovered from the gastrointestinal tracts of 95 individuals showed that E. pustulatus has a diverse diet. We identified 52 prey types among 1211 items. The numeric niche breadth, as measured by the Simpson's Index, was 5.37 while the volumetric niche breadth was 5.48. Among juveniles at Cerro Blanco we found a high proportion of small prey items, including termites and ants. Larger items, including snails, coleopterans, and isopods, were most frequent in adults at Patricia Pilar and La Maná. We hypothesize that dietary niche breadth is correlated with the presence of teeth in Engystomops. Engystomops pustulatus has teeth and has a more generalist diet than the termite and ant specialist species E. pustulosus, E. petersi, and E. freibergi, which lack teeth.
We report the first record of the invasive Brown Anole, Anolis sagrei Duméril & Bibron, 1837, in ... more We report the first record of the invasive Brown Anole, Anolis sagrei Duméril & Bibron, 1837, in South America based on nine specimens from Samborondón, Guayas province, Ecuador. We also present some information related to the current distribution in Ecuador, and its possible impacts on native lizard species.
The study of reproductive strategies is central to understand the demography of populations and t... more The study of reproductive strategies is central to understand the demography of populations and the energetic relationships of the species with their ecosystem. Documenting the reproductive natural history of the species is pressing in groups, like amphibians, that are threatened with extinction at a global scale. Herein, we describe the reproductive ecology and spawning behavior of the leptodactylid frog Engystomops pustulatus. In addition, we report observations that suggest the existence of an alternative mating strategy. Our results show that reproduction in E. pustulatus is characterized by high maternal investment (15% egg mass relative to body mass). We found evidence of size-assortative mating with a tendency of larger females to mate with larger males. Clutch size was correlated with female weight, female condition and male size. Larger females showed a tendency to lay larger foam nests and larger nests contained more eggs. At reproductive choruses, there was a male-biased operational sex ratio, indicative of high variance in male reproductive success. We observed an amplectant couple spawning while an additional male was embedded in the foam. We hypothesize that this behavior is evidence of an alternative mating strategy where a small non-amplectant male attempts to fertilize the eggs that are extruded by the amplectant female.
Determining the extent of reproductive isolation in cryptic species with dynamic geographic range... more Determining the extent of reproductive isolation in cryptic species with dynamic geographic ranges can yield important insights into the processes that generate and maintain genetic divergence in the absence of severe geographic barriers. We studied mating patterns, propensity to hybridize in nature and subsequent fertilization rates, as well as survival and development of hybrid F1 offspring for three nominal species of the Engystomops petersi species complex in Yasuní National Park, Ecuador. We found at least two species in four out of six locations sampled, and 14.3% of the wild pairs genotyped were mixed-species (heterospecific) crosses. We also found reduced fertilization rates in hybrid crosses between E. petersi females and E. "magnus" males, and between E. "magnus" females and E. "selva" males but not in the reciprocal crosses, suggesting asymmetric reproductive isolation for these species. Larval development times decreased in F1 hybrid crosses...
El objetivo del presente trabajo fue detectar el hábitat mayormente utilizado por la
iguana verde... more El objetivo del presente trabajo fue detectar el hábitat mayormente utilizado por la iguana verde, considerando el efecto de animales callejeros y de la degradación del paisaje, mediante una evaluación rápida en las riberas del Río Milagro del cantón Milagro, en Guayas, Ecuador. Se realizaron muestreos en cinco tramos de las riberas, para poder cuantificar las iguanas, perros y gatos callejeros. Adicionalmente, se cuantificó la disponibilidad de vegetación y se estimó la contaminación observada en varias zonas del Río Milagro. Las observaciones realizadas demuestran que las poblaciones de perros y gatos callejeros no influencian la ocurrencia de iguanas verdes; sin embargo, un numero representativo de iguanas de la localidad tienden a aglomerarse en zonas con menor contaminación y mayor vegetación disponible, áreas que coinciden con los tramos del rio más distantes del centro de la ciudad.
The Ecuadorian coast ecosystems are considered fragile due to anthropic activities, such as lives... more The Ecuadorian coast ecosystems are considered fragile due to anthropic activities, such as livestock production and agriculture, which are important economically. In this study, we document the herpetofauna of Engabao, in Playas Canton, Ecuador, and extend the distribution range of one species of frog. We performed day and night sampling, including transect surveys and visual encounters. Ten species of amphibians and reptiles were recorded. Included among these species the Threatened Ceratophrys stolzmanni (Steindachner, 1882). Engabao is an area intended for livestock production.
To maintain a stable population, an introduced species must be capable of exploiting varied resou... more To maintain a stable population, an introduced species must be capable of exploiting varied resources and adapting to environ- mental conditions different from its native range. The brown anole (Anolis sagrei), one of the most prolific invasive species worldwide, is well established in Ecuador—especially in urban environments throughout Guayaquil and Samborondón (Guayas province). In this research, we describe the feeding habits of male and female brown anoles collected from six different sites: a regenerated wetland ecosystem and five city gardens. We dissected stomach contents in order to record the number and type of prey items, each classified to the lowest identifiable taxonomic category. Our results show that A. sagrei consumes a variety of prey items; Hymenoptera (mainly ants) represented the highest percentage of total gut contents from all sites. In addition, we found that A. sagrei also feeds on insects belonging to the families Cicadidae, Miridae, Scarabeidae, Chrysomelidae and Nitidulidae, all of which are considered to be agricultural pests. As such, we predict that A. sagrei could be an ideal model for biological control studies in urban environments throughout Guayas and perhaps beyond.
We describe two new species of Anolis lizard that are sympatric on
the Amazonian slopes of the An... more We describe two new species of Anolis lizard that are sympatric on the Amazonian slopes of the Andes of southern Ecuador at elevations between 1440 and 1970 m. The new species may be distinguished from other Anolis by external anatomy, mitochondrial divergence and dewlap colour. We estimate the phylogenetic positions of the new species using Bayesian analysis of DNA sequence data including all species of Dactyloa-clade Anolis for which DNA data are available. Anolis hyacintogularis sp. nov. is sister to Anolis calimae, whereas Anolis lososi sp. nov. is sister to Anolis williamsmittermeierorum, herein reported for Ecuador for the first time. Individuals of both new species were collected within a protected area in southern Ecuador, Podocarpus National Park, which suggests that at least some populations of these species are well protected.
The use of sexually selected characters in inter- and intra-sexual
interactions has long been of ... more The use of sexually selected characters in inter- and intra-sexual interactions has long been of interest to evolutionary biologists. Recently, a distinction between sexually selected traits as ornaments versus weapons has been advanced. We investigated the behaviour of an enigmatic lizard with a prominent sexually dimorphic trait in an effort to describe whether the trait was the product of sexual selection and further whether it functioned as a weapon or an ornament. The subject of our study was the Ecuadorian proboscis anole (Anolis proboscis), a slow-moving cryptic species endemic to the north-western slopes of the Andes in Ecuador. Males, but not females, of this species bear a rostral appendage that has been described as an exaggerated trait resulting from sexual selection. However, a thorough description of the use of the rostral appendage in social interactions is lacking. Here, we describe social interactions of this species during 11 male–female courtships and mating interactions, as well as three male–male agonistic interactions. We describe four types of displays by males, many involving the rostral appendage. We found that the rostral appendage is used as an ornament in social displays but not as a weapon in combat. We also show that, unlike other lizards with rostral appendages, male A. proboscis hatch with this structure already developed.
Foam nests have evolved independently in several amphibian groups
as an adaptive response to prev... more Foam nests have evolved independently in several amphibian groups as an adaptive response to prevent predation and desiccation in dry environments. Nests are normally laid on ponds, or in underground galleries, humid forest leaf litter or terrestrial bromeliads. They are built when males or females beat a foam precursor associated with the egg masses extruded by the female. The spawning process requires the synchronic actions of themating pair to obtain a hemispheric nest that protects the offspring. Herein, we describe the spawning behaviour of Engystomops pustulatus based on videos from 13 nesting couples from the lowlands of western Ecuador. Three variables were measured as indicators of male effort: duration ofmixing events, duration of resting periods, and number of kicks per mixing event. We consider that not only male physical effort but also female behaviour influences nest structure. We suggest that nest building requires prolonged and intense physical activity by the male as well as the female’s steady position during spawning and female’s oviposition site selection. Nest building has two phases. In the first phase, the duration of resting periods, the duration of mixing events, and the number of kicks increase and are highly variable. During the second phase the three variables stabilise until the end. The volume of the nest increased mainly during the second phase. In four nesting events we observed kicking movements by the female. To our knowledge, this is the first time that female kicking has been observed in leptodactylid frogs. The function of this behaviour is unknown but our observations suggest that it may be triggered by insufficient male effort. Traditionally, female mate choice in Engystomops has been explained under models of indirect benefits exclusively. We argue that the prolonged male activity during nesting could influence female fitness directly. This will allow the operation of sexual selection via direct benefits.
Determining the extent of reproductive isolation in cryptic species with dynamic geographic range... more Determining the extent of reproductive isolation in cryptic species with dynamic geographic ranges can yield important insights into the processes that generate and maintain genetic divergence in the absence of severe geographic barriers. We studied mating patterns, propensity to hybridize in nature and subsequent fertilization rates, as well as survival and development of hybrid F 1 offspring for three nominal species of the Engystomops petersi species complex in Yasuní National Park, Ecuador. We found at least two species in four out of six locations sampled, and 14.3% of the wild pairs genotyped were mixed-species (heterospeci-fic) crosses. We also found reduced fertilization rates in hybrid crosses between E. petersi females and E. " magnus " males, and between E. " magnus " females and E. " selva " males but not in the reciprocal crosses, suggesting asymmetric reproductive isolation for these species. Larval development times decreased in F 1 hybrid crosses compared to same species (con-specific) crosses, but we did not find significant reduction in larval survival or early meta-morph survival. Our results show evidence of post-mating isolation for at least two hybrid crosses of the cryptic species we studied. The general decrease in fertilization rates in het-erospecific crosses suggests that sexual selection and reinforcement might have not only contributed to the pattern of call variation and behavioral isolation we see between species today, but they may also contribute to further signal divergence and behavioral evolution, especially in locations where hybridization is common and fertilization success is diminished.
We describe the diet of adult and juvenile Engystomops pustulatus from three populations in the E... more We describe the diet of adult and juvenile Engystomops pustulatus from three populations in the Ecuadorian Chocó. Analysis of the items recovered from the gastrointestinal tracts of 95 individuals showed that E. pustulatus has a diverse diet. We identified 52 prey types among 1211 items. The numeric niche breadth, as measured by the Simpson's Index, was 5.37 while the volumetric niche breadth was 5.48. Among juveniles at Cerro Blanco we found a high proportion of small prey items, including termites and ants. Larger items, including snails, coleopterans, and isopods, were most frequent in adults at Patricia Pilar and La Maná. We hypothesize that dietary niche breadth is correlated with the presence of teeth in Engystomops. Engystomops pustulatus has teeth and has a more generalist diet than the termite and ant specialist species E. pustulosus, E. petersi, and E. freibergi, which lack teeth.
We report the first record of the invasive Brown Anole, Anolis sagrei Duméril & Bibron, 1837, in ... more We report the first record of the invasive Brown Anole, Anolis sagrei Duméril & Bibron, 1837, in South America based on nine specimens from Samborondón, Guayas province, Ecuador. We also present some information related to the current distribution in Ecuador, and its possible impacts on native lizard species.
The study of reproductive strategies is central to understand the demography of populations and t... more The study of reproductive strategies is central to understand the demography of populations and the energetic relationships of the species with their ecosystem. Documenting the reproductive natural history of the species is pressing in groups, like amphibians, that are threatened with extinction at a global scale. Herein, we describe the reproductive ecology and spawning behavior of the leptodactylid frog Engystomops pustulatus. In addition, we report observations that suggest the existence of an alternative mating strategy. Our results show that reproduction in E. pustulatus is characterized by high maternal investment (15% egg mass relative to body mass). We found evidence of size-assortative mating with a tendency of larger females to mate with larger males. Clutch size was correlated with female weight, female condition and male size. Larger females showed a tendency to lay larger foam nests and larger nests contained more eggs. At reproductive choruses, there was a male-biased operational sex ratio, indicative of high variance in male reproductive success. We observed an amplectant couple spawning while an additional male was embedded in the foam. We hypothesize that this behavior is evidence of an alternative mating strategy where a small non-amplectant male attempts to fertilize the eggs that are extruded by the amplectant female.
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Papers by Andrea Narvaez
iguana verde, considerando el efecto de animales callejeros y de la degradación del
paisaje, mediante una evaluación rápida en las riberas del Río Milagro del cantón
Milagro, en Guayas, Ecuador. Se realizaron muestreos en cinco tramos de las riberas,
para poder cuantificar las iguanas, perros y gatos callejeros. Adicionalmente, se
cuantificó la disponibilidad de vegetación y se estimó la contaminación observada
en varias zonas del Río Milagro. Las observaciones realizadas demuestran que las
poblaciones de perros y gatos callejeros no influencian la ocurrencia de iguanas
verdes; sin embargo, un numero representativo de iguanas de la localidad tienden
a aglomerarse en zonas con menor contaminación y mayor vegetación disponible,
áreas que coinciden con los tramos del rio más distantes del centro de la ciudad.
the Amazonian slopes of the Andes of southern Ecuador at elevations
between 1440 and 1970 m. The new species may be distinguished
from other Anolis by external anatomy, mitochondrial divergence
and dewlap colour. We estimate the phylogenetic positions of the
new species using Bayesian analysis of DNA sequence data including
all species of Dactyloa-clade Anolis for which DNA data are available.
Anolis hyacintogularis sp. nov. is sister to Anolis calimae, whereas
Anolis lososi sp. nov. is sister to Anolis williamsmittermeierorum, herein
reported for Ecuador for the first time. Individuals of both new
species were collected within a protected area in southern Ecuador,
Podocarpus National Park, which suggests that at least some populations of these species are well protected.
interactions has long been of interest to evolutionary biologists.
Recently, a distinction between sexually selected traits as ornaments
versus weapons has been advanced. We investigated the behaviour
of an enigmatic lizard with a prominent sexually dimorphic trait in an
effort to describe whether the trait was the product of sexual selection
and further whether it functioned as a weapon or an ornament.
The subject of our study was the Ecuadorian proboscis anole (Anolis
proboscis), a slow-moving cryptic species endemic to the north-western
slopes of the Andes in Ecuador. Males, but not females, of this
species bear a rostral appendage that has been described as an
exaggerated trait resulting from sexual selection. However, a thorough
description of the use of the rostral appendage in social interactions
is lacking. Here, we describe social interactions of this species
during 11 male–female courtships and mating interactions, as well as
three male–male agonistic interactions. We describe four types of
displays by males, many involving the rostral appendage. We found
that the rostral appendage is used as an ornament in social displays
but not as a weapon in combat. We also show that, unlike other
lizards with rostral appendages, male A. proboscis hatch with this
structure already developed.
as an adaptive response to prevent predation and desiccation in dry
environments. Nests are normally laid on ponds, or in underground
galleries, humid forest leaf litter or terrestrial bromeliads. They are built
when males or females beat a foam precursor associated with the egg
masses extruded by the female. The spawning process requires the
synchronic actions of themating pair to obtain a hemispheric nest that
protects the offspring. Herein, we describe the spawning behaviour of
Engystomops pustulatus based on videos from 13 nesting couples from
the lowlands of western Ecuador. Three variables were measured as
indicators of male effort: duration ofmixing events, duration of resting
periods, and number of kicks per mixing event. We consider that not
only male physical effort but also female behaviour influences nest
structure. We suggest that nest building requires prolonged and
intense physical activity by the male as well as the female’s steady
position during spawning and female’s oviposition site selection. Nest
building has two phases. In the first phase, the duration of resting
periods, the duration of mixing events, and the number of kicks
increase and are highly variable. During the second phase the three
variables stabilise until the end. The volume of the nest increased
mainly during the second phase. In four nesting events we observed
kicking movements by the female. To our knowledge, this is the first
time that female kicking has been observed in leptodactylid frogs. The
function of this behaviour is unknown but our observations suggest
that it may be triggered by insufficient male effort. Traditionally,
female mate choice in Engystomops has been explained under models
of indirect benefits exclusively. We argue that the prolonged male
activity during nesting could influence female fitness directly. This will
allow the operation of sexual selection via direct benefits.
iguana verde, considerando el efecto de animales callejeros y de la degradación del
paisaje, mediante una evaluación rápida en las riberas del Río Milagro del cantón
Milagro, en Guayas, Ecuador. Se realizaron muestreos en cinco tramos de las riberas,
para poder cuantificar las iguanas, perros y gatos callejeros. Adicionalmente, se
cuantificó la disponibilidad de vegetación y se estimó la contaminación observada
en varias zonas del Río Milagro. Las observaciones realizadas demuestran que las
poblaciones de perros y gatos callejeros no influencian la ocurrencia de iguanas
verdes; sin embargo, un numero representativo de iguanas de la localidad tienden
a aglomerarse en zonas con menor contaminación y mayor vegetación disponible,
áreas que coinciden con los tramos del rio más distantes del centro de la ciudad.
the Amazonian slopes of the Andes of southern Ecuador at elevations
between 1440 and 1970 m. The new species may be distinguished
from other Anolis by external anatomy, mitochondrial divergence
and dewlap colour. We estimate the phylogenetic positions of the
new species using Bayesian analysis of DNA sequence data including
all species of Dactyloa-clade Anolis for which DNA data are available.
Anolis hyacintogularis sp. nov. is sister to Anolis calimae, whereas
Anolis lososi sp. nov. is sister to Anolis williamsmittermeierorum, herein
reported for Ecuador for the first time. Individuals of both new
species were collected within a protected area in southern Ecuador,
Podocarpus National Park, which suggests that at least some populations of these species are well protected.
interactions has long been of interest to evolutionary biologists.
Recently, a distinction between sexually selected traits as ornaments
versus weapons has been advanced. We investigated the behaviour
of an enigmatic lizard with a prominent sexually dimorphic trait in an
effort to describe whether the trait was the product of sexual selection
and further whether it functioned as a weapon or an ornament.
The subject of our study was the Ecuadorian proboscis anole (Anolis
proboscis), a slow-moving cryptic species endemic to the north-western
slopes of the Andes in Ecuador. Males, but not females, of this
species bear a rostral appendage that has been described as an
exaggerated trait resulting from sexual selection. However, a thorough
description of the use of the rostral appendage in social interactions
is lacking. Here, we describe social interactions of this species
during 11 male–female courtships and mating interactions, as well as
three male–male agonistic interactions. We describe four types of
displays by males, many involving the rostral appendage. We found
that the rostral appendage is used as an ornament in social displays
but not as a weapon in combat. We also show that, unlike other
lizards with rostral appendages, male A. proboscis hatch with this
structure already developed.
as an adaptive response to prevent predation and desiccation in dry
environments. Nests are normally laid on ponds, or in underground
galleries, humid forest leaf litter or terrestrial bromeliads. They are built
when males or females beat a foam precursor associated with the egg
masses extruded by the female. The spawning process requires the
synchronic actions of themating pair to obtain a hemispheric nest that
protects the offspring. Herein, we describe the spawning behaviour of
Engystomops pustulatus based on videos from 13 nesting couples from
the lowlands of western Ecuador. Three variables were measured as
indicators of male effort: duration ofmixing events, duration of resting
periods, and number of kicks per mixing event. We consider that not
only male physical effort but also female behaviour influences nest
structure. We suggest that nest building requires prolonged and
intense physical activity by the male as well as the female’s steady
position during spawning and female’s oviposition site selection. Nest
building has two phases. In the first phase, the duration of resting
periods, the duration of mixing events, and the number of kicks
increase and are highly variable. During the second phase the three
variables stabilise until the end. The volume of the nest increased
mainly during the second phase. In four nesting events we observed
kicking movements by the female. To our knowledge, this is the first
time that female kicking has been observed in leptodactylid frogs. The
function of this behaviour is unknown but our observations suggest
that it may be triggered by insufficient male effort. Traditionally,
female mate choice in Engystomops has been explained under models
of indirect benefits exclusively. We argue that the prolonged male
activity during nesting could influence female fitness directly. This will
allow the operation of sexual selection via direct benefits.