ABSTRACT
Microplastics (MPs) are found in a wide range of ecosystems, from the Arctic to the deep ocean. However, there is no data on their presence in terrestrial mammals that inhabit the Selva Maya. The aim of this study is to detect the presence of MPs in the feces of the Baird's tapir (Tapirus bairdii) from the region of Calakmul, located in the Yucatan Peninsula, Mexico. We analyzed 129 fecal samples collected during 2017 and 2018, obtaining 57 and 72 samples during the rainy and dry seasons respectively. Sixty-eight percent of the samples contained 743 MPs with a mean of 19.3 ± 28.1 MPs/kg of dry weight (DW) feces in both years. An inter-annual variation in the average abundance of microplastic was observed during the two-year period (2017-2018), with a 72 % increase in these plastic particles in feces. Fourteen polymers were identified, with ethylene vinyl acetate (EVA), polypropylene (PP) and polyester (PES) being the most abundant during both years. Although the effects of MPs on the health of tapirs are not known, their presence is cause for concern. There is an urgent need for the implementation of appropriate plastic waste management programs in communities of the Selva Maya to diminish the consumption of MPs in species including humans where they pose a significant risk to health. ENVIRONMENTAL IMPLICATIONS: The use of plastics worldwide is increasing every day, so the presence of microplastics is and will continue to be a major environmental problem. It is known that contaminants can adhere to plastics, making them hazardous materials. Microplastics can contaminate remote areas such as Biosphere Reserves. Terrestrial species such as the tapir can ingest microplastics, putting their health at risk. Knowing the dispersion of microplastics is very important in order to manage them properly, taking into account their emission sources and type of polymer.
Subject(s)
Environmental Monitoring , Feces , Microplastics , Perissodactyla , Animals , Microplastics/analysis , Feces/chemistry , Mexico , Water Pollutants, Chemical/analysis , Plastics/analysis , SeasonsABSTRACT
Introducción: La selección de refugios diurnos es un proceso crucial para los murciélagos debido a su influencia en la ecología, organización social y supervivencia de sus poblaciones. El murciélago narigón (Rhynchonycteris naso) es una especie protegida por leyes de México, cuyos refugios y zonas de forrajeo, están estrictamente asociados a cuerpos de agua, principalmente ríos. Por lo tanto, cambios en la calidad del agua suponen un riesgo para sus poblaciones. Sin embargo, el conocimiento sobre el estado actual de sus poblaciones y refugios diurnos en México, es escaso. Objetivo: Ubicar y describir los refugios diurnos de R. naso y evaluar la relación del tamaño del grupo de murciélagos con las características de los refugios, la salinidad y el pH del agua donde habitan. Métodos: De marzo a octubre 2015, se realizaron búsquedas de refugios diurnos mediante recorridos en lancha a lo largo de ríos, arroyos y lagunas, en once sitios del Área de Protección de Flora y Fauna Laguna de Términos, Campeche México. Por cada refugio localizado se registró el tamaño del grupo y su acomodo en el refugio, el tipo de refugio, el tipo de vegetación, la cobertura, la distancia entre refugios, el diámetro del tronco, la salinidad y el pH. Para investigar el efecto de las variables registradas en los refugios sobre el tamaño de cada grupo, se ajustaron Modelos Lineales Generalizados. Resultados: Encontramos 48 refugios en troncos secos, cortezas de árboles y puentes, asociados a cuerpos de agua dulce y oligohalina, principalmente en vegetación de manglar. El promedio (± EE) del tamaño del grupo fue de 5.3 ± 0.48 para los refugios naturales y de 22.6 ± 9.54 para los artificiales. Encontramos una relación significativa con el tipo de refugio, el tipo de vegetación y el diámetro del tronco. Los refugios con tamaño de grupo mayores presentaron un acomodo agregado. Se localizaron 40 refugios sobre cuerpos de agua dulce y ocho en oligohalina con alto nivel de agrupamiento. Conclusiones: La mayor incidencia de refugios en sitios de agua dulce y ligeramente ácida, es explicada bajo la teoría del óptimo forrajeo. Debido a que el área de estudio se encuentra en el límite de su distribución, el manglar representa el tipo de vegetación más importante para garantizar la permanencia de las poblaciones de R. naso. Adicionalmente, debido a que en algunas porciones de la zona de estudio no fue posible encontrar refugios, es crucial llevar a cabo estudios sobre la calidad del agua y los niveles de contaminación en la región. Este estudio proporciona información relevante sobre las poblaciones del murciélago Rhynchonycteris naso con implicaciones directas sobre su conservación en zonas ribereñas y humedales costeros.
Introduction: The selection of day-roost is a crucial process for bats because it influences the ecology, social organization, and survivorship aspects of their populations. Proboscis bat (Rhynchonycteris naso) is a protected species by Mexican law, whose foraging and roosting areas are strongly associated with bodies of water, primarily rivers. Therefore, alterations in the water quality pose a risk to their populations. However, knowledge of the current state of their populations and roosting ecology is very poor in Mexico. Objectives: To locate and to describe R. naso's diurnal roosts, and to evaluate the relationship of the group size per roost with the characteristics of the diurnal roost, the salinity and pH of the water where they inhabit. Methods: From March to October 2015, we searched diurnal roost through boat tours along rivers, streams, and lagoons, in eleven sites in the Laguna de Términos Flora and Fauna Protection Area, Campeche, Mexico. For each localized roost, we recorded the group size, and their spatial distribution, the type of roost and vegetation, the distance between roosts, the diameter of trunk, the salinity, and pH. In order to investigate the effect of the variables recorded in diurnal roost on size group, generalized linear models were adjusted. Results: We found 48 diurnal roost in dead tree-trunks, tree bark and bridges, associated with freshwater, and oligohaline bodies, mainly in mangrove vegetation. The average size of the groups was 5.3 ± 0.48 and 22.6 ± 9.54 in natural and artificial roosts, respectively. We found a significant relationship with the type of roost, type of vegetation and diameter of trunk. Roosts with larger groups of bats presented an aggregated distribution. We located 40 diurnal roosts on freshwater bodies and eight in oligohaline with a high grouping level. Conclusions: Greater incidence of roost in fresh and lightly acid water is explained under optimal foraging theory. Because the study area is found in the limit of their distribution, mangrove is a very important vegetation type to guarantee the establishment of R. naso populations. Also, due no roosts were found in some portions of the study zone, quality of water, and contaminant level studies are crucial. This study provides relevant information on their populations with direct implications for the conservation in coastal areas.
Subject(s)
Animals , Chiroptera/anatomy & histology , Refugium , MexicoABSTRACT
Bat acoustic libraries are important tools that assemble echolocation calls to allow the comparison and discrimination to confirm species identifications. The Sonozotz project represents the first nation-wide library of bat echolocation calls for a megadiverse country. It was assembled following a standardized recording protocol that aimed to cover different recording habitats, recording techniques, and call variation inherent to individuals. The Sonozotz project included 69 species of echolocating bats, a high species richness that represents 50% of bat species found in the country. We include recommendations on how the database can be used and how the sampling methods can be potentially replicated in countries with similar environmental and geographic conditions. To our knowledge, this represents the most exhaustive effort to date to document and compile the diversity of bat echolocation calls for a megadiverse country. This database will be useful to address a range of ecological questions including the effects of anthropogenic activities on bat communities through the analysis of bat sound.
