Patrones de actividad diaria y lunar de Cavia tschudii (Rodentia) en un humedal costero tropical

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Cavia tschudii es un roedor silvestre que habita pastizales y humedales andinos y costeros, cuyos aspectos ecológicos han sido poco estudiados. En este estudio describimos sus patrones de actividad diaria y evaluamos el efecto de la luminosidad lunar sobre su actividad nocturna durante las temporadas húmeda de 2019 y seca de 2020 en un área de juncales de un humedal costero de Perú. Además, evaluamos el solapamiento de actividad de C. tschudii con las especies que co-ocurrieron con él. Utilizando seis estaciones de cámaras trampa y analizando las fechas y horas de registros encontramos que durante ambas temporadas C. tschudii fue mayormente nocturno, los perros, catemerales y Rattus sp., nocturno. La actividad de C. tschudii tuvo un solapamiento moderado con los perros y alto con Rattus sp. Durante ambas temporadas C. tschudii mostró dos picos de actividad cuando la luminosidad lunar era de 76–100% y 1–25%. Asimismo, en la estación seca su actividad nocturna tuvo correlación positiva con la luminosidad lunar. Este es el primer estudio que en condiciones naturales evalúa los patrones de actividad diaria y lunar de C. tschudii. Concluimos que la actividad diaria de C. tschudii es mayormente nocturna durante ambas temporadas, pero durante la temporada seca la actividad nocturna se incrementa; el mayor solapamiento de actividad con Rattus sp. sugiere una posible competencia; y la actividad nocturna de C. tschudii durante la temporada seca sugiere que aprovecha la luz de la luna para mejorar su búsqueda de alimento y detección de depredadores.


Daily and moon activity patterns of Cavia tschudii (Rodentia) in a tropical coastal wetland. Cavia tschudii is a wild rodent that inhabits Andean and coastal grasslands and wetlands, whose ecological aspects have been rarely studied. In this study we describe their daily activity patterns and evaluate the effect of lunar luminosity on their nocturnal activity during the 2019 wet and 2020 dry seasons in a bulrush community of a coastal wetland in Peru. Moreover, we evaluated the activity overlap of C. tschudii with the species that co-occurred with it. Using six camera trap stations and analyzing the dates and times of the recordings, we found that during both seasons C. tschudii was mainly nocturnal, the dogs were cathemeral and Rattus sp. was nocturnal. The activity of C. tschudii had a moderate overlap with the dogs and a high overlap with Rattus sp. During both seasons C. tschudii showed two peaks of activity when the lunar luminosity was 76–100% and 1–25%. Likewise, in the dry season, its nocturnal activity had a positive correlation with lunar luminosity. This is the first study that evaluates the daily and lunar activity patterns of C. tschudii under natural conditions. We conclude that the daily activity of C. tschudii is mostly nocturnal during both seasons, but during the dry season the nocturnal activity increases; the highest activity overlap with Rattus sp. suggests a possible competition; and the nocturnal activity of C. tschudii during the dry season suggests that it takes advantage of moonlight to improve its foraging and predator detection.

Distribución actualizada de Pteronotus (Phyllodia) (Chiroptera: Mormoopidae) en Venezuela, con el primer registro de Pteronotus (P.) alitonus

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Se actualiza la información disponible sobre la distribución geográfica de Pteronotus (Phyllodia) (Chiroptera: Mormoopidae) en Venezuela, como resultado del análisis taxonómico de ejemplares de museo y el diagnóstico de registros acústicos. Previo a este trabajo, tres especies del subgénero eran conocidas en territorio venezolano: Pteronotus (Phyllodia) paraguanensis, endémica de la península de Paraguaná; P. (Phyllodia) fuscus, con una distribución amplia que abarca la región norte (excepto Paraguaná), así como la porción septentrional de la Amazonía y el Escudo de Guayana; y P. (Phyllodia) rubiginosus, restringida al sur del río Orinoco. Una cuarta especie, P. (Phyllodia) alitonus, es señalada aquí por primera vez para el país, sobre la base de registros obtenidos en los estados Amazonas y Bolívar. Se describen los caracteres morfológicos que permiten separar a los miembros de Pteronotus (Phyllodia) que habitan el territorio venezolano, así como sus patrones de ecolocación. El hallazgo de P. (Phyllodia) alitonus incrementa a 405 el número de mamíferos conocidos en Venezuela (173 pertenecientes a Chiroptera) y extiende el rango de distribución de la especie aproximadamente 700 km al noroeste de la localidad más cercana previamente reportada.


Distributional status of Pteronotus (Phyllodia) (Chiroptera: Mormoopidae) in Venezuela, with the first record of Pteronotus (P.) alitonus. The information available on the geographical distribution of bats of Pteronotus (Phyllodia) (Chiroptera: Mormoopidae) in Venezuela is updated, as a result of the taxonomic analysis of museum specimens and the diagnosis of acoustic records. Prior to this work, three species of the subgenus were known in the Venezuelan territory: Pteronotus (Phyllodia) paraguanensis, endemic to the Paraguaná Peninsula; P. (Phyllodia) fuscus, with a wide distribution that covers the northern region (except Paraguaná), as well as the northern portion of the Amazon and the Guiana Shield; and P. (Phyllodia) rubiginosus, restricted to the south of the Orinoco River. A fourth species, P. (Phyllodia) alitonus, is included in the country for the first time, based on records obtained in the states of Amazonas and Bolívar. The morphological characters that allow identification of the species of Pteronotus (Phyllodia) that occur in Venezuela, as well as their echolocation patterns, are presented. The discovery of P. (P.) alitonus increases the number of known mammals in Venezuela to 405 (173 belonging to Chiroptera) and extends the distribution range of the species approximately 700 km northwest of the closest previously reported locality.

Armadillo (Dasypus spp.) density through use of camera trapping and burrow density in French Guiana

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Armadillo density estimates are important for species knowledge, but they are unknown in the Guiana Shield. We aimed at estimating Dasypus density through burrow density and camera trapping. We surveyed and trapped burrows in three protected sites in French Guiana, on strip transects covering 4.8 ha in each site, and estimated Dasypus density taking into account burrow measures and occupancy. Population densities ranged between 7.6 and 48.6 animals/km² for Dasypus sp. nov. and 10.3 and 34.7 animals/km² for D. kappleri. Dasypus density estimates through burrow survey and exclusive burrow entrance camera trapping is relatively low-cost, non-invasive and reliable.


Densidad de los armadillos (Dasypus spp.) mediante el uso de cámaras trampa y densidad de madrigueras en la Guayana Francesa. La densidad de armadillos
es desconocida en el Escudo guayanés. Nuestro objetivo fue estimar la densidad de Dasypus a través de la densidad de madrigueras y mediante cámaras trampa. Identificamos y monitoreamos madrigueras en tres sitios en Guayana Francesa, en transectos cubriendo 4.8 ha por sitio. Estimamos la densidad poblacional de Dasypus teniendo en cuenta las medidas y la ocupación de las madrigueras. Las densidades poblacionales variaron entre 7.6 y 48.6 animales/km² para Dasypus sp. nov. y 10.3 y 34.7 animales/km² para D. kappleri. Estimar la densidad de Dasypus mediante las madrigueras y cámaras trampas es relativamente de bajo costo, no invasivo y confiable.

Categorización de los mamíferos de Argentina 2019: resumen y análisis de las amenazas

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La evaluación de especies según su riesgo de extinción se ha convertido en una importante herramienta de decisión para la implementación de políticas de conservación. En este trabajo resumimos los resultados de la última categorización oficial de los mamíferos de Argentina, haciendo énfasis en las amenazas identificadas. Este proceso fue encabezado por la Dirección de Fauna Silvestre del Ministerio de Ambiente y Desarrollo Sostenible y la Sociedad Argentina para el Estudio de los Mamíferos, que a partir de distintos talleres y la participación de 446 especialistas generó la categorización de los mamíferos de Argentina 2019. Se siguió la metodología propuesta por la UICN con modificaciones para las evaluaciones regionales y se evaluaron 17 posibles amenazas. El principal resultado es una ficha para cada especie, publicada en línea y de acceso libre (https://cma.sarem.org.ar/). Se trabajó con 417 especies de mamíferos nativas, 16 de las cuales se consideró que no forman parte de la mastofauna argentina, y una especie no fue evaluada (Tremarctos ornatus) debido a controversias con respecto a su presencia en territorio argentino. Asimismo, se reconoció la presencia de poblaciones de 21 especies de mamíferos exóticos. El 24.8% de las especies de mamíferos de Argentina están amenazadas. El 92.7% de las especies de mamíferos están enfrentando alguna amenaza. Las amenazas que más afectan a los mamíferos de Argentina son la pérdida y degradación del hábitat, las cuales alcanzan al 80% de las especies. Este proceso es una herramienta vital para el manejo y la conservación de los mamíferos de Argentina.


Red List assessment of the mammals of Argentina 2019: summary and analysis of threats. Assessing the extinction risk of species has become an important decision tool for the implementation of species conservation policies. In this work we summarize the result of the latest official categorization of the mammals of Argentina with emphasis on the threats identified. The assessment process was led by the Wildlife Department of Argentina’s Ministry of Environment and Sustainable Development and the Argentinean Society for Mammal Research, which conducted the 2019 categorization of the mammals of Argentina during different workshops and with the participation of 446 specialists. The methodology for regional assessments proposed by the IUCN was followed, and 17 potential threats were evaluated. The main result is an on-line free access assessment for each species (https://cma.sarem.org.ar/). A total of 417 species were considered, 16 of which were deemed not to be part of the Argentine mammal fauna, and one was not assessed (Tremarctos ornatus) due to controversies regarding its presence in Argentina. Furthermore, the presence of 21 species of exotic mammals was recognized. A 24.8% of Argentina’s mammal species are threatened with extinction, and 92.7% of them are facing some kind of threat. The threats that affect the mammals of Argentina are habitat loss and degradation, which affect 80% of all assessed species. This process is a vital tool for the management and conservation of the mammals of Argentina.

Thermal imaging aids behavioural studies: the case of a diurnal Neotropical primate

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Emergence of new technology has broadened our understanding of species behaviour, even those that are common and well studied. We report the use of a thermal camera (TC) on a diurnal Neotropical primate, the brown howler monkey (Alouatta guariba). We describe the undocumented nocturnal activity, and present other contributions of the TC for the routine activities applied in the field. We were able to quickly locate groups and observe rare behaviours, such as interspecific interactions and the process of immigration. The TC allowed the location of fresh stool on the ground, ideal for non-invasive hormone measurements and seed dispersal studies. This device can be used to address many questions, particularly those combining behaviour and hormonal measurements, but may be unhelpful for surveys. We endorse its employment as it can be an invaluable tool for studying the behaviour of Neotropical primate species, even diurnal ones.


Sensor térmico auxilia estudos comportamentais: o caso de um primata diurno neotropical. O surgimento de novas tecnologias ampliou nossa compreensão do comportamento das espécies, mesmo aquelas que são comuns e bem estudadas. Relatamos o uso de um sensor térmico em um primata neotropical diurno, o bugio-ruivo (Alouatta guariba). Descrevemos sua atividade noturna não documentada e apresentamos outras contribuições do sensor térmico (ST) para as rotinas de campo. Conseguimos localizar grupos rapidamente e observar comportamentos raros, como interações interespecíficas e documentar o processo de imigração de indivíduos. O ST também permitiu a localização de fezes frescas no solo, ideal para estudos hormonais não-invasivos e sobre dispersão de sementes. Este dispositivo pode ser empregado para responder muitas questões, particularmente aquelas que combinam dados comportamentais e mensurações hormonais, mas pode não ser útil para levantamento/censo. Apoiamos sua utilização, pois pode ser uma ferramenta inestimável para estudar o comportamento de espécies de primatas neotropicais, mesmo os diurnos, e preencher lacunas de conhecimento.

Distribution patterns of Risso’s Dolphin, Grampus griseus, in offshore waters of Southeast Brazil assessed by aerial surveys

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The Risso’s dolphin, Grampus griseus, is widely distributed in temperate and tropical ocean waters around the world. Despite the known occurrence along the Brazilian coast, information regarding the spatial distribution of the species is scarce. Here we evaluated the distribution pattern of Risso’s dolphins using records obtained through 200 h of dedicated aerial surveys for marine mammals off the slope and outer continental shelf of Southeast Brazil, conducted between March and May 2012. A total of 16 groups of Risso’s dolphins was recorded with a median group size of 35 individuals (range = 1–300). Environmental variables (i.e., depth, slope, distance to the coast and to the shelf break, and sea surface temperature) associated with the Risso’s dolphin groups recorded indicate an oceanic distribution pattern, occurring close to the shelf break, what is probably related with foraging activity. This study provides new information about the distribution of Risso’s dolphins in Brazilian waters, and could be used as basis to plan conservation actions.


Padrões de distribuição do golfinho-de-Risso, Grampus griseus, em águas oceânicas do sudeste do Brasil, avaliado através de levantamentos aéreos. O golfinho-de-Risso, Grampus griseus, apresenta ampla distribuição em águas tropicais e temperadas ao redor do mundo. Apesar da ocorrência conhecida ao longo da costa brasileira, informações a respeito da distribuição espacial da espécie são escassas. Neste estudo, avaliamos o padrão de distribuição do golfinho-de-Risso usando registros obtidos através de 200 h de sobrevoos dedicados para observação de mamíferos marinhos no talude e plataforma externa do sudeste do Brasil, conduzidos entre março e maio de 2012. Um total de 16 grupos de golfinhos-de-Risso foi registrado com uma mediana de tamanho de grupo de 35 indivíduos (variação = 1–300). Variáveis ambientais (i.e., profundidade, declividade, distância da costa e para a quebra da plataforma, e temperatura superficial da água) associadas aos grupos de golfinhos-de-Risso registrados indicaram um padrão de distribuição oceânico, ocorrendo próximo da quebra da plataforma continental, o que está provavelmente relacionado com atividade de forrageio. Este estudo fornece novas informações sobre a distribuição dos golfinhos-de-Risso em águas brasileiras, e pode ser usado como base para planejamento de medidas de conservação.