Keyword: Amazon

Diversity of bats of Sierra de la Macarena with comments on their ecological patterns

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The Serranía de la Macarena is an outstanding biodiversity hotspot in the western Amazon because it possesses a high diversity due to the influence of several biogeographic regions, a wide elevational range, and high heterogeneity of vegetation. However, knowledge of the bat richness, composition, and structure is precarious and inventories in the area are scarce. We present a list of bat species for La Macarena based on fieldwork campaigns and information from the literature and biological collections. Based on the fieldwork we conducted, we also describe the diversity patterns of bat assemblages from two contrasting vegetation types: rainforest, and chasmophytic savannas. We registered 73 species from seven families, including nine new records for La Macarena. Forty-eight species were recorded in our sampling sites (35 species in rainforest, and 32 in chasmophytic savannas), while 25 species are reported based on scientific literature and museum specimens. We found ecological differences between the assemblages of both vegetation types related to dominance patterns at the species and ensemble levels. Understory frugivores and nectarivores were the dominant groups in chasmophytic savannas and accounted for 82% of the captures, whereas the canopy frugivores were the most abundant in the rainforest (52%). The differences observed in diversity patterns between both types of assemblages could be associated with highly contrasting vegetation structures and the absence of essential feeding items in chasmophytic savannas. We highlight the need to conduct surveys in new areas to fill the gaps in our knowledge of diversity in this important biodiversity hotspot.

Diversidad de murciélagos de la Serranía de la Macarena, con comentarios sobre sus patrones ecológicos. La Serranía de la Macarena es un punto caliente de biodiversidad en la Amazonía occidental, ya que posee una alta diversidad, producto de la influencia de varias regiones biogeográficas, un amplio rango altitudinal y una alta heterogeneidad de la vegetación. Sin embargo, el conocimiento de la riqueza de especies de murciélagos, su composición y estructura es precario y los inventarios en esta área son escasos. Presentamos una lista con las especies de murciélagos para La Macarena basados en expediciones de campo e información proveniente de literatura científica y colecciones biológicas. Además, describimos los patrones de diversidad de dos ensamblajes de murciélagos en dos tipos de vegetación: bosques húmedos y sabanas casmófitas. Presentamos un total de 73 especies de siete familias, entre las que se incluyen nueve nuevos registros para La Macarena. Hemos registrado 48 especies en campo (35 en bosques húmedos y 32 en sabanas casmófitas), mientras que 25 provienen de registros de la literatura científica y especímenes de colección. Hemos encontrado diferencias ecológicas entre los ensamblajes de ambos tipos de vegetación resumidos en los patrones de dominancia a nivel de especie y de ensambles. Los frugívoros de sotobosque y los nectarívoros fueron los grupos dominantes en las sabanas casmófitas, con el 82% de las capturas, mientras que el grupo de los frugívoros de dosel fue el más abundante en bosques húmedos (52%). Las diferencias observadas en los patrones de diversidad de los ensamblajes pueden estar asociadas con las diferencias contrastantes en la estructura de la vegetación y la ausencia de ítems alimenticios en las sabanas casmófitas. Resaltamos la necesidad de dirigir más exploraciones en nuevas áreas para subsanar los vacíos en el conocimiento de la riqueza de este punto caliente de biodiversidad.

Graphical abstract for the article “Diversity of bats of Sierra de la Macarena with comments on their ecological patterns” (Morales-Martínez et al., 2022)

Cranial morphological variability of a small Neotropical cat revealed by geometric morphometrics

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The jaguarundi (Herpailurus yagouaroundi) has one of the most extensive latitudinal ranges among felids of the Western Hemisphere. Its wide geographic distribution and range of habitats may result in patterns of cranial morphological variation. Thus, we investigated the hypothesis of the existence of morphological ecotypes adapted to specific environments used by the species. The crania of 54 museum specimens from three different ecoregions in Brazil were digitized in ventral, dorsal, and lateral views. No sexual dimorphism was detected. Our hypothesis was supported by the fact that the specimens from the Amazon were significantly larger than those from the Atlantic Forest and Uruguayan savanna. Cranial shape variation between sexes, as well as among ecoregions, was mostly explained by the effect of size. Correlations between geographical distance and cranial shape were not significant. There was a significant correlation between cranium size and latitude, in a pattern that is the reverse of Bergmann’s rule, with larger specimens in lower latitudes. The environmental variables positively correlated with cranium size indicated that larger cats occurred in regions with greater temperature and precipitation. Resource availability might be the cause of the observed variation in cranium size, since jaguarundis probably show different prey size preferences along the species distribution range. However, more ecological data for most ecoregions are needed to test the “resource rule” and to fully understand the patterns and causes of cranial variation in this cat.

Variabilidade morfológica craniana de um pequeno felino neotropical, revelada pela morfometria geométrica. O jaguarundi (Herpailurus yagouaroundi) possui uma das faixas latitudinais mais extensas entre os felídeos do Hemisfério Ocidental. Sua ampla distribuição geográfica e variedade de habitats podem resultar em padrões de variação morfológica do crânio. Assim, investigamos a hipótese da existência de ecótipos morfológicos adaptados aos ambientes específicos utilizados pela espécie. Os crânios de 54 espécimes de museus de três diferentes ecorregiões no Brasil foram digitalizados nas vistas ventral, dorsal e lateral. Não foi detectado dimorfismo sexual no tamanho. Nossa hipótese foi corroborada, pois os espécimes da Amazônia são significativamente maiores do que os da Mata Atlântica e da Savana uruguaia. A variação da forma do crânio entre os sexos, bem como entre ecorregiões, está correlacionada com a variação de tamanho. Correlações entre distância geográfica e forma do crânio não foram significativas. Houve correlação significativa entre tamanho e latitude, em um padrão inverso da regra de Bergmann, com espécimes maiores observados nas menores latitudes. As variáveis ambientais correlacionadas positivamente com o tamanho indicaram felinos maiores ocorrendo em regiões com maior temperatura e precipitação. A disponibilidade de recursos pode ser a causa da variação de tamanho observada, uma vez que aparentemente o jaguarundi preda presas de tamanhos diferentes ao longo de sua distribuição. Porém, são necessários mais dados ecológicos das demais ecorregiões, para testar a “regra do recurso” e elucidar os padrões e causas da variação do crânio deste felino.

Graphical abstract for the article “Cranial morphological variability of a small Neotropical cat revealed by geometric morphometrics” (Prior Migliorini et al., 2021)

Efectos de la tala selectiva y el sexo del hospedador sobre el ectoparasitismo de mamíferos pequeños en bosques del sur de la Amazonía peruana

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Poco se conoce acerca del efecto que la tala selectiva puede tener sobre las relaciones interespecíficas, particularmente entre ectoparásitos y hospedadores. En este estudio se evaluó la prevalencia, la abundancia y la riqueza de ectoparásitos de mamíferos pequeños en bosques con tala de impacto reducido y bosques control en el sur de la Amazonía de Perú. Se usaron modelos lineales generalizados para evaluar el efecto de la tala, la estructura del hábitat y el sexo sobre los ectoparásitos de los hospedadores más representativos: Marmosops, Euryoryzomys, Proechimys y Carollia. No se encontró evidencia de un efecto de la tala sobre la prevalencia y riqueza de ectoparásitos. No obstante, encontramos un efecto positivo de la tala sobre la abundancia de ácaros (Laelapidae) y garrapatas (Ixodidae) en individuos de Marmosops spp. y Proechimys spp. respectivamente, aunque negativo en ácaros de Euryoryzomys spp. Además, los roedores hembra presentaron una mayor cantidad de ectoparásitos. Por otro lado, la abundancia de las moscas de murciélagos (Streblidae) en individuos de Carollia sp. fue menor en bosques con tala. Este estudio es uno de los pocos en abordar el efecto de la tala selectiva con impacto reducido sobre el ectoparasitismo en mamíferos pequeños. Se sugiere ampliar el conocimiento sobre estas interacciones a nivel específico, con estudios sobre las características del hospedador y con una base estacional, lo cual podría aportar a mejorar el entendimiento sobre cómo la actividad antrópica afecta las interacciones entre mamíferos y sus ectoparásitos.

Selective logging and host sex effects on the ectoparasitism of small mammals of the Southern Peruvian Amazon. Little is known about the effect of reduced impact logging on interspecific relationships, particularly the ectoparasite-host relationship. This study assessed the prevalence, abundance, and diversity of ectoparasites of small mammals in forests with reduced impact logging and control plots in southeastern Peruvian Amazon. We used Generalized Linear Models to assess the effect of reduced logging, habitat structure, and host sex on the ectoparasites of the most representative genera: Marmosops, Euryoryzomys, Proechimys, and Carollia. No statistical evidence about an effect of reduced logging on both the prevalence and diversity of ectoparasites were found. However, we found a positive effect of logging on the abundance of mites (Laelapidae) and ticks (Ixodidae) at individual level for Marmosops spp. and Proechimys spp. respectively; but a negative effect on mite abundance in Euryoryzomys spp. In addition, female rodents had a higher amount of ectoparasites. On the other hand, the intensity of the bat flies (Streblidae) in individuals of Carollia spp. was lower in logged forests. This study is one of the few to address the effect of reduced logging on ectoparasitism in small mammals. We suggest expanding the knowledge about the effects of these interactions to a specific level on a seasonal basis, which can provide further information to improve understanding of how this anthropogenic activity affects interactions between mammals and their ectoparasites.

Graphical abstract for the article “Efectos de la tala selectiva y el sexo del hospedador sobre el ectoparasitismo de mamíferos pequeños en bosques del sur de la Amazonía peruana” (Bonifaz & Mena, 2021)

Mammals of Mato Grosso, Brazil: annotated species list and historical review

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The state of Mato Grosso is one of the largest (903,357 km²) and most diverse in terms of vegetation in Brazil, encompassing three distinct Neotropical biomes—the Amazon, Cerrado, and Pantanal—therefore holding high faunal diversity. Our goal in this paper was to review the history of mammalogy in this state, and to provide a checklist of mammals, with comments on taxonomy, distribution, conservation status and type of records for the species present in Mato Grosso. These records were based primarily on voucher specimens housed in scientific collections, but a few were based on personal observations and photographs. We listed 268 species belonging to 149 genera, 36 families and 10 orders, which represent 38% of mammal species occurring in Brazil. The most representative families were Phyllostomidae (63 species), Cricetidae (42) and Didelphidae (31). Our list includes 33 threatened species, representing 12% of Mato Grosso mammal species and 30% of all threatened mammal species of Brazil. We discuss the main threats to this group, and argue that social and political projects together with basic scientific knowledge are urgent to ensure a profound change in the current scenario.

Mamíferos de Mato Grosso, Brasil: lista anotada e revisão histórica. O estado de Mato Grosso é um dos maiores (903 357 km²) e mais diversos do país em termos de fitofisionomias, abrangendo três biomas Neotropicais distintos —Amazônia, Cerrado e Pantanal— apresentando, consequentemente, uma elevada diversidade faunística. Os objetivos do presente estudo foram revisar a história da Mastozoologia neste estado e fornecer uma lista atual de mamíferos com comentários a respeito da taxonomia, distribuição, estado de conservação e tipos de registro para as espécies que ocorrem no Mato Grosso. Os registros aqui obtidos basearam-se, primordialmente, em espécimes-testemunho depositados em coleções científicas, mas algumas espécies foram registradas por observações pessoais e fotografias. Foram registradas 268 espécies pertencentes a 149 gêneros, 36 famílias e 10 ordens, o que representa 38% das espécies de mamíferos do Brasil. As famílias mais representativas foram Phyllostomidae (63 espécies), Cricetidae (42) e Didelphidae (31). Nossa lista inclui 33 espécies ameaçadas, representando 12% das espécies de mamíferos do Mato Grosso e 30% das espécies de mamíferos ameaçados do Brasil. Discutimos as principais ameaças associadas a este grupo e apontamos a importância de projetos sociais e políticos, aliados ao conhecimento científico básico, em promover uma mudança profunda nesse cenário atual.

The genus Dasyprocta Illiger, 1811 (Mammalia: Rodentia) in Colombia

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Two species of Dasyprocta are currently recognized in Colombia. However, the taxonomic history of this genus is complex, with several available names for different populations. Here, we explore intra and interspecific variation of the two species currently recorded in Colombia, D. fuliginosa y D. punctata, and evaluate whether morphological characters allow the separation between specimens from different geographical regions. In addition, we clarify the application of subspecific names to different populations in the country and the distribution patterns of D. punctata subspecies. We show that D. fuliginosa and D. punctata are allopatric in Colombia. D. fuliginosa is distributed in the Amazon, Orinoco and part of the North Andean regions (eastern foothills of the Eastern Cordillera), whereas D. punctata is found in the Caribbean, Chocó and western foothills of North Andean regions of the country. Although there are no clear morphometric or morphological differences in the skull between most taxa, different coat colorations are associated with different geographical regions and contrasting ecosystems. D. punctata candelensis is distributed in the High Magdalena River Basin, North-Andean Province, instead of the Chocó Region as suggested by other authors. D. punctata chocoensis is found in the Colombian Pacific coast and western foothills of the Western Cordillera; D. punctata colombiana is found in the northern part of Colombia in the Caribbean Region. We also found specimens matching the description of D. punctata zuliae from the North-Andean Province in the Eastern Cordillera of Colombia. Despite the present geographic differences in coloration, further revisionary work—including genetic approaches—is needed to further understand the diversity of the genus in Colombia.

El género Dasyprocta Illiger, 1811 (Mammalia: Rodentia) en Colombia. Actualmente se reconocen dos especies del género Dasyprocta en Colombia. Sin embargo, la historia taxonómica del género es compleja, con varios nombres disponibles para diferentes poblaciones. En este trabajo exploramos la variación intra e interespecífica de las dos especies reconocidas en Colombia, D. fuliginosa y D. punctata, y evaluamos los caracteres morfológicos que permiten la separación entre ejemplares procedentes de diferentes regiones geográficas del país. Además, clarificamos la asignación de los nombres subespecíficos a diferentes poblaciones y los patrones de distribución de las subespecies de D. punctata. Dasyprocta fuliginosa y D. punctata son alopátricas en Colombia. Dasyprocta fuliginosa se distribuye en las regiones de la Amazonía, la Orinoquía y parte de la región Norandina (estribaciones orientales de la cordillera Oriental), mientras que D. punctata se encuentra en las regiones Caribe, Chocó y al occidente de la cordillera Oriental en la región Norandina. Aunque no hay variación morfométrica o morfológica craneal entre la mayoría de los taxones, diferentes coloraciones están asociadas con diferentes regiones geográficas y ecosistemas contrastantes. D. punctata candelensis se distribuye en la cuenca alta del río Magdalena, en la provincia Norandina, en lugar de la región del Chocó como ha sido sugerido por otros autores. D. punctata chocoensis se encuentra en la región Pacífica de Colombia y las estribaciones occidentales de la cordillera Occidental; D. punctata colombiana se encuentra en el norte de Colombia en la región Caribe. Además, encontramos ejemplares que se ajustan a la descripción de D. punctata zuliae de la Provincia Norandina en la cordillera Oriental de Colombia. A pesar de las diferencias geográficas de coloración, un trabajo de revisión adicional, que incluya aproximaciones genéticas, es necesario para entender mejor la diversidad de este género en Colombia.

New records of Lampronycteris brachyotis in Brazil

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Lampronycteris is a monotypic genus distributed throughout the Neotropical region. Brazil presents the largest number of reports of L. brachyotis, most of which occur within Amazonia, with only limited records in Cerrado and Atlantic Forest. The present report provides an updated distribution of L. brachyotis in these three biomes, including the first records for the states of Rondônia and Goiás and additional records in the states of Mato Grosso, Pará and São Paulo. We highlight that mesic areas in open formations such as Cerrado might support relictual populations of L. brachyotis, highlighting the importance of these areas for bat diversity.

Nuevos registros de Lampronycteris brachyotis en Brasil. Lampronycteris es un género monotípico de amplia distribución en la región neotropical. Brasil tiene el mayor número de registros de L. brachyotis concentrados en la Amazonía y solo unos pocos registros en el Cerrado y Bosque Atlántico. Este artículo ofrece una actualización de la distribución de L. brachyotis en estos tres biomas, con el primer registro en Rondônia y Goiás, y registros adicionales en los estados de Mato Grosso, Pará y São Paulo. Con los registros presentados aquí, destacamos que los ambientes mésicos presentes en bosque estacional seco, como el Cerrado, pueden mantener poblaciones relictuales de L. brachyotis, destacando la importancia de estas áreas para la diversidad de murciélagos.

Karyotypes of Brazilian representatives of genus Zygodontomys (Rodentia, Sigmodontinae)

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In this article we are reporting two cytotypes found in representatives of Zygodontomys genus trapped in two localities of Brazilian Amazon. From the locality of Surumú (Roraima) were analyzed 12 individuals (cytotype 1) which showed 2n = 86 / FN = 96–100, presenting the two largest pairs (1 and 2) as subtelo-submetacentrics, 4 or 5 medium to small biarmed pairs, the remainder being acrocentric. In Tartarugalzinho (Amapá) 7 specimens which displayed 2n = 84 / FN = 96–98 (cytotype 2) were caught. In both cytotypes the sexual pair is composed by a large submetacentric X chromosome and a median subtelocentric Y chromosome. By G-banding the largest pairs as well as the sex chromosomes could be identified. The C-bands occurred at the centromere of the majority of the autosomes and the short arm of the X and the whole Y chromosomes were heterochromatic. The NOR-bands were prevalently seen at the short arm of one medium and one small acrocentric pairs. Comparing the individuals studied in Brazil with those reported in Venezuela is observed that, although the same or similar diploid numbers, the morphology of the chromosomes of these taxa is quite different, the karyotypes of the specimens from Brazil having a smaller number of biarmed elements.The sexual pair is distinct also, the difference basically concerning to the size of the Y chromosome. Whether these karyotype differences may correspond to different morphological taxa is a subject that deserves further investigations.