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La tortuga carey, Eretmochelys imbricata, se encuentra a nivel global en peligro crítico de extinción, y la información demográfica en el Océano Pacífico Oriental es limitada. Por esta razón, esta investigación evalúa las tasas de crecimiento somático en una agregación de individuos inmaduros de tortuga carey empleando el método de captura-marca-recaptura en los arrecifes coralinos de Playa Blanca y la Azufrada en el Parque Nacional Natural Gorgona, Colombia. Entre 2004 y 2018 se realizaron 89 capturas de 49 individuos de tortuga carey. El largo curvo del caparazón promedio (LCC) obtenido fue de 41,6 cm (rango 32-58 cm) y el largo recto del caparazón promedio (LRC) fue de 39,1 cm (rango 30,0-54,1 cm), lo que muestra que estos arrecifes son áreas de forrajeo importantes para individuos inmaduros de esta especie. El índice de condición corporal promedio fue de 1,3 (rango 1,0-1,5). Esto sugiere que las condiciones ambientales mantienen en buen estado la salud de esta agregación. Usando el modelo de crecimiento de von Bertalanffy y estableciendo una talla máxima (L∞) de 63 cm de LCC (donde se obtiene el menor coeficiente de variación), se estimó una k de 0,081 y una tasa anual de crecimiento promedio de 1,5 ± 1,8 cm/año. Esto indica que los individuos en esta agregación estarían alcanzando una LCC de 63 cm entre los 33 y 34 años, talla cercana a la de madurez sexual en la región del Pacífico oriental (aproximadamente 66 cm LCC). Lo anterior ratifica la vulnerabilidad de esta especie debido a las lentas tasas de crecimiento somático y madurez sexual tardía. Se sugiere que los esfuerzos de conservación para esta especie deben ser a largo plazo para procurar su recuperación, en vista de que especies con estas características tienden a expresar tasas de crecimiento poblacional muy bajas.

Turtles and tortoises (chelonians) have been integral components of global ecosystems for about 220 million years and have played important roles in human culture for at least 400,000 years. The chelonian shell is a remarkable evolutionary adaptation, facilitating success in terrestrial, freshwater and marine ecosystems. Today, more than half of the 360 living species and 482 total taxa (species and subspecies combined) are threatened with extinction. This places chelonians among the groups with the highest extinction risk of any sizeable vertebrate group. Turtle populations are declining rapidly due to habitat loss, consumption by humans for food and traditional medicines and collection for the international pet trade. Many taxa could become extinct in this century. Here, we examine survival threats to turtles and tortoises and discuss the interventions that will be needed to prevent widespread extinction in this group in coming decades.

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.

Incubation temperature is a factor that can affect several traits in turtles such as body size, growth, shape, and sex in species with temperature-dependent sex determination. A clear understanding of these effects is particularly important in threatened species such as the red-footed tortoise (Chelonoidis carbonarius), classified in Colombia as Vulnerable mainly due to the capture of wild individuals to be kept as pets. A previous study on the effect of incubation temperature on sex determination concluded that constant temperatures of 31°C and 33°C are lethal to C. carbonarius embryos and that a temperature of 29°C produces 100% females. Although this showed that C. carbonarius has a temperature-based sex determination mechanism, its full reaction norm is still unknown. To fill in the gaps, we incubated 160 eggs from 47 nests at constant temperatures of 24°C, 26°C, and 28°C. The hatching success rates were 55%, 53%, and 60%, respectively, with extremely long incubation periods of 213, 164, and 138 d. Of the 75 neonates obtained, 58 reached 8 mo of age, at which time 45% (n = 26) were sexed. The sexual proportions (% males) obtained were 88.9%, 60%, and 0% from the 24°C, 26°C, and 28°C treatments. From the calculated thermal reaction norm, we estimated that the pivotal temperature is 26.05°C (95% CI = 25.31–26.69) and the transitional temperature range is from 24.34°C to 27.77°C. Incubation temperature also affected incubation period and hatchling body size and growth. Additionally, we found a significant effect of female body size and mass on egg size and mass, supporting a fecundity selection hypothesis of body size. Finally, we inspected hatchlings for sexual shape dimorphism using geometric morphometrics. We found significant differences in anal notch and plastron shape at 7 d of age, but only differences for anal notch at 1 and 2 mo of age. However, the statistical signal was weak and the results varied with age; thus this sexing technique was unreliable. Given the low critical thermal maxima for embryo survivorship (31°C or less), together with a 100% feminizing temperature of 27.9°C, global climate change coupled with deforestation constitute imminent threats to this species due to demographic impacts such as low recruitment rates and skewed primary sex ratios.

Understanding reproductive biology and embryonic development is vital to guide conservation programs for endangered species. The Red-footed Tortoise, Chelonoidis carbonarius, is a vulnerable species for which the sex determination mechanism and the transitional temperatures range are unknown. In an attempt to obtain this information, we incubated 145 eggs (38 nests) at 3 constant temperatures: 29°C, 31°C, and 33°C. All embryos incubated at 33°C (n = 49) died during the first third of the incubation period. Of the eggs incubated at 31°C (n = 47), only 10.6% hatched, and 2.12% of the embryos showed malformations of the carapace, head, or legs. Of the eggs incubated at 29°C (n = 49), 52% hatched successfully with 10.2% exhibiting body malformations. From the 30 neonates obtained, we were able to sex 20 individuals by laparoscopies, 2 by gonads histology, 1 was impossible to identify because of the small sizes of the gonads at the time of death, and the remaining were released back to their tortoise ...

A tres hembras adultas de Podocnemis unifilis capturadas en una playa de anidación en el río Caquetá, departamento del Amazonas, Colombia, se les colocó radiotransmisores con el propósito de registrar sus desplazamientos. Aunque estos individuos ocasionalmente realizaron desplazamientos rápidos contra y en dirección de la corriente del río, se observó una tendencia a permanecer en la misma área dl río durante varios días o semanas consecutivos. Cuando el nivel del río bajó, las tortugas permanecieron cerca a las playas o en otras áreas protegidas de la corriente principal. Durante los tres meses siguientes a su liberación, ninguna de las tres hembras se dispersó más de 6 km a partir de la playa de captura. Aunque no fue posible documentar los desplazamientos realizados por estos individuos una vez se internaron en la varzea del bosque durante el período anual de inundación, una de las hembras fue relocalizada nueve meses después, cuando el nivel del río regresó a su cauce. Esta reapareció cerca al punto en que se ubicó la última vez, y luego se desplazó a la misma playa donde fue capturada inicialmente. Para las otras dos hembras, sólo fue posible documentar sus desplazamientos hasta el momento en que se internaron en el bosque inundado. Se discuten las implicaciones de estos resultados con respecto a los programas de manejo para esta especie, amenazada con la extinción.

La playa de La Cuevita, con una extensión de 8 km, localizada en el corregimiento del Valle, municipio de Bahía Solano, Chocó, es una de las principales playas de anidación de Lepidocheys olivacea identificadas en el Pacífico colombiano. Durante la estación reproductiva de 1998 (de agosto a diciembre) registramos 113 arribos y trasladamos a un corral de protección (tortugario) 91 nidos con un total de 8.918 huevos. Las hembras presentaron una tendencia significativa a anidar en el primer sector de esta playa (kms 0-2) y en la zona de lavado. No encontramos un pico aparente de anidación durante la temporada reproductiva. El éxito de eclosión para los primeros 59 nidos trasladados fue 81.5% y el éxito reproductivo fue 79%. Monitoreamos la temperatura de incubación de diez de estos nidos hasta la fecha de eclosión de los mismos. Tanto la temperatura promedio de incubación a lo largo de todo el periodo de incubación, como el promedio de la temperatura únicamente durante el periodo crítico de incubación, mostraron fluctuaciones diarias por encima y por debajo de la temperatura umbral reportada para la población de tortuga golfina anidante en Playa Nancite, Costa Rica. Inspeccionamos histológicamente las gónadas de una muestra aleatoria de diez juveniles de diez nidos con registro de temperatura (n =100). En aquellos expuestos a temperaturas promedio menores de 29 ºC únicamente obtuvimos machos. Encontramos un porcentaje de hembras entre 40 y 70 bajo temperaturas de incubación entre 30 y 31 ºC. Se presentó un nido atípico con temperatura promedio de incubación de 30.5 ºC presentó una proporción sexual de 1:1. Se discute la necesidad de estimar la proporción sexual de los neonatos que eclosionan de nidos naturales en esta playa. De acuerdo con estos resultados, la forma en que se han manipulado los nidos y las actuales condiciones de incubación en el tortugario probablemente han favorecido la producción de machos durante años en una proporción de por lo menos 3:1, lo cual puede ir en detrimento del mantenimiento de esta población. Igualmente ¡, se sugiere que en futuros estudios en esta playa se determine la temperatura umbral para esta población con el fin de que si es necesario incubar los nidos artificialmente en el tortugario, como consecuencia de la elevada tasa de depredación de los nidos naturales en esta playa, se haga bajo condiciones muy similares a las naturales, para minimizar otras posibles alteraciones biológicas.

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.

La Playona, una extensión de 12 km de playa localizada dentro del golfo de Urabá en el extremo noroccidental de Colombia, mantiene la principal colonia de anidación de la tortuga caná (Dermochelys coriacea) en el país. Durante la estación reproductiva de 1998, en los 3 km de esta playa que fueron monitoreados interceptamos 189 arribos de hembras, los cuales resultaron en 162 posturas. Ciento cuatro de estas hembras no estaban aparentemente marcadas, y logramos marcar con placas monel 71 de ellas. Recapturamos 39 hembras marcadas, de las cuales 34 fueron hembras reanidantes marcadas por nosotros en esta estación y cinco fueron marcadas en otros años. El tiempo modal de reanidación de una misma hembra fue aproximadamente diez días y la frecuencia máxima de reanidación durante la estación fue de seis veces. La estación de anidación se extendió desde finales de febrero hasta principios de julio, con un pico entre el 10 de abril y el 10 de mayo. El promedio de la longitud curva del caparazón de las hembras fue 150.9 cm y del ancho curvo 110.8 cm. El promedio del tamaño de la nidada fue 115.5 huevos, de los cuales el promedio de huevos infértiles por nido fue 30%. Los huevos fértiles tuvieron un promedio en diámetro de 5.4 cm y un de peso promedio de 87.1 g. Se presentó una anidación significativamente mayor en la zona media de la playa, con 71.3% de los nidos. Trasladamos a un corral dentro de la misma playa 88 nidos y protegimos 10 nidos naturales in situ. El promedio del periodo de incubación para los nidos naturales fue 58.4 días y 59.2 días para los trasladados: El porcentaje de eclosión de los nidos naturales fue 68.5%. En comparación, el porcentaje de eclosión de los nidos trasladados fue sólo 28.0%. En total, de los 5.308 huevos fértiles que monitoreamos esta estación. Sólo logramos liberar al mar 1.651 neonatos (31.1%), y los demás se perdieron tanto por causas naturales como antrópicas. Los resultados de este estudio destacan la importancia de esta playa en el ámbito internacional, considerando la densidad de hembras anidantes y que tan sólo se monitorearon tres de los 12 km de la playa. Igualmente, muestran cómo las técnicas de traslado que se han empleado con esta población durante varios años producen procentajes muy elevados de mortalidad, y aunque el método de traslado en bolsa fue más eficaz que el de nevera, el éxito de eclosión de los nidos naturales fue muy superior al de los nidos trasladados. Con base en estos resultados, se diseñó un plan de manejo para 1999 que permitiera proteger in situ con la esperanza de aumentar el éxito reproductivo de la estación y no modificar las características de la incubación.

Cuantificamosla variación en el tamaño y forma del cuerpo y cabeza de Bolitoglossa vallecula en cuatro poblaciones de la Cordillera Central de Colombia. Dos de estas cuatro poblaciones ocurren en simpatría con B. ramosi una especie de salamandra ecológicamente similar que podría potencialmente competir con B. vallecula por recursos alimenticios. En ninguna de las poblaciones encontramos evidencias de dimorfismo sexual en el tamaño o forma de la cabeza, por lo tanto los datos de hembras y machos fueron agrupados. Las poblaciones difirieron significativamente en el tamaño promedio del cuerpo, pero esta variación no estuvo asociada con la elevación. Cuantificamos seis características de la forma de la cabeza asociadas con la morfología de la misma y las analizamos utilizando las proporciones de cada variable sobre la media geométrica, debido a que esta metodología es la más utilizada en la literatura para describir conformación mientras se controla por el efecto del tamaño. Una de las poblaciones simpátricas con B. ramosi (Bello) presentó diferencias significativas en la conformación de la morfología de la cabeza cuando se comparó con las poblaciones alopátricas, mientras que la otra población simpátrica no. Aunque en este trabajo la evidencia de desplazamiento de caracteres en respuesta a la competencia ecológica no es concluyente, este análisis destaca áreas de investigación que vale la pena adelantar en el futuro.

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.

This study aimed to document demographic parameters of an Andean dart frog, Andinobates opisthomelas. We used a photoidentification 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. R...

Species with temperature-dependent sex determination (TSD) are more vulnerable to climate change than species with genetically based sex determination because an increase in average environmental temperature could lead to biased offspring sex ratios. In TSD species, the relationship between sex ratio and constant incubation temperature is characterized by two parameters: the pivotal temperature (Tpiv) and the transitional range of temperature (TRT) that produces both sexes. Species with variation in either of these parameters should have more potential to adapt to new climatic conditions, therefore putting them at lower risk to global warming. In this study, we incubated eggs of the turtle Podocnemis lewyana (Testudines: Podocnemididae) from two geographically isolated populations (Magdalena and Sinu rivers) under controlled microclimatic conditions to corroborate the TSD pattern previously reported for this species and to estimate the degree of inter- and intrapopulation variation in Tpiv and TR...

We conducted a short study in the Bojonawi Private Nature Reserve (Vichada department, Colombia) in three types of aquatic macrohabitats to characterize habitat use, population structure and reproductive phenology of Podocnemis vogli during one reproductive season. We also reevaluated the degree of sexual dimorphism in this species. To maximize capture rates, we used three methods: funnel traps, trammel nets, and manual capture. Only the funnel traps could be used in a standardized manner in all three macrohabitats. We captured 149 individuals in all age/size classes and obtained 11 recaptures. Since we were able to standardize sampling effort with the funnel traps in all macrohabitats, we compared habitat use and class structure among habitats during this reproductive season. There were no significant differences among the three macrohabitats in terms of relative abundances or size class distributions, but sex ratios differed, with an excess of males in the river and females in the lagoon. As with other congeners, P. vogli is a sexually dimorphic species where females attain larger sizes. In this study we documented that pre-cloacal tail length and nail length on the anterior third toe are the most useful secondary sexual characteristics for sexing subadult and adult individuals. Some females larger than 22 cm straight-line carapace length had calcified eggs in their oviducts. This species is abundant within the reserve and appears to be a habitat generalist, including the use of large rivers. More extensive and intensive monitoring is needed to document specific class survivorship rates, detectabilities and population dynamics.

We conducted a four-year study of the life history parameters of the endangered freshwater turtle Podocnemis lewyana (Testudines: Podocnemididae) in four channels connecting wetlands to the Magdalena River in northern Colombia. Using capture–mark–recapture techniques, we documented body size growth rates, sex ratios, and size class distributions, and estimated survival rates for juveniles and adults. We also used body size/clutch size and body size/track width correlations to estimate the body sizes of females that nested in beaches in the Magdalena River near the study sites. The body size at first nesting (30 cm straight-line carapace length) was comparable to the estimate obtained by inspecting the reproductive tracts of 70 females using a sonograph. Growth rate analyses showed adult males to be smaller than adult females with an estimated size at sexual maturity of 20 cm straight-line carapace length. Females begin nesting at 5–6 years of age and may lay up to four clutches annually with a mean clutch...

We review the current practices of podocnemidid turtle conservation programs in South America and summarize the direct and indirect negative consequences that some of these practices may have on the populations we are attempting to manage. We argue that programs that only focus on nest transfer and head-starting as their conservation strategies would be better served by redirecting their efforts toward the protection of subadults and adults and in conducting monitoring programs designed to evaluate the impact of their management practices. Also, we make suggestions for other ways that the management of podocnemidid populations may be improved without resorting to manipulative ex situ practices that may well do more harm than good.

In oviparous species, preovulatory maternal effects such as investment in yolk quantity and composition or levels of yolk steroid hormones might potentially affect hatchling body sizes, growth rates, performance, and sex in species with temperature-dependent sex determination. We investigated the effects of egg mass and levels of testosterone and 17β-estradiol in the yolk on the phenotypes of hatchling Magdalena River Turtles (Podocnemis lewyana) in three populations in the Magdalena River drainage of northern Colombia. We hypothesized that, under homogeneous incubation conditions, the differences documented among clutches would be attributable to familial effects, caused by either heritable genetic factors or preovulatory maternal effects. Eggs were incubated artificially at the pivotal temperature for the species (33.4°C) and hatchlings were reared in the laboratory for 2 mo. Two eggs from each clutch were tested for testosterone and 17β-estradiol levels. Sex ratios, hatchling size, mass, and...

Using high throughput sequencing we obtained a large number of microsatellites from Podocnemis lewyana , an endemic turtle from northwestern South America. We used 454 Genome Sequence FLX platform of sheared genomic DNA from randomly sampling approximately 17% of the haploid genome. We identified 86,501 reads (8.1% of all reads) that contained our definition of microsatellite loci. AC and TC were the most abundant motifs in the P. lewyana genome. TGC and AAAC were most abundant tri and tetra-nucleotide motifs respectively. 72.7% of microsatellite reads had flanking sequence regions suitable for primer design and PCR amplification. We validated the identified potentially amplifiable loci (PAL) and tested for polymorphism by selecting 15 loci corresponding to tetranucleotides. Twelve loci showed polymorphism in eight individuals. These findings demonstrates that microsatellite detection using next-generation sequencing is an efficient way of getting a lot of loci for listed taxa and in turn will have a large impact on future genetic studies aiming to understand and implement conservation plans for this highly threatened freshwater turtle.

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.

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.

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). RESUMEN Analizamos las referencias incluidas en una reciente revisión literaria sobre el estado de conocimiento de las tortugas continentales de Colombia. La tasa de publicaciones sobre estas especies ha incrementado exponencialmente desde los años 1950s, aunque muchas de éstas no podrían haber sido detectadas usando búsquedas de literatura por internet. Los tópicos más comunes de las publicaciones fueron sistemática y filo-geografía, ecología de anidación, y manejo. En los años 1970s y 1980s, la tasa de publicaciones sobre temas de ecología y genética de poblaciones ocupando el territorio colombiano, estuvo por debajo de publicaciones sobre estos dos tópicos con poblaciones de las mismas especies en otras regiones de Suramérica. Sin embargo, actualmente la producción en ambas regiones es comparable. En otros países, detectamos una tendencia temporal significativa de publicar cada vez más en inglés y en revistas de mayor impacto; esta tendencia no fue significativa para las publicaciones sobre poblaciones de tortugas colombianas. En Colombia, un número desproporcionado de las publicaciones son sobre especies de tamaños grandes que enfrentan problemas de conservación. Argumentamos que estudios futuros de las especies de tortugas continentales de Colombia relativamente bien conocidas, se deberían enfocar en evaluar la efectividad de los programas de manejo, y también debemos dar prioridad a investigaciones que aumenten el estado de conocimiento de las especies de tortugas continentales poco estudiadas en el país, especialmente de aquellas que actualmente están categorizadas por la UICN como con datos deficientes (DD).

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.

We present a review and analysis of the conservation status and International Union for Conservation of Nature (IUCN) threat categories of all 360 currently recognized species of extant and recently extinct turtles and tortoises (Order Testudines). Our analysis is based on the 2018 IUCN Red List status of 251 listed species, augmented by provisional Red List assessments by the IUCN Tortoise and Freshwater Turtle Specialist Group (TFTSG) of 109 currently unlisted species of tortoises and freshwater turtles, as well as re-assessments of several outdated IUCN Red List assessments. Of all recognized species of turtles and tortoises, this combined analysis indicates that 20.0% are Critically Endangered (CR), 35.3% are Critically Endangered or Endangered (CR+EN), and 51.9% are Threatened (CR+EN+Vulnerable). Adjusting for the potential threat levels of Data Deficient (DD) species indicates that 56.3% of all data-sufficient species are Threatened. We calculated percentages of imperiled species and modifi...

We studied various aspects of the reproductive biology of the Magdalena River turtle (Podocnemis lewyana) during 2 nesting seasons in 2 locations in the Mompos Depression in northern Colombia. We monitored 53 nests; 22 that completed incubation in situ, 24 that were transferred to protected areas (transferred nests), and 7 that were constructed using eggs removed from females that had been consumed by local people (“oviductal” nests). For each nest, we registered the oviposition date, distance to the nearest body of water, soil type, vegetative cover, exposure to sunlight, depth to the first egg, and maximum depth of the nest chamber. We also quantified egg dimensions and clutch sizes, mean incubation temperatures and duration of incubation periods, hatching success rates, and sex ratios. Most nests were located within 15 m of the shoreline, in open or grassy areas with permanent exposure to sunlight, and in sandy soils. The 3 nest types (natural, transferred, and oviductal) did not differ in hat...

Two populations of the endangered Magdalena River turtle, Podocnemis lewyana, separated by 55 km in the Mom-pos Depression were sampled to quantify levels of genetic variation and inspect for evidence of genetic structure. Allozyme analyses resolved 22 presumptive gene loci, but only one resulted polymorphic. Genotype proportions at this locus departed from those expected under Hardy-Weinberg equilibrium, showing heterozygote deficiencies in both populations. However, allele frequencies at the locus did not differ between the two sites. The level of genetic variability documented is one of the lowest yet reported for a turtle species, and may reflect either a historical or recent bottleneck event. The lack of evidence for genetic structure suggests gene flow among the sites, at least historically, but the heterozygote deficiencies at each site also imply that inbreeding may be occurring presently within each deme.

During two nesting seasons we monitored 19 naturally incubated nests of Podocnemis lewyana obtained from two sites in the Mompos Depression of northern Colombia. We incubated another nine nests in the laboratory under similar humidity conditions, but at six different temperatures. We sexed the hatchlings obtained from all nests to confirm for the first time the occurrence of temperature-dependent sex determination in this species and quantify sex ratios and the pivotal temperature for this population. In both nesting seasons, the majority of the nests in the field produced hatchlings of both sexes, but sex ratios differed between study beaches/years. The pivotal temperature documented (33.4°C) appears to be among the highest reported for a turtle species. Incubation conditions in the naturally incubated nests also influenced hatching success rates and incubation periods, but not hatchling size or weight. Hatchlings obtained from the nests incubated in the laboratory were reared for one month in o...

We obtained evidence of the continued presence of Podocnemis lewyana in 18 different sites within the Magdalena River drainage of northern Colombia. However, abundances at most sites were low, even in areas where the species had previously been reported as common. Although hunting of adults is no longer commercially viable, local people consume individuals that are captured incidentally while fishing. Hunting of eggs during the incubation period each year continues to be intensive. Turtle abundances were negatively related to human densities throughout this area. In the Chicagua River, where turtle abundances were highest, we conducted standardized shoreline censuses of basking adults and documented abundances of approximately 6 individuals/km2. Turtles often basked on mud banks, beaches, or emergent logs in aggregations made up of all size classes. Pilot trapping efforts also succeeded in capturing all size classes of turtles, which suggests that more intensive monitoring programs would be feasi...

Allozyme analyses were conducted on samples obtained from Trachemys scripta callirostris adults harvested in the Mompos Depression of Colombia. Genetic variability was low and there was no apparent genetic structure at either the micro- or macrogeographic scale, which contrasts markedly with the results of previous studies of a Trachemys population in the southeastern United States. These results have management implications for this subspecies and also suggest the need for further studies of the population genetics and systematics of other tropical Trachemys populations.

We evaluated morphometric variation and reproductive effort in Trachemys callirostris callirostris females from nine populations in the Mompos Depression of northern Colombia. Two hypotheses were evaluated: (1) phenotypes of nesting females co-vary according to geographic distances among sites and/ or specific environmental conditions at each site, and (2) female body size influences their reproductive potential and offspring characteristics. Populations were shown to differ in both mean female body size and body shape, with differences more related to local habitat characteristics than to geographic distances among sites. Larger females occurred in sites with higher annual precipitation and lower hunting pressure. Female size was highly correlated with clutch size and mass. Although habitat characteristics affected female size, habitat alone was not a predictor of reproductive potential. Specific habitat conditions and hunting both influence female phenotypes in this region and thereby also influence key demographic parameters, which have clear conservation implications for this highly exploited species.

Nest-site selection by female Trachemys callirostris callirostris was studied on an island in the Pijino wetland of the Mompos Depression of Colombia. We quantified distances of nests to the shoreline and compared vegetative cover and soil types at nest locations and at randomly selected points on the island. Nests sites were concentrated in the first 5 m from the shoreline and were always located under vegetative cover. Such cover might reduce thermal stress to nesting females, lower the probability of nest detection by predators, and buffer the incubating eggs from environmental extremes. Females preferentially nested under water hyacinth, but it was not clear whether they selected directly for this vegetative cover type or simply preferred dirt substrates where it dominated, because dirt soils contained higher humidity.

Northwestern South America harbors one of the richest herpetofauna in the world. The connection among several biogeographic provinces along with climatic and orographic complexity makes this region an important contributor to the Neotropical biodiversity. Despite of this importance, the amphibian and reptile fauna in this area remains largely unknown as few herpetological collections has been made in recent decades. Motivated by this, the Herpetological Museum at the Universidad de Antioquia (Medellín, Colombia) has been increasing the collection in the last 16 years to better understand the herpetofaunal diversity and thus contribute to ecological, systematic, biogeographic and conservation research in the Neotropics. Here, we present the results of this effort and highlight how future collection will impact our understanding of the Neotropical herpetofauna.

We quantified total mercury concentrations in eggshells, egg yolks, and embryos from 16 nests of the Colombian Slider (Trachemys callirostris). Nests were collected in different stages of development, but estimated time of incubation in natural substrates was not correlated with mercury levels in the eggs, suggesting that mercury was not absorbed from the substrate, but more likely passed on to the embryos during folliculogenesis by the reproductive females who had bioaccumulated the mercury from environmental sources. Mean mercury concentrations were higher in embryos than in eggshells or egg yolks, indicating that embryos also bioaccumulate mercury present in other egg tissues. Intra-clutch variation in egg yolk mercury concentrations was relatively high. Egg yolk mercury concentrations were not associated with any of the fitness proxies we quantified for the nests (hatching success rates, initial neonate sizes and first-month juvenile growth rates). After five months of captive rearing in a mercury-free laboratory environment, 86 % of the juveniles had eliminated the mercury from their tissues.

The olive ridley (Lepidochelys olivacea) is the most common sea turtle to nest in Colombia. El Valle beach is considered the most important nesting beach for this species in South America. Intensive direct capture of nesting females and egg poaching for consumption and local commercial purposes has been a common practice for years. We conducted an analysis of the nesting ecology of the olive ridley on El Valle beach in the northern Pacific of Colombia in 2008. A total of 164 clutches were transferred to an artificial hatchery for protection. The peak of nesting occurred from the second half of August until the end of September, accounting for 64.6 % of all nests. Along the beach, the section most frequently used was Section 3, with 26 % of the nests. The nests were laid mainly in zone 3, 69%. We encountered 55 nesting females and marked 46 of them. Mean CCL was 64.9 ± 2.4 cm (± 1 SD) and mean CCW was 68.6 ± 2.6 cm. Females laid on average of 87.3 ± 14.2 eggs per clutch. We recorded two nesting events per female, with a mean inter-nesting period of 18.8 ± 4.2 days. The reproductive output for the season was 181.5 ± 34.8 eggs / female. Mean hatching success was 81.1 ± 12.1% and mean emergence success was 77.6 ± 12.7%. The incubation period was 65 ± 4.7 days. Our study is a valuable contribution to knowledge of the reproductive ecology of the olive ridley population regionally and globally. Ecologia de anidacion de la tortuga golfina ( Lepidochelys olivacea ) (Cheloniidae) en la Playa El Valle, Pacifico Norte, Colombia En Colombia, la tortuga golfina (Lepidochelys olivacea) es la mas comun de las tortugas anidantes. La playa El Valle es considerada la mas importante para anidacion en Suramerica. La intensa captura de hembras y saqueo de huevos para consumo y comercio local ha sido una practica comun por anos. Realizamos un analisis de la ecologia de anidacion de la tortuga golfina en la Playa El Valle, Pacifico Norte, durante la temporada de 2008. Un total de 164 nidadas fueron transferidas a viveros de proteccion. El pico de anidacion ocurrio durante la segunda quincena de agosto y septiembre con un 64,63 % de las posturas. A lo largo de la playa, el sector 3 presento la mayor frecuencia de anidacion con 26 %. Los nidos fueron desovados principalmente en la zona 3, con 69 %. Encontramos 55 hembras y 46 fueron marcadas. El LCC fue (promedio± DE: 64,9 ± 2,4 cm) y ACC fue (promedio ± DE: 68,6 ± 2,6 cm). Las hembras desovaron 87,3 ± 14,2 huevos por nidada. Registramos dos eventos de anidacion por hembra, con un intervalo de (promedio ± DE: 18,8 ± 4,2 dias). El producto reproductivo fue (promedio ± DE: 181,5 ± 34,8 huevos por hembra). El promedio en exito de eclosion fue 81,1 ±12,1% y de emergencia 77,6 ±12,7%. El periodo de incubacion fue (promedio ± DE: 65 ± 4,7 dias). Nuestros datos son una valiosa contribucion al conocimiento de la ecologia reproductiva de la poblacion de tortugas golfina regional y globalmente.

Durante la excavación de un nido de la hormiga cortadora Acromyrmex octospinosus, descubrimos una nidada de la serpiente Stenorrhina degenhardti de la familia colubridae. Tanto los huevos como la masa del nido de hormiga fueron transferidos al laboratorio de la Universidad de Antioquia para ser mantenidos en cautiverio. Las hormigas no solo toleraron el nido de la serpiente dentro de la cámara de crecimiento, sino que activamente usaron los huevos como estructuras de soporte para el crecimiento del hongo simbionte. La ausencia de agresión hacia la hembra ovipositora (presumiblemente) y hacia los neonatos emergentes, sugiere que ésta asociación puede representar más que una asociación de comensalismo y amerita estudios futuros

The objective of our study was to review and quantify the level of knowledge of the biology of tortoise and freshwater turtle species of Colombia based on studies conducted in the country. We used the resulting rankings in knowledge, in combination with IUCN threat category, presence in protected areas, and endemism, to propose conservation priorities. This process also allowed us to evaluate which aspects of turtle biology have been least studied. Four species obtained total values of zero or one over the 21 knowledge criteria employed, so they were ranked as the highest priority for research based on the lack of knowledge of their biology: Black-lined Toad-headed Turtle (Mesoclemmys raniceps), Amazon Toad-headed Turtle (Mesoclemmys heliostemma), Gibba Toad-headed Turtle (Mesoclemmys gibba), and Dunn’s Mud Turtle (Kinosternon dunni). Moreover, species in the family Chelidae in general were found to have limited levels of knowledge, which makes this group a priority for investigation. Evaluation of the di...

In August, investigators in Colombia were shocked by the Ministry of Environment and Sustainable Development's announcement that a new decree will impose a “compensatory” tax on persons involved in wildlife hunting ([ 1 ][1]). The tax is intended to generate revenues to help the Ministry manage

Intra-specific body size variation is common and often is assumed to be adaptive. Studies of body size variation among sites should include or consider environmental and ecological variables in their designs. Additionally, reciprocal transplant or common garden studies will support which variables are really contributing to the observed body size variation. This study analyzed the microgeographic body size variation in Anolis mariarum, a small lizard endemic to Antioquia, Colombia. Parameters such as body size, shape, and lepidosis variation were quantified in 217 adult A. mariarum, belonging to six populations separated by less than 80km. Results showed that significant body size variation was not related to differences among sites in mean annual temperature, but covaried with mean annual precipitation, with the largest individuals occurring in dryer sites. Mark-recapture data obtained from 115 individuals from both the wettest and dryest sites from October 2004 to April 2005 showed that growth rates were higher at the latter. Eight males from each site were captured at the end of the mark- recapture study and reared for two months under identical conditions in a common garden study. Individuals from both sites grew faster when reared in the laboratory with food provided ad libitum. Although growth rates of males from the two populations did not differ significantly in the laboratory, males from the dryest site still maintained a significantly larger asymptotic body size in their growth trajectories. Multivariate analyses also demonstrated that both males and females from the six populations differed in terms of body shape and lepidosis. However, only female body size was found to covary significantly with an environmental gradient (precipitation). A. mariarum does not conform to Bergmann’s rule, but the relationship found between mean body size and asympotic growth with mean annual precipitation at these sites needs further analysis. Generally, studies of intra-specific body size variation should consider a number of additional phenotypic traits to provide stronger baseline information on the degree of overall divergence among populations, including those likely to be selectively neutral, before interpreting results of analyses on the body size differences. Rev. Biol. Trop. 57 (4): 1253-1262. Epub 2009 December 01.Se reporta diferencias en el tamaño corporal entre individuos adultos de seis poblaciones de Anolis mariarum (Squamata: Polychrotidae), separadas por una distancia de hasta 80km. Esta variación no se relacionó con las diferencias en las temperaturas promedio anuales que existen entre los sitios analizados, pero sí covarió con la precipitación promedio anual, con los individuos de mayor talla habitando los sitios más secos. Datos de marca- recaptura del sitio más seco y más húmedo, mostraron que los individuos del sitio más seco tienen mayores tasas de crecimiento corporal. Bajo condiciones de laboratorio con alimento ad libitum, machos de ambos sitios crecieron más rápido que en condiciones naturales. Aunque las tasas de crecimiento de machos de las dos poblaciones no difirieron significativamente en el laboratorio, los machos del sitio más seco mantuvieron tamaños corporales asintóticos en sus trayectorias de crecimiento que fueron significativamente mayores. Análisis multivariados mostraron que tanto los machos como las hembras de las seis poblaciones difieren en la forma corporal y en lepiodosis, pero la única variable que covarió de manera significativa con un gradiente ambiental fue el tamaño corporal con la precipitación. Estudios de variación intraespecífica en el tamaño corporal deben considerar otras características fenotípicas adicionales para obtener una línea base sobre el grado de divergencia entre poblaciones, incluso aquellas que se consideran neutrales.

Lineage diversification in the Neotropics is an interesting topic in evolutionary biology but is also one of the least understood. The abiotic and biotic complexity of the region precludes generalizations that can be drawn regarding the historical evolutionary processes responsible for the diversity observed. The snake genus Leptodeira provides an excellent opportunity to investigate such processes because it spans the entire Neotropical region. In this study, we infer the phylogenetic position of Leptodeira within Dipsadinae, estimate evolutionary relationships among and within Leptodeira species, and estimate the diversification time and biogeography of the genus. Three mitochondrial gene regions were sequenced for individuals representing all the Leptodeira species and most subspecies currently recognized. Additionally, two nuclear protein-coding gene regions were sequenced for representatives of each species and several genera within the Dipsadinae. We infer that several Leptodeira species are either paraphyletic or polyphyletic as currently recognized, and that most recognized subspecies are not monophyletic lineages. Despite the taxonomic discordance with evolutionary relationships, clades appear to correspond very well to major biogeographic regions of Mexico, Central America and South America. Our results thus highlight the important role of the Miocene and Pliocene for lineage diversification in the Neotropics. Additionally, our time estimates suggest that recent intraspecific phylogeographic structure is likely the result of habitat and climatic fluctuations during the Pleistocene. Cumulatively, our inferences of lineage diversification within Leptodeira suggest a complex evolutionary scenario in the Mexican transition zone and a north to south expansion with a final colonization of the tropics in South America.

We studied the reproductive ecology of the slider turtle. Trachemys scripta callirostris, during the reproductive season of the year 2000, in an area of the Mompós Depression, northern Colombia. We examined the number of nests ovoposited in locations with different characteristics, their hatching success rates and the natural causes of egg mortality. We also determined the effects of exploitation of nesting females, in two populations with different levels of harvesting. The results showed that the majority of nests were laid along bodies of water, in the first 20 m of the shoreline, in sites with substrates of moderate humidity, sand and clayish texture, covered by creeping vegetation. Invertebrates produced the greatest mortality in the nests. Hatching success was high, compared to other reports for this species. Only in the site with the highest hunting pressure a negative correlation was found, between the harvest rate and the time elapsed since the start of the nesting period, suggesting that the excessive extraction decreased the number of nesting females. Also, the females from the highly exploited site were significantly smaller than those from the less exploited site. The females, neonates and nests of the entire area, exhibited sizes below that reported for other tropical populations of the genus. The continued hunting pressure in northern Colombia, appears to be a factor that has altered the structure and population dynamics of T. scripta callirostris.

We studied the demography and nesting ecology of two populations of Iguana iguana that face heavy exploitation and habitat modification in the Momposina Depression, Colombia. Lineal transect data was analyzed using the Fourier model to provide estimates of social group densities, which was found to differ both within and among populations (1.05-6.0 groups/ha). Mean group size and overall iguana density estimates varied between populations as well (1.5-13.7 iguanas/ha). The density estimates were far lower than those reported from more protected areas in Panama and Venezuela. Iguana densities were consistently higher in sites located along rivers (2.5 iguanas/group) than in sites along the margin of marshes, probably due to vegetational differences (1.5 iguanas/group). There was no correlation between density estimates and estimates of relative abundance (number of iguanas seen/hour/person) due to differing detectabilities of iguana groups among sites. The adult sex ratio (1:2.5 males:females) agreed well with other reports in the literature based upon observation of adult social groups, and probably results from the polygynous mating system in this species rather than a real demographic skew. Nesting in this population occurs from the end of January through March and hatching occurs between April and May. We monitored 34 nests, which suffered little vertebrate predation, perhaps due to the lack of a complete vertebrate fauna in this densely inhabited area, but nests suffered from inundation, cattle trampling, and infestation by phorid fly larvae. Clutch sizes in these populations were lower than all other published reports except for the iguana population on the highly xeric island of Curaçao, implying that adult females in our area are unusually small. We argue that this is more likely the result of the exploitation of these populations rather than an adaptive response to environmentally extreme conditions.