Revista Científica SAREM–SBMz
Biodiversity conservation of high-altitudinal wetlands of Andean regions is relevant because they are suppliers of several ecosystem services; even more if we consider the putative consequences of climatic and land-use changes projected for the near future. These environments, characterized by severely stressing climatic and edaphic conditions, house a unique biodiversity, large levels of endemism and constitute a refuge and reproductive area for several species. The Laguna Brava reserve includes a system of high-altitude (mainly above 3000 m a.s.l.) Andean lagoons, peat bogs, and streams mostly situated in environments characteristic of the Puna and Altos Andes ecoregions of the province of La Rioja, Argentina. Except for some bird species, most components of the biota of Laguna Brava are scarcely known. There are not exhaustive inventories of the small terrestrial mammals, and all we know regarding this group comes from occasional mentions of a few species registered in a few localities. Here we present the results from field surveys of small terrestrial mammals conducted in the reserve between 2021 and 2023. We registered seven species of small terrestrial mammals for the reserve: Abrothrix andina, Akodon spegazzinii, Ctenomys eileenae, Eligmodontia moreni, Neotomys ebriosus, Phyllotis vaccarum, and Thylamys pallidior. The new records represent the first mention of T. pallidior, A. spegazzinii, E. moreni, and N. ebriosus for this protected area, adding localities for taxa scarcely known for their geographic distribution and constituting notable geographic range extension. The alpha diversity pattern shows a decrease in small mammal diversity (species richness decreases and dominance increases) from lower (east) to higher (west) altitudinal places (from approximately 3000 to more than 4300 m a.s.l.). Although our work has improved the knowledge of small terrestrial mammals in the Laguna Brava area, we note that at least four other small terrestrial rodent species could be registered in this reserve in the following years, including Calomys lepidus, Abrocoma cinerea, Galea comes, and Spalacopus cyanus.
Pequeños mamíferos terrestres (Rodentia y Didelphimorphia) de la reserva Laguna Brava, un humedal de altura en la provincia de La Rioja, oeste de Argentina. La conservación de la biodiversidad de los humedales de altura de las regiones andinas es relevante porque estos son proveedores de numerosos servicios ecosistémicos; más aún si consideramos las posibles consecuencias del cambio climático y del uso del suelo que se proyectan para el futuro cercano. Estos ambientes, caracterizados por condiciones climáticas y edáficas severamente estresantes, albergan una biodiversidad única, altos niveles de endemismos, y constituyen refugio y área de reproducción para numerosas especies. La reserva Laguna Brava incluye un sistema de lagunas, vegas y ríos de gran altura (por encima de 3000 m s.n.m.), mayormente situados en ambientes característicos de las ecorregiones de la Puna y Altos Andes en la provincia de La Rioja, Argentina. Con la excepción de algunas especies de aves, la mayor parte de los componentes de la biota de la Laguna Brava es escasamente conocida. No existen inventarios exhaustivos de los pequeños mamíferos terrestres y todo lo que conocemos acerca de este grupo consiste en menciones ocasionales de unas pocas especies registradas en unas pocas localidades. Aquí presentamos los resultados de inventarios de campo de pequeños mamíferos terrestres llevados a cabo en la reserva entre 2021 y 2023. Registramos siete especies de pequeños mamíferos terrestres para la reserva: Abrothrix andina, Akodon spegazzinii, Ctenomys eileenae, Eligmodontia moreni, Neotomys ebriosus, Phyllotis vaccarum y Thylamys pallidior. Los nuevos registros representan la primera mención de T. pallidior, A. spegazzinii, E. moreni y N. ebriosus para esta área protegida, y se adicionan localidades para taxones escasamente conocidos en su distribución geográfica, lo que constituye extensiones geográficas notables. El patrón altitudinal de diversidad alfa muestra un decrecimiento de la diversidad (disminución de la riqueza e incremento de la dominancia) desde sitios de menor (situados al este) a mayor altitud (situados al oeste) (desde aproximadamente 3000 a más de 4300 m s.n.m.). Si bien nuestro trabajo ha mejorado el conocimiento de los pequeños mamíferos terrestres en el área de Laguna Brava, notamos que al menos otras cuatro especies de pequeños mamíferos terrestres podrían ser registradas en esta reserva en años venideros, incluyendo Calomys lepidus, Abrocoma cinerea, Galea comes y Spalacopus cyanus.
El Espinal es una de las ecorregiones más transformadas de Argentina. Pese a las presiones de cambio en el uso del suelo hacia actividades agrícolas intensivas, algunos productores integran la ganadería con el bosque nativo, generando una oportunidad para conciliar conservación con producción. Actualmente, la degradación de estos bosques suele definirse según las condiciones del forraje, sin considerar criterios ambientales más amplios. En este estudio comparamos la riqueza, tasa de encuentro (como proxy de intensidad de uso) y composición de especies del ensamble de mamíferos medianos y grandes, estimadas a partir de datos generados con cámaras trampa, entre sitios con < 15% de cobertura arbustiva («no degradado», en términos productivos, n = 18) y > 25% («degradado», en términos productivos, n = 18) en predios ganaderos del Espinal entrerriano. Asimismo, analizamos la relación entre la riqueza y la tasa de encuentro de mamíferos con la estructura vegetal, la proporción y cantidad de coberturas del suelo circundantes, la accesibilidad (como proxy de presión de caza), y la tasa de encuentro de ganado (como proxy de intensidad de uso del ganado). En total, registramos 10 especies nativas y dos introducidas. La riqueza total de especies de mamíferos fue similar entre sitios arbustizados y no arbustizados, pero los primeros albergaron más especies en promedio (2,8 ± 0,3 versus 1,6 ± 0,3). Además de la cobertura arbustiva, la tasa de encuentro de ganado y el número de coberturas de suelo circundantes también influyeron significativamente en la tasa de encuentro de mamíferos en cada sitio, y la distancia a localidades, en la tasa de encuentro de mamíferos con interés cinegético. Si bien los sitios arbustizados son menos favorables para la ganadería, contribuirían a mantener la biodiversidad nativa del Espinal entrerriano, y propiciar la compatibilidad entre conservación y producción.
Shrub encroachment and mammals in livestock farms of Entre Ríos’ Espinal: a difficult balance to achieve. The Espinal is one of Argentina’s most transformed ecoregions. Despite pressure to change land use towards intensive agricultural activities, some ranchers integrate livestock with the native forest, representing an opportunity to reconcile conservation with production. Currently, the degradation of these forests is usually defined by forage conditions without considering broader environmental criteria. In this study, we use camera traps to compare species richness, encounter rates (as a proxy of use intensity), and composition of the small- and medium-sized mammal assemblage between sites with < 15% shrub cover (“not degraded”, in ranching-productive terms, n = 18) and > 25% (“degraded”, in ranching-productive terms, n = 18) in properties with cattle ranching in the Espinal of Entre Ríos province. Additionally, we analyzed the relationship between mammal species richness and encounter rates with the vegetation structure, the proportion and quantity of surrounding land covers, accessibility (as a proxy for hunting pressure), and livestock encounter rate (as a proxy of livestock use intensity). In total, we registered 10 native and two introduced species. The total richness of mammal species was similar between shrubby and not-shrubby sites, but the shrubby sites hosted more species on average (2.8 ± 0.3 versus 1.6 ± 0.3). Besides the shrub coverage, the livestock encounter rate, and the number of surrounding land covers also significantly influenced the richness and encounter rate of mammals in each site. While the shrubby sites were less favorable for ranching, they are contributing to maintaining the native biodiversity of the Espinal in Entre Ríos, supporting the compatibility between conservation and production.
Con el objetivo de conocer la composición de los ensambles parasitarios de camélidos sudamericanos (CSA) prehispánicos en diversas localidades y períodos históricos de Patagonia, se examinaron coprolitos asignados provisoriamente a estos artiodáctilos. Los coprolitos fueron obtenidos desde la Cueva Milodón Norte 1 (CMN1), localizada en la provincia de Santa Cruz, Argentina. Las muestras analizadas corresponden a niveles asociados a tiempos históricos hasta los 5880 ± 100 años antes del presente (AP). El examen parasitológico corroboró la contemporaneidad del nivel 1 de CMN1 con la colonización europea. Se identificaron unos 12 taxa parasitarios (Trichuris sp. 1, Trichuris sp. 2, Eimeria macusaniensis, Eimeria lamae, Capillariinae gen. sp. 1, Capillariinae gen. sp. 2, Capillariinae gen. sp. 3, Trichosomoidinae gen. sp., Marshallagia sp., Molineidae gen. sp., Trichostrongylidae gen. y Anoplocephalidae gen. sp.), de los cuales siete se reportan por primera vez en el sitio CMN1. Asimismo, algunos de ellos representan primeros reportes en CSA prehispánicos. Trichosomoidinae gen. sp. y Capillariinae gen. sp. 3 son inéditos para los datos parasitológicos de CSA, aunque se requieren nuevos hallazgos para su corroboración taxonómica. La información parasitológica de CSA actuales considera un menor número de especies parasitarias autóctonas que el obtenido a partir de muestras prehispánicas, aunque reporta una mayor riqueza parasitaria actual debido, mayormente, a especies invasoras. El proceso de colonización europea y las concomitantes invasiones biológicas pudieron haber modificado las comunidades parasitarias de guanacos patagónicos.
Guanacos and parasites at the Milodon North Cave 1 archaeological site, Santa Cruz province, Argentina. To understand the composition of parasite assemblages of pre-Hispanic South American camelids (SAC) in diverse localities of Patagonia, coprolites tentatively assigned to SAC and obtained from a little-explored archaeological site, Cueva Milodón Norte 1 (CMN1), located in the province of Santa Cruz, Argentina, were analyzed. The samples analyzed correspond to levels associated with historical times up to 5880 ± 100 years before present (BP). The parasitological examination confirmed the contemporaneity of CMN1 level 1 with European colonization. Around 12 parasitic taxa were identified (Trichuris sp., Trichuris sp. 2, Eimeria macusaniensis, Eimeria lamae, Capillariinae gen. sp. 1, Capillariinae gen. sp. 2, Capillariinae gen. sp. 3, Trichosomoidinae gen. sp., Marshallagia sp., Molineidae gen. sp., Trichostrongylidae gen. and Anoplocephalidae gen. sp.), of which seven are reported for the first time at the CMN1 archaeological site. Likewise, some of them are first reports in pre-Hispanic SAC. Trichosomoidinae gen. sp. and Capillariinae gen. sp. 3 are unprecedented for SAC parasitology, although require new findings for corroboration. The current SAC parasitology considers a smaller number of native parasite species than that obtained in archaeological sites, although it reports a greater parasite richness, mainly constituted of invasive species. The European colonization process and the concomitant biological invasions could have modified the parasite communities of Patagonian guanacos.
Mesmo diante da ameaça à extinção, pouco se conhece sobre as populações de tamanduá-bandeira (Myrmecophaga tridactyla) na região Amazônica. São animais pouco avistados em florestas densas e, portanto, dados oriundos de armadilhas fotográficas são valiosos para estudos sobre a espécie. Desde 2016, a Reserva Biológica do Gurupi, Área de Endemismo Belém, é contemplada pelo Projeto Monitora do ICMBio que, através de armadilhas fotográficas, obtém uma ampla gama de informações de mamíferos de médio e grande porte na região. Através do modelo dinâmico desenvolvido por Dail & Madsen (2011), buscamos conhecer a tendência populacional do tamanduá-bandeira na unidade entre os anos de 2016 e 2022, estimando sua taxa de crescimento. Além disso, por meio de análise bayesiana, entender como a elevação, distância para rios, distância para borda de floresta e área basal influenciam a ocupação pela espécie na REBIO. Nota-se que há uma tendência ao declínio da população nos últimos anos de monitoramento, porém a taxa de crescimento não foi significativamente diferente de zero. Entre as variáveis preditoras para ocupação, somente a elevação demonstrou afetar as taxas de ocupação pela espécie, com a preferência por áreas de menores elevações, possivelmente devido a uma maior abundância de recursos. Assim, este manuscrito demonstra a importância da continuidade do monitoramento nas unidades de conservação, principalmente por permitir que um possível declínio populacional seja detectado rapidamente, favorecendo intervenções e estudos para conservação.
Population trends of the giant anteater (Myrmecophaga tridactyla, Linnaeus 1758), in the Gurupi Biological Reserve. Despite the looming threat of extinction, limited information is available regarding the populations of the giant anteater (Myrmecophaga tridactyla) in the Amazon region. These animals are rarely observed in dense forests, making data from camera traps invaluable for studying the species. Since 2016, the Gurupi Biological Reserve, an area of Belém endemism, has been monitored through the ICMBio Monitor Project, which utilizes camera traps to collect extensive data on medium and large mammals in the region. Using the dynamic model developed by Dail & Madsen (2011), we aimed to assess the population trend of the giant anteater in this reserve between 2016 and 2022, estimating the growth rate. Additionally, through Bayesian analysis, we investigated how factors such as elevation, distance to rivers, distance to the forest edge, and basal area influence species occupancy within the reserve. The results indicate a trend toward population decline in recent years of monitoring, although the growth rate was not significantly different from zero. Among the variations of predictors for occupancy, only elevation showed a significant rate, with a preference for areas of lower elevation, potentially due to the greater abundance of resources in these areas. This study highlights the critical role of ongoing monitoring in conservation units, particularly to detect potential population declines early and support conservation interventions and further research.
O uso de marcos dentários para a estimação da idade é comum em estudos de diversos taxa. Em especial, o processo de formação e substituição dos dentes molariformes, com cronologia geneticamente determinada, é frequentemente utilizado em técnicas de identificação da idade em mamíferos. No presente trabalho, foram realizadas análises radiográficas para investigar a cronologia mensal de eventos dentários, tais como o surgimento de cistos formadores de dentes, mineralização de coroa e raiz, eclosão e troca dentária em Subulo gouazoubira e Mazama rufa. Os indivíduos foram radiografados sob anestesia geral e os achados radiológicos foram organizados do primeiro ao vigésimo quinto mês de vida. Uma vez definidos os eventos dentários mensais, esses resultados foram comparados com quatro S. gouazoubira vivos e 31 preparações osteológicas de cabeças (25 S. gouazoubira, três M. rufa, dois M. nana e um M. jucunda). Vinte e dois animais foram identificados como tendo idades entre um a 24 meses, enquanto outros 13 tinham 25 meses ou mais. Todos os eventos dentários listados estavam presentes nas determinações de idade realizadas, evidenciando a acurácia mensal da técnica.
Dental development in Subulo gouazoubira and Mazama rufa (Arctiodactyla: Cervidae), and its application for age determination in deers. The use of dentition and dental traits for age determination is common in studies of several taxa. In particular, the genetically determined process of forming and replacing molariform teeth is frequently used for age determination in mammals. In the present study, radiographic analyses were conducted to investigate the monthly chronology of dental development, such as the appearance of tooth-forming cysts, crown and root mineralization, tooth eruption, and tooth exchange in Subulo gouazoubira and Mazama rufa. Subjects were anesthetized and radiographed, and radiological findings were organized from the first to the twenty-fifth month of age. Once the monthly stages were defined, these data were compared with four S. gouazoubira alive and 31 osteological preparations of heads (25 S. gouazoubira, three M. rufa, two M. nana, and one M. jucunda). Of these examinations, 22 were identified as having between one and 24 months of age, and the other 13 were 25 months old or older. All stages listed were observed in the age determinations performed, confirming the monthly accuracy of the technique.
El estudio de murciélagos es complejo porque son animales nocturnos y voladores. Para registrar las especies que habitan en un sitio se recomienda el uso combinado de métodos. Sin embargo, para los estudios de impacto ambiental en Chile, la autoridad recomienda la captura de murciélagos mediante red de niebla. En este estudio comparamos efectividad y eficiencia de dos métodos de evaluación de murciélagos: el registro acústico y la captura mediante el uso de trampas (red de niebla y trampa arpa). Durante la temporada estival de 2013–2014 se evaluó mensualmente la riqueza y abundancia relativa de murciélagos con estos métodos en remanentes de bosque esclerófilo en Chile central. El registro acústico detectó el 100% de las especies potencialmente presentes en el área de estudio (n = 6) y registró la presencia de murciélagos en todos los sitios de muestreo (n = 12). La captura de individuos detectó solo el 33% de las especies potenciales y registró presencia de murciélagos en la mitad de los sitios. Al comparar la eficiencia de los métodos, el registro acústico presentó un menor costo en función del número de especies detectadas, donde la captura resultó un 159% más costosa. Debido a la mayor eficacia y eficiencia del registro acústico respecto de la captura, junto con sus características no invasivas y respetuosas con la fauna que evitan el estrés y daño potencial a los individuos, se recomienda considerar el registro acústico como el principal método de muestreo para registrar las especies de murciélagos en la evaluación ambiental de proyectos de desarrollo en Chile central.
Comparison of the effectiveness and efficiency of acoustic survey and capture to evaluate bats in Mediterranean temperate forests of central Chile. The study of bats is complex because they are nocturnal flying animals. To record the species that inhabit a site, the international literature generally recommends the combined use of methods. However, in Chile, the environmental authority suggests capturing individuals using mist nets for the evaluation of bats in environmental impact studies. In this study, we compared the effectiveness and efficiency of two methods used for bat assessment: acoustic recording and capture. During the 2013–14 summer season, we evaluated monthly the richness and relative abundance of bats with these methods in remnants of sclerophyllous forest in central Chile. The acoustic record detected 100% of the species potentially present in the study area (n = 6) and recorded the presence of bats at all sampling sites (n = 12). Captures detected only 33% of the potential species and recorded the presence of bats in half of the sampling sites. When comparing the efficiency of the methods, the acoustic recording presented a lower cost based on the number of species detected, where the capture was 159% more expensive. Given the superior effectiveness and efficiency of acoustic recording relative to capture methods, coupled with its non-invasive and wildlife-friendly characteristics that eliminate stress and potential harm to individuals, it is recommended that acoustic recording be considered the primary sampling method to record bats in the environmental evaluation of development projects in central Chile.
The continuous habitat degradation and fragmentation are increasing the movement of black and gold howler monkeys (Alouatta caraya) towards urbanized areas in northeast Argentina, looking for shelter and food. Alouatta caraya is categorized as “Vulnerable” in Argentina and usually tolerates moderate levels of habitat modification. Our objective was to use community science as a tool to characterize the distribution and size of A. caraya groups living in urban areas of Corrientes, Argentina, assess their current and potential threats, involve society in the data collection, and participate in the conservation of the species. We carried out semi-structured surveys from March to June 2023 using the Survey 123 application (ArcGIS; ESRI 2011), disseminating them through social networks, local newspapers, and radio news. We obtained 63 responses containing information on geographical location across 19 neighborhoods, howler monkey group size (mean of 5.88 individuals, SD ± 4.14), and the presence of females carrying an infant in 55.5% of sightings. Interactions with the human population and domestic animals were reported in 67% of cases; daily activities such as feeding, resting, howling, and moving were observed on different types of substrates. While 12% of respondents believed that howlers are not exposed to danger, 8.5% considered them to be critically endangered when living in the neighborhood. This is the first study in the city of Corrientes that allows us to understand the effects of the continued unregulated urbanization, the presence and distribution patterns of A. caraya, the use of anthropogenic elements, the specific hazard identification, and the people’s attitudes towards them.
«Aullando por la Ciudad»: un proyecto de ciencia comunitaria para identificar monos aulladores y sus amenazas en el noreste de Argentina. La continua degradación y fragmentación del hábitat en el noreste de Argentina han llevado a los monos aulladores negros y dorados (Alouatta caraya) a desplazarse hacia áreas urbanizadas en busca de refugio y alimento. Alouatta caraya está categorizada como “Vulnerable” en Argentina y se caracteriza por tolerar niveles moderados de modificación del hábitat. El objetivo de este trabajo fue hacer uso de la ciencia comunitaria como herramienta para caracterizar la distribución y el tamaño de grupos de A. caraya en ambientes urbanos y periurbanos de Corrientes, Argentina, y evaluar las amenazas actuales y potenciales, involucrando a la sociedad en la colecta de datos y conservación de la especie. Entre marzo y junio de 2023 realizamos encuestas semiestructuradas utilizando la aplicación Survey 123 (ArcGIS; ESRI 2011), difundidas en redes sociales, periódicos y radio. Recibimos 63 respuestas con información sobre la geolocalización en 19 barrios, con un tamaño de grupo de 5,88 individuos, SD ± 4,14 y con un 55,5% de avistamientos de hembras con cría. Se registraron interacciones con humanos y animales domésticos en el 67% de los casos. Las principales actividades observadas fueron alimentación, descanso, aullidos y desplazamientos sobre diferentes tipos de substratos. Mientras que el 12% de las personas creían que los aulladores no estaban expuestos a peligros, el 8,5% los consideró en peligro crítico por el hecho de vivir en barrios. Este es el primer estudio en Corrientes que permitió analizar los efectos de la urbanización en A. caraya, su distribución, el uso de elementos antropogénicos, los riesgos específicos y el comportamiento de la comunidad hacia ellos.
