A decade ago, several publications summarized the state of knowledge on Colombia’s non-marine turtle species, and in 2015, the Colombian Red Book of Reptiles assessed their national conservation status, yielding information to guide research and conservation priorities in this biodiverse country. However, a recent initiative has produced or updated the global extinction risk assessments of Latin American non-marine turtle species. We summarize the current state of knowledge on Colombian populations of these species and propose new research and conservation priorities. The number of threatened turtle species in Colombia and the magnitude of the threats they face are greater than previously thought. Despite advances in research on the Colombian populations of these species, knowledge biases exist across species, with many important aspects of their life histories and population trends poorly understood. Given the speed of habitat loss and degradation, the current levels of exploitation, and the lack of enforcement of the legislation that protects them, we predict continued declines in population densities and distributions. We emphasize the need for more life-history studies and monitoring of population trends and threats to assign a more realistic category of national extinction risk and request the implementation of conservation legislation and the establishment of conservation programs.

Turtle species in the Family Podocnemididae, including the Colombian endemic and critically endangered Magdalena River Turtle Podocnemis lewyana, characteristically present low recapture rates that preclude estimation of population parameters using maximum likelihood modeling. In our 12-year monitoring project with this species, we evaluated changes in relative abundances, proportions of sex/size classes, and individual body sizes and body conditions in a population in four channels in the middle Magdalena River drainage. We also inspected for associations between trends in changes in these variables and differences in hunting pressure and habitat degradation. To inspect for temporal and spatial demographic dynamics, we estimated variation in relative abundances using the Catch Per Unit Effort index, the total number of turtles captured over an entire 5-day sampling period using ten baited funnel traps. Relative abundances and the proportions of sex/size classes were different between sites and years. We found a significant decline in the proportion of females and juveniles over time, along with evidence that the females still present were smaller in body size. Our results support the hypothesis that hunting eliminates adult females from these sites, perhaps also translating into a reduction in recruitment. The lack of evidence of generalized declines in body condition of all size classes suggests that habitat degradation might contribute less to the population declines in this region. Our results also illustrate that even when recapture rates are low, monitoring turtles via standardized trapping may yield insights into the population’s conservation status that other relative abundance indices cannot.

With the exception of the savanna side-necked turtle (Podocnemis vogli) and the redheaded river turtle (Podocnemis erythrocephala), the species within the pleurodire genus Podocnemis have been relatively well-characterized in terms of their temperature-dependent sex determination (TSD) parameters. In this study, we incubated 4 nests of P. vogli (46 eggs) under controlled laboratory incubation conditions to determine whether this species also presents a TSD Ia pattern where males are produced at lower temperatures, characterize the constant temperature producing a 1:1 sex ratio (Tpiv), and document the transitional range of temperatures (TRT) that produces both sexes. The incubation temperatures employed were 29 degrees, 31 degrees, and 33 degrees C (60.15 degrees C). Our results were consistent with the conclusion that P. vogli exhibits a TSD Ia pattern, but it was not possible to document the Tpiv or the superior TRT, because the 29 degrees and 31 degrees C conditions produced all males and even the 33 degrees C condition produced male-biased sex ratios, suggesting a high pivotal temperature for this species. We also documented maternal effects in initial size of the hatchlings, with the female that laid larger eggs producing hatchlings that were larger. Incubation periods of P. vogli were notably longer than those of its congeners incubated under comparable constant temperature and soil moisture conditions. In species of this genus, the TSD Ia pattern suggests that besides the threats these species face from overexploitation and habitat degradation, they also are highly vulnerable to the effects of global warming.

With this analysis, we update the state of knowledge on the species richness, distribution, and conservation status of the turtles of Colombia, both at the national level and regionally within Colombia by hydrological drainages and geopolitical distribution units (departments). The richness patterns and conservation status are analyzed at taxonomic and geographic levels, and the implications of the description of new species on our knowledge of their distribution and conservation status in the country are discussed. Finally, annotations are given on the turtle species that have been introduced into Colombia, translocated within the country, erroneously reported, or deemed to be taxonomically invalid. Our conservative analysis in terms of richness (based upon validated occurrence records) confirms that there are 33 species and two subspecies of turtles in Colombia, of which five are sea turtles and 28 are tortoises or freshwater turtle species. Colombia has 17 genera of chelonians in nine families, so it is second behind Brazil in terms of the number of extant species in South America. The proportion of threatened species in Colombia exceeds 43%, and the threatened species are not evenly distributed among higher taxa or regions. Commonalities were found in the national conservation status assessments for most of the turtle species shared among the five most species-rich countries in South America, including sea turtles and podocnemidids (except for the podocnemidids in Brazil).

We quantified nesting activity and incidence of nest flooding in a population of the Magdalena River turtle (Podocnemis lewyana), which inhabits the climatic equator in northern Colombia, during two dry seasons when beaches formed ("verano"-December to March-and "veranillo"-July and August). Nesting activity was concentrated in the verano period, despite the presence of suitable nesting habitat in both dry season periods. More than half of all nests were harvested by local people, and 42.5% of the nests in both dry seasons that survived harvest were subsequently lost to flooding due to rises in the river to approximately a 4.15 m level. We used this value as a threshold value for the appearance of beaches and inspected a 44-year data base on river levels in this area. The verano and veranillo nesting periods did not differ in terms of opportunities for successful nesting, but there was evidence that the veranillo nesting season has increased significantly in duration in recent years, as well as experienced fewer flooding events. It is not clear why nesting each year is principally concentrated in the verano nesting season, but the evidence that this section of the Magdalena River is drying more in recent years during veranillo may entail a new threat to this population if it implies that non-nesting habitat (adjacent wetlands and channels) might eventually disappear.

We introduce the first contribution to the Herpetological Conservation and Biology Classics in Herpetology category in some years, in which Hykle et al. (2020) provide a synthesis of a governmental report prepared by F.D. Maxwell for the colonial British government concerning the biology, exploitation, and status of the sea turtle species of Burma (now Myanmar). We also provide access to a PDF of the entire Maxwell report. We then discuss the importance of historical accounts of economically important reptile species in general, providing examples of how data they contain may still be particularly relevant to modern studies of their biology and for their conservation.

In freshwater turtles, movements have been shown to be influenced by seasonal changes in water levels, with members of the family Podocnemididae exhibiting some of the longest nesting migrations yet documented. In this study, we quantified linear home range sizes and seasonal movements of the Magdalena River Turtle (Podocnemis lewyana) using capture–mark–recapture and radio-telemetry techniques. We marked 924 turtles and recaptured 7.8% of these individuals one or more times, thereby documenting the movements of 41 juveniles, 13 males, and 18 females. Turtle movements differed significantly among sex/size classes, with males moving more. While 85% of all individuals had estimated linear home range sizes of less than 1 km, one juvenile moved 3.1 km, one female moved 2.5 km, and one male moved 4.8 km. We also obtained data on the movements of six reproductively mature females using radio telemetry. We documented seasonal movements out of channels into wetland or riverine habitats, increasing the estimates of total distance traveled for this sex/size class to a mean of 13.8 km (range = 6.9–18.7 km), with greater displacements documented during low water periods. Together, our results show that individuals of P. lewyana in the middle Magdalena River drainage occupy limited linear home ranges, but that reproductively mature females make extensive displacements during low water periods, presumably related to their need to access nesting beaches in riverine habitats. There are currently no protected areas within the range of this endemic species, but our results argue that any reserve created for protecting this critically endangered turtle must be large enough to cover all of its habitat requirements, including nesting beaches in the dry season that are separated from habitat where they maintain stable home ranges during the remainder of the year.

A rigorous monitoring project provides a means for guaranteeing the conservation or sustainable use of a population, allowing the quantification of changes in its demographic parameters and associating them with spatial and temporal variation in environmental factors. We present the results of a monitoring project of a population of Spectacled Caiman (Caiman crocodilus) conducted from 2013 to 2018 in two contrasting channels in the middle Magdalena River drainage in Colombia. We employed three monitoring methods: nocturnal counts, capturemark-recapture study, and N-mixture models. Although nocturnal counts and N-mixture models are comparable methods, the estimates of population size and of detection probabilities that they provided were different. Both methods, however, agreed in general by indicating that detection probabilities were low and population sizes were large, in comparison to similar estimates from other populations. In the deeper channel with more riparian vegetation and less fishing activity, relative densities were 3.3 orders of magnitude greater than in the other channel, and had a population comprised of a larger proportion of subadult and adult individuals. Low recapture rates precluded estimation of population sizes, survivorship rates, or detection probabilities with the capture-markrecapture data; however, this method provided a more reliable summary of the size distribution of individuals, population sex ratios, and patterns of habitat use. Water depth was the only covariable that significantly influenced detection probabilities. This study is the first application of N-mixture models to estimate population size and detection probabilities in a Caiman population.

We sampled the snake fauna in 13 landscapes along 80 km of highway and in the adjacent vegetation cover in the Colombian Llanos. We registered 119 snakes belonging to 33 species. Traffic levels significantly influenced rates of snake road kill, while adjacent vegetation cover, rainfall seasonality, and landscape structure and composition did not. We classified the species into seven ecological groups based upon foraging strategy, body length, and habitat preferences. Although most of the road-killed species had an active foraging strategy, all of the ecological groups contained some species that were killed on the highway, as well as some species that inhabited adjacent vegetation cover but that were not detected on the highway. The different ecological groups were not associated with different landscape characteristics. Six of the 13 landscapes that presented the lowest species richness of road-killed species had a different ecological group represented by each of the species documented as road kills. Thus, considering the ecological group that a species belongs to provides a complementary analytical approach that permits a fuller understanding of the ecological effects of roads on the functional role of the species in the ecosystem. We recommend focusing mitigation measures on highway sectors with the greater vehicular flow, employing both preventive measures such as posting driver advisories and installing speed radars and conducting environmental education programs to raise awareness of local drivers.

Toe-clipping is an extensively used technique for individual identification of amphibians and reptiles. However, this method might result in negative effects including reduced survival. In this study, we used capture-mark-recapture data obtained from ten different lizard species, including more than one population for two species, to examine whether survival rates varied as a function of the number of toes that were clipped. We used likelihood methods and multi-state models to estimate survival probabilities. Specifically, we tested if the number of clipped toes had an effect on annual survival, comparing survival among groups of individuals that shared the same number of toes that were clipped. We found clear reductions in survival associated with the removal of several toes in seven study sites that correspond to five different species. These represent 37% of all the species and populations that we examined. Therefore, we conclude that this marking method potentially causes severe damage and may lead to biased parameter estimates in ecological studies of lizard species. Whenever possible, toe-clipping should be avoided and replaced by less invasive methods for individual identification.

Durante dos años, incubamos artificialmente bajo temperaturas constantes huevos de Podocnemis unifilis obtenidos del Parque Nacional Natural Cahunarí, Colombia. Una muestra de los neonatos fueron sexados para documentar la temperatura pivotal de esta población (32 °C). Aparentemente, en ambas estaciones de anidación, la mayoría de los nidos en la playa de estudio produjeron individuos de ambos sexos. El remanente de las tortugas obtenidas de las incubadoras por estación reproductiva fue mantenido en cautiverio por un año con el propósito de estudiar los efectos de factores pre y poseclosión en las tasas de crecimiento. En ambos años, documentamos un efecto materno en el tamaño de los huevos y en el tamaño inicial de los neonatos, pero no en las tasas de crecimiento posteriores. Las condiciones de incubación afectaron el tamaño inicial de los neonatos y sus tasas de crecimiento. Los individuos incubados a temperaturas cálidas emergieron con tamaños iniciales menores y luego presentaron tasas de crecimiento mayores. Para el final del primer año, estos individuos fueron significativamente más grandes que sus hermanos incubados a temperaturas más frías, lo cual es consistente con las predicciones de la hipótesis de Charnov y Bull sobre el valor adaptativo de la determinación sexual dependiente de la temperatura. También examinamos los efectos del tipo de dieta, la densidad y las oportunidades de soleamiento en las tasas de crecimiento, y encontramos que las tortugas que recibieron carne en sus dietas crecieron más rápidamente que las que se alimentaron exclusivamente de material vegetal. Las tortugas en la condición de densidad baja alcanzaron tamaños mayores en uno de los dos años del estudio, mientras que el acceso directo a la luz solar para el soleamiento no afectó significativamente las tasas de crecimiento.

This third volume of the annual report on biodiversity in Colombia continues the editorial line that begun in 2014. Using novel analytical and graphic proposals, these reports have the goal of communicating the contents to a broad public, making it available for discussion without sacrificing the quality of information. The challenge of communication continues to be a major part of the institutional project, and the new languages with which we are learning to communicate with society and other institutions are an experiment that we expect to be increasingly gratifying. The report for 2017 is already under construction and it counts on new digital technologies so the power of a colombian vital connection may be entirely expressed. The included content evidences that we are still far away from having a systematic follow-up about most of the topics related to the management of biodiversity and ecosystem services, which is the only way to evaluate the effectiveness of policies and investments made by society. In fact, a limitation that is recognized is that of identifying positive or negative changes that affect different levels of organization of life on this planet; therefore, our global navigation route of the Aichi targets is still to be verified. An additional purpose of this process includes the invitation of all Colombians to contribute in constructing and maintaining basic monitoring indicators for management since it is impossible to identify long-term trends of flora and fauna in the country without the support of institutions, researchers, and citizens. This challenge is immense in a megadiverse country such as Colombia. For this reason, the report will continue to open its pages to experts, and even indigenous peoples or local communities, for them to present their perspectives about environmental change and its effects on biodiversity in a systematic and documented manner. This has the objective of stimulating the commitment of everyone in the management of biodiversity and ecosystem services. The only way of overcoming the risk of extinction is through the active process of social learning in which all sectors assume a part of the complex responsibility in protecting the forms of life of the country, a roughly counted tenth of all creatures on Earth. I thank all the people that contributed in this Report, those who have supported us in the phases of production, and all readers and users, who are the ultimate judges of its utility.

The citations contained in a recent literature review on the freshwater turtle and tortoise species of Colombia were analyzed. Publishing rates on these species have been increasing exponentially since the 1950s, although many of the publications would not be detected using internet-based literature searches. The most common topics of publications were systematics and phylogeography, nesting ecology, and management. In the 1970s and 1980s, the rate of publishing on the ecology and genetics of Colombian populations lagged behind the rate of publishing on these topics for populations of Colombian freshwater turtle and tortoise species located in other countries, but currently the production of the two regions is comparable. Also, in other countries there were trends towards publishing more over time in English and in journals with higher impact factors, but these trends were not significant for publications on Colombian populations. In Colombia, a disproportionate number of studies have been published on large-bodied species that face conservation problems. We argue that future studies of already well-studied Colombian species should focus on evaluating the effectiveness of management programs, and priority also should be given to increasing our knowledge of the many poorly-studied species in the country, especially those currently classified by the IUCN as data deficient (DD).

Large initial body size and rapid early growth rate are important in many species, both because predation rates decline as individuals grow and because females that attain a larger adult body size are more fecund. To identify possible factors contributing to size and growth rate variation in hatchling green iguanas, we artificially incubated six clutches at three constant temperatures to test for effects of incubation temperature and/or clutch effects on initial size and growth rate. Higher incubation temperatures resulted in significantly shorter incubation periods but did not influence initial body size. There were significant differences among clutches in egg size, and also in initial hatchling body size, even after correcting for differences in egg size among clutches. A subset of hatchlings from each nest was reared in semi-natural conditions for four months, with individuals from the high incubation temperature condition exhibiting the slowest longer-term growth rates. No clutch effects were detected in the growth rate analyses. The observed variation in early growth rate of juvenile iguanas seems to be selectively important and this variation may be due in part to the conditions the eggs experience during incubation, but clutch effects in this study were limited to egg size and initial hatchling body size variation, but were not found for subsequent growth rates.

The citations contained in a recent literature review on the freshwater turtle and tortoise species of Colombia were analyzed. Publishing rates on these species have been increasing exponentially since the 1950s, although many of the publications would not be detected using internet-based literature searches. The most common topics of publications were systematics and phylogeography, nesting ecology, and management. In the 1970s and 1980s, the rate of publishing on the ecology and genetics of Colombian populations lagged behind the rate of publishing on these topics for populations of Colombian freshwater turtle and tortoise species located in other countries, but currently the production of the two regions is comparable. Also, in other countries there were trends towards publishing more over time in English and in journals with higher impact factors, but these trends were not significant for publications on Colombian populations. In Colombia, a disproportionate number of studies have been published on large-bodied species that face conservation problems. We argue that future studies of already well-studied Colombian species should focus on evaluating the effectiveness of management programs, and priority also should be given to increasing our knowledge of the many poorly-studied species in the country, especially those currently classified by the IUCN as data deficient (DD).

This study aimed to document demographic parameters of an Andean dart frog, Andinobates opisthomelas. We used a photo-identification method to recognize recaptured individuals during a six month study of a population on a small island in a reservoir in the Cordillera Central of Colombia. Reproductively active males were identified based upon the presence of vocal sacs or observed calling or parental care behaviors (carrying from one to three tadpoles on their backs). Minimum size at first reproduction for males was estimated at 12.9 mm snout-vent length. Only 4% of captured individuals were smaller than this size; the remaining individuals were classified as either reproductively active males or other adults. The survival rates and detectabilities of these two groups were compared in both wet and dry season periods using maximum likelihood model fitting methods. Survival rates did not differ between groups but was related to body size, with smaller adult individuals having lower survival rates. Reproductively active males had higher detectabilities than other adult individuals, and both classes exhibited higher detectabilities in larger individuals and in the dry season sampling periods. Herpetologists are encouraged to use methods that permit decomposition of encounter rates into their component parameters (survival rate and detection probability) to facilitate identification of factors influencing population dynamics and permit meaningful comparisons among studies.

Esta tercera entrega del reporte anual de la biodiversidad en Colombia profundiza en la linea editorial iniciada el ano 2014 mediante nuevas propuestas analiticas y graficas, con la intencion de garantizar que la informacion llegue a todos los publicos y pueda ser discutida de manera amena sin sacrificio de calidad. La apuesta comunicativa sigue siendo central en el proyecto institucional y los nuevos lenguajes con los que estamos aprendiendo a conversar con la sociedad y las instituciones son un experimento que esperamos sea cada vez mas satisfactorio: ya estamos construyendo la version 2017 con el apoyo de las nuevas tecnologias digitales de manera que la potencia de la conexion vital colombiana se exprese en toda su capacidad. Por los contenidos es evidente que aun distamos mucho de tener una capacidad de seguimiento sistematico para la mayoria de temas relativos a la gestion de la biodiversidad y los servicios ecosistemicos, la unica manera de evaluar si las medidas de politica y las inversiones que realiza la sociedad estan teniendo los efectos deseados. De hecho, parte de las limitaciones reconocidas por robustamente los cambios positivos o negativos que afectan los diferentes niveles de organizacion de la vida planetaria, por lo cual las mismas metas de Aichi, nuestra carta de navegacion global, estan pendientes de verificacion. Un proposito adicional de este proceso es la invitacion a todos los colombianos para contribuir con la construccion y alimentacion de los indicadores basicos de seguimiento a la gestion, ya que es imposible identificar las tendencias de largo plazo en que estan inmersas la flora y fauna colombianas sin el apoyo de las instituciones, los investigadores y los ciudadanos: en el pais de la megadiversidad, el reto es inmenso. Por este motivo, este reporte ira abriendo sus paginas a expertos, incluso indigenas o de comunidades locales, para que presenten de manera sistematica y documentada sus perspectivas del cambio ambiental y sus efectos en la biodiversidad, con el animo de promover el compromiso de todos en su gestion. La unica manera de superar el riesgo de extincion es mediante un activo proceso de aprendizajes sociales que haga que todos los sectores asuman una parte de la compleja responsabilidad que significa proteger todas las formas de vida del pais, una decima parte mal contada de las planetarias. Agradezco a las decenas de personas que contribuyeron con este reporte, a quienes nos han apoyado en todas las etapas de produccion y a sus lectores y usuarios, quienes son en ultimo termino los jueces de su utilidad.