Living near water: Ecological observations on the Ecuador Sipo, Chironius grandisquamis, (Peters 1869) (Serpentes: Colubridae), in the Middle Magdalena River Valley, Colombia

More than 40 species of snakes inhabit the humid forests of the Middle Magdalena River Basin of Colombia, yet studies on the basic aspects of snake ecology and natural history in this region are scarce. We searched for Ecuador Sipos (Chironius grandisquamis) during six years (2014–2019) of 6–24-day visual-encounter surveys by day and night in both rainy and dry periods. In 2,967 person-hours, we recorded 16 individuals, half during rainy and half during dry periods. Fourteen of the 16 encounters were in the evening and two in the morning. Snakes recorded during the day were foraging on the ground, whereas those recorded at night were inactive and perched in vegetation. Most inactive individuals had selected perches along streams flanked by riparian forests; ten were in shrubs and four in trees on branches 120–600 cm above the ground. We also record predation on a northern rainfrog (Craugastor metriosistus) on the forest floor during the day.

Evaluation and space representation of the maximum surface runoff in watersheds

In Cuba, regardless of the advances made in hydrological and hydraulic investigations related to floods, there are limitations with the detailed knowledge of the true maximum surface runoff or maximum flow that characterizes these phenomena in the season of intense rains, for which it is necessary to carry out complex hydrological study that, with the help of professional software and statistical techniques, help to determine and model spatially with certain reliability, the maximum water surface drained in watersheds. The general objective was pursued: To determine and represent spatially with the use of Geographic Information Systems (GIS) and hydrological methods, the runoff or maximum flow produced by the intense rains in a watershed, selecting to exemplify the watershed from the Magdalena River to the south east of the Santiago de Cuba municipality. As a result was obtained in the first instance, that it is feasible to apply this procedure to know in a preliminary way what maximum flow is available at any point of a main river or tributary. This approximation constitutes a significant advance for subsequent work in other watersheds of Cuba or internationally.

Mitochondrial Genetic Diversity, Population Structure and Detection of Antillean and Amazonian Manatees in Colombia: New Areas and New Techniques

The Antillean manatee (Trichechus manatus) and the Amazonian manatee (Trichechus inunguis) are distributed in rivers in the Caribbean and Amazonian region of Colombia respectively. For 30 years, genetic information has been obtained from these populations in order to inform conservation programs for these endangered species and decide on the location to release them back to the wild. However, in previous studies, samples from rivers in some areas of the country were not included, given the difficulties to access these regions due to either logistic or safety issues. In this study, we analyzed mitochondrial DNA (mtDNA) control region (CR) sequences of from samples of T. manatus (n = 37) and T. inunguis (n = 4) (410 and 361 bp, respectively), obtained in new and previously unexplored rivers and bays in the country, including Santa Marta, Urabá Gulf, Ayapel Marsh (San Jorge River Basin), Meta River and Magdalena Medio and the low Magdalena River (Cesar Province and Canal del Dique) as well as additional samples from Puerto Nariño in the Colombian Amazon. Our results included the discovery of two newly described mtDNA CR haplotypes for T. manatus. In addition, we confirmed significant population differentiation at the mitochondrial level between the Magdalena and Sinú rivers and differentiation among areas of the same river, including the middle and low Magdalena River. This differentiation may be related to anthropic changes in the river since construction of the Canal del Dique in the XVI century. We also tested environmental DNA sampling and analyses techniques to evaluate its potential use for manatee detection and monitoring in bodies of water in Colombia, in order to evaluate new areas for future manatee conservation initiatives. We emphasize the need to continue using genetic information to provide evidence on the potential best locations to undertake animal release to prevent outbreeding depression.

Spatio-Temporal Variability of Hydroclimatology in the Upper Cauca River Basin in Southwestern Colombia: Pre- and Post-Salvajina Dam Perspective

The Cauca River rises in the Colombian Andes and is the main tributary of the Magdalena River, which drains to the Caribbean Sea. The La Balsa station monitors the Upper Cauca basin and is located just downstream of La Salvajina hydroelectric facility. At this station, the discharge time series for November–January during 1950–2019 shows a statistically significant downward break, and change of distribution after 1986 has been documented after La Salvajina started operation. We assessed the spatio-temporal variability of hydroclimatology in the upper Cauca River basin during the pre- and post-Salvajina dam periods to better understand this break. Post-Salvajina, low (high) discharge events are linked to negative (positive) precipitation and soil moisture anomalies that are greater in magnitude and extension than those recorded in the pre-Salvajina period in response to the more intense El Niño events (more intense and frequent central La Niña events) after 1986. Therefore, it is necessary to consider possible future rainfall scenarios and non-infrastructure measures (i.e., reforestation, territorial planning, integrated watershed management, etc.) to mitigate floods and droughts impacts. The contribution of this study is to provide evidence for the need for foresight in the design of any structural or non-structural flood measures.

Criterios de uso y conservación de árboles en potreros basados en el conocimiento local de los ganaderos en una zona de bosque seco tropical en Colombia

Trees are attributed an important role in livestock farms, fulfilling various functions. The study documents the retention of woody species in cattle farms from local and technical knowledge in the upper part of the Magdalena river basin, Colombia. 195 semi-structured questionnaires were applied to identify the perception of producers about the classification and uses of tree forage species, based on physical, nutritional, phenological and environmental criteria, as indicators of conservation and use of species in pastures. With these indicators, indices were constructed that identified important characteristics of the species mentioned by the ranchers. Data were analyzed with descriptive statistics, mean comparisons, and multivariate analysis techniques. It is recognized that producers appreciate species based on criteria of use and functions related to their productive activity. Six highly valued species Gliricidia sepium, Guazuma ulmifolia, Pithecellobium dulce, Albizia guachapele, Acacia farnesiana and Albizia saman coincide with other studies of local knowledge. The study provides relevant information on twelve species associated with livestock, which have not been reported in previous studies, so it suggests deepening and complementing with scientific knowledge to recognize and assess the use of these potential species for livestock production, allowing interaction between knowledge in a concerted technological system.