In anurans, vocalisations are the main behavioural modality of communication. Hence, the description of acoustic signals in anurans is important for understanding many aspects of their biology. We describe for the first time the advertisement calls for eight glass frog species (Centrolene antioquiensis, ”Centrolene” robledoi, Nymphargus caucanus, N. chami, N. ignotus, N. rosada, N. spilotus, Sachatamia orejuela) and provide additional data on the recently described advertisement calls of Espadarana audax. In addition, we review the current knowledge of advertisement calls for all glass frog species (Centrolenidae). Based on the predominant temporal and the spectral structure, we identified three major types of calls in the family: 1) calls consisting of unpulsed short notes with amplitude modulation, similar to a ‘Tic’, 2) calls consisting of one long note (whistled) without amplitude modulation, similar to a ‘Tii’ and 3) calls consisting of pulsed or pulsatile notes, similar to a ‘Trii’. We mapped these acoustic characters in the context of the evolutionary history of Centrolenidae. Descriptions presented here offer evidence to recognise most centrolenid calls using measurable characters in the field or laboratory. As such, we hope to stimulate future studies based on bioacoustical analysis in this widespread and highly diverse Neotropical clade.

Atelopus laetissimus is an endemic and threatened harlequin frog from the high mountain forests of Sierra Nevada de Santa Marta, Colombia. Knowledge of its reproductive biology is essential for understanding the intraspecific interactions that can help the conservation of Atelopus species. We quantified the energy, measured in body weight, invested by males and females of A. laetissimus for reproduction, and how this energetic investment is related to the survival of individuals and rainfall conditions in habitats during two years (2014 and 2015). Our results show plasticity in terms of reproductive phenology linked to rainfall with short- and long-duration breeding strategies. The first year of this study, 2014, had a precipitation level in accordance with the annual averages at the area. During this time frogs exhibit a short breeding period. Contrary to 2014, 2015 was a year with little precipitation, below the annual averages, which probably facilitated the females’ quick spawning in the creeks and a consequent reduction in the duration of amplexus and low breeding efforts by males. This, in turn, was related to a long breeding period that favors the survival and reproduction of males during the entire year. In 2014 we found a decrease of 25% to 30% body weight of potentially reproductive males, which may be attributed to a prolonged duration of amplectant events.

Previous work has shown that Centrolene savagei is unique among the more than 150 species in the family Centrolenidae in demonstrating large-male mating advantage. However, it is still unknown whether non-random mating in this species is mediated by intrasexual and/or intersexual selection. To disentangle the effect of these selective pressures on mating pattern in this species, we monitored the breeding behavior of individuals in a population located in the department of Quindío, Central Andes of Colombia. We conducted diurnal and nocturnal surveys each weekend between February and July of 2016 in which we documented morphological (i.e., body size) and behavioral (i.e., chorus tenure, parental-care behavior) characteristics of males to determine their relationship with mating success. We corroborated that in this population of C. savagei, larger males obtain a higher number of mates than do smaller males; male body size co-varies positively with chorus tenure and drives this mating pattern. Male body size was not related to higher fertilization efficiency of eggs laid by females, or a higher survival of embryos in clutches cared for by them. In sum, the higher mating success of larger males in the glassfrog C. savagei seems most strongly related to a mechanism of endurance rivalry competition (intrasexual selection) than female choice (intersexual selection) based on egg fertilization efficiency or parental care quality. De las aproximadamente 150 especies de ranas de cristal que conforman la familia Centrolenidae, solo en Centrolene savagei se ha observado que machos grandes tienen más probabilidad de aparearse que machos pequeños. Sin embargo, se desconoce si esto se debe a selección intrasexual y/o selección intersexual. Con el objetivo de describir el patrón de apareo en esta especie de rana de cristal y sus posibles causas, monitoreamos el comportamiento reproductivo de machos y hembras de C. savagei en una población ubicada en el departamento del Quindío, Andes Centrales de Colombia. Se realizó un muestreo diurno y dos nocturnos cada semana durante cinco meses comprendidos entre febrero y julio de 2016, en los cuales documentamos características morfológicas de los machos (e.g., tamaño corporal) y conductuales (e.g., actividad de canto, cuidado parental) para determinar su relación con el éxito de apareo de los individuos. Corroboramos que en esta población de C. savagei, los machos de mayor tamaño corporal están activos un mayor número de noches, lo cual se relacionó significativamente con el número de parejas que obtienen. Sin embargo, este patrón de apareo se debe principalmente a que el tamaño corporal de los machos covaría con el número de noches en que están activos cantando. Por otra parte, el tamaño corporal de los machos no se relacionó con una mayor eficiencia en fertilización de huevos dejados por las hembras ni con una mayor sobrevivencia de los embriones en las posturas que cuidan. Todo lo anterior, indica que en C. savagei los machos grandes exhiben un mayor éxito de apareo que los machos pequeños, debido principalmente a un mecanismo de competencia intrasexual conocido como rivalidad por resistencia, y no a preferencias de apareo por las hembras basadas en beneficios de eficiencia de fertilización de sus huevos o de la calidad de los machos como padres.

Anurans of the family Centrolenidae are a highly diverse clade of Neotropical treefrogs. In the last two decades, glassfrogs have become a model system for studies in ecology and evolutionary biology, in part because their taxonomy and phylogenetic relationships are considered relatively well established. However, there are still many gaps in our knowledge, for example, which morphological characters are important for species delimitation. Consequently, several species complexes in Centrolenidae remain unresolved. Using data on external and internal morphology of adult individuals, tadpoles, advertisement call traits and genetic sequences, we describe a new species of glassfrog (Nymphargus pijao sp. nov.) endemic to Colombia that has been previously missasigned to Nymphargus griffithsi. We include in this description data of three phenotypic characters related to pectoral musculature and testis size, which have been traditionally overlooked in studies about the taxonomy and systematics of glassfrogs. In addition, we present details of a low-cost method implemented in the field to rear tadpoles of the new species. This methodology can solve common problems during the management and care of glassfrogs egg masses and tadpoles, and hence, promotes their description for more species and a better knowledge of the anuran biodiversity in Neotropics.