Vol. 26 Nº 2

La transformación del ambiente natural constituye la principal amenaza para la conservación de muchas de las especies de mamíferos. La agricultura ha reducido la conectividad del piedemonte de Yungas con el Chaco, limitándola a corredores de hábitats naturales modificados que atraviesan una matriz de zonas transformadas. Mediante relevamientos con cámaras trampa, identificamos las especies medianas y grandes de mamíferos que utilizan corredores boscosos en dos sectores latitudinales del piedemonte de Yungas de Argentina. Estudiamos la diversidad de especies, la influencia de la distancia a través del corredor hasta el bosque continuo sobre la riqueza, cuantificamos similitudes en la composición y estructura de las comunidades entre ambas situaciones ambientales y evaluamos si los corredores constituyen zonas de paso o si los mamíferos establecen sus áreas de acción en los mismos. Registramos 22 especies en los corredores. Solo seis taxones registrados en bosque continuo no fueron documentados en los corredores, y tres fueron fotografiados solo en corredores. Para ambos sectores latitudinales, la equitatividad fue levemente mayor en corredores (aunque las diferencias fueron significativas solo en el sector norte), mientras que la riqueza de especies mostró tendencias opuestas entre sectores latitudinales, siendo mayor en el bosque del sector norte pero menor en el bosque del sector sur (aunque las diferencias no fueron significativas en ningún caso). No encontramos una influencia de la distancia al bosque continuo sobre la riqueza de mamíferos, ni diferencias importantes en la composición y estructura de las comunidades de ambas situaciones ambientales. En el norte, Dasyprocta punctata fue más frecuente en bosques continuos, mientras que Mazama gouazoubira y Leopardus pardalis prefirieron los corredores. En el sur, Leopardus pardalis y Pecari tajacu fueron más frecuentes en bosque continuo, mientras que Didelphis albiventris y las especies omnívoras utilizaron más los corredores. No encontramos diferencias significativas entre especies generalistas y especialistas en el uso de estos hábitats. Nuestro trabajo constituye la primera aproximación a esta temática en la región de las Yungas, aportando información relevante para el establecimiento de políticas de conservación.

Medium and large sized mammals in forested corridors of the yungas’ piedmont of northwestern Argentina. The transformation of the natural environment constitutes the main threat for the conservation of many mammal species. Agriculture has reduced the contact area of the Yungas piedmont forests with the Chaco region to corridors of modified natural habitats which cross the matrix of transformed areas. With camera traps surveys, we identified medium and large sized mammal species that use forested corridors in two latitudinal sectors of the Yungas piedmont forests in Argentina. We studied species diversity, the influence of the distance along the corridor to the continuous forest on species richness, and we evaluated whether the corridors are areas with established populations of these mammals. We recorded 22 species in the corridors. Only six species registered in the continuous forest were not recorded in the corridors, and three were only photographed in the corridors. For both latitudinal sectors, equitability was slightly higher in corridors (although differences only were significant in the northern sector) while species richness was different between latitudinal sectors, higher in the forest of the northern sector, but lower in the forest of the southern sector (although the differences were not significant in any case). We did not find any influence of the distance to the continuous forest on the richness of mammal species nor important differences in the composition and structure of the communities of both environmental situations. In the northern portion, Dasyprocta punctata was more frequently recorded in the continuous forest, whereas Mazama gouazoubira and Leopardus pardalis were more frequently recorded in the corridors. In the southern one, Leopardus pardalis and Pecari tajacu were more frequently recorded in the continuous forest, while Didelphis albiventris and the omnivore species more in the corridors. We did not find significant differences in the use of these habitats between the generalist and specialist species. This is the first study on this topic in the Yungas of Argentina, providing relevant information for the establishment of conservation policies.

Most information available regarding domestic dogs in natural reserves comes from developed countries, particularly North America and Europe, where dogs are usually well managed and cared for. Conversely, in developing country reserves information about dogs are comparatively scarce, particularly in terms of their interactions with local wildlife and their management, despite their high abundance and widespread distribution. We aimed to characterize domestic dog spatial distribution using occupancy modelling and estimate abundance in the Mata das Flores State Park (MFSP). We collected data from January to May 2017. We divided the survey into two sampling protocols: (1) interviews and active search on trails and roads in the region and (2) sand plots to detect the presence of dogs in the MFSP. We recorded a total of 132 individually identified domestic dogs between interviews with surrounding residents and records through active search. We recorded an average of 2 ± 1 dogs per household interviewed. Of this total, we recorded 89 individuals inside the MFSP, through 213 detections in the five months of sampling. Both the spatial distribution map and occupancy models for the species indicated a higher occurrence in the side of the park faced to the urbanized area of Castelo municipality, totaling about 53% of the records. We also obtained a high number of records in the areas near the road that intercepts the park, with about 36% of the records. The remaining 11% of the records occurred in areas close to human settlements around the park. Our results of abundance and spatial distribution together with occupancy modeling could serve to assist conservation planning and management in the MFSP.

Invasão por Canis lupus familiaris (Carnivora) em uma área protegida na Mata Atlântica, Brasil: distribuição espacial e abundância. A maior parte das informações disponíveis relacionadas a presença do cachorro doméstico em reservas naturais são provenientes de países desenvolvidos, particularmente América do Norte e Europa, onde essa espécie geralmente é bem manejada e controlada. Por outro lado, nas reservas localizadas nos países em desenvolvimento o conhecimento sobre essa espécie doméstica é escasso, particularmente em termos das suas interações com a fauna nativa local e seu manejo. Nós objetivamos caracterizar a distribuição espacial do cachorro doméstico utilizando a modelagem de ocupação e estimar a abundância da espécie no Parque Estadual Mata das Flores (PEMF). Nós coletamos dados de janeiro a maio de 2017. Nós dividimos a amostragem em dois protocolos de amostragem: (1) entrevistas e busca ativa em trilhas e estradas da região do parque e (2) parcelas de areia para detectar a presença do cachorro doméstico no PEMF. Nós registramos um total de 132 cães domésticos identificados individualmente entre entrevistas com moradores e registros ao redor através de busca ativa. Registramos uma média de 2 ± 1 cães por domicílio entrevistado. Desse total, registramos 89 indivíduos dentro do PEMF, através de 213 detecções nos cinco meses de amostragem. Tanto o mapa de distribuição espacial quanto os modelos de ocupação da espécie, indicaram uma maior ocorrência no lado do parque voltado para a área urbanizada do município de Castelo, totalizando cerca de 53% dos registros. Também obtivemos um alto número de registros nas áreas próximas à estrada que intercepta o parque, com cerca de 36% dos registros. Os 11% restantes dos registros ocorreram em áreas próximas a assentamentos humanos ao redor do parque. Nossos resultados de abundância e distribuição espacial, juntamente com a modelagem de ocupação, poderiam servir para auxiliar o planejamento e a gestão da conservação no PEMF.

Quantification of morphological diversity among herbivorous mammals and comparisons between herbivorous marsupials and placentals are scarce. In this report we compared morphological variation of the skull and mandible in three representatives of caviid rodents and three species of macropodid marsupials, whose size is comparable, using three-dimensional geometric morphometrics. We applied two levels of comparison, one pointed to a placental-marsupial dichotomy and another pointed to the intra-variation in each group. We also performed an analysis of modularity based on a likelihood approach in order to evaluate different modularity models and analyzing the intra- and inter-module correlation (i.e., morphological integration). Beyond strong morphological differences that split caviids and macropodids along the first axes of the morphospaces of the cranium and mandible, they shared similar allometric shape changes, including the enlargement of muscular attachment areas and lengthening of the diastema. In both clades, the largest value of inter-module correlation (as a measure of modular integration) was found for the oral-nasal and orbit modules. We reported relatively low values of within-module correlation for the oral-nasal and molar modules in macropodids while the opposite was recorded for caviids. Beyond the great differences in cranial structure, one of the factors that influence the patterns of morphological variation and differential integration was the processing of plant matter which seems to induce strong structural changes in both clades, in which the efficiency of the masticatory apparatus is resolved in a similar way.

Morfología cráneo-mandibular en mamíferos herbívoros: macropódidos (Metatheria, Diprotodontia, Macropodidae) y cávidos (Eutheria, Rodentia, Hystricomorpha) como un caso de estudio. La cuantificación de la diversidad morfológica entre mamíferos herbívoros y las comparaciones entre herbívoros marsupiales y placentarios son escasas. En este reporte comparamos la variación morfológica del cráneo y mandíbula en representantes de roedores cávidos y marsupiales macropódidos mediante técnicas de morfometría geométrica en 3D. Aplicamos dos niveles de comparación: uno apuntando a una dicotomía placentario-marsupial y el otro a la variación interna en cada grupo. También realizamos un análisis de modularidad basado en un enfoque de verosimilitud para evaluar diferentes modelos y analizar la correlación intra- e inter-módulo (integración morfológica). Cávidos y macropódidos se separaron en los espacios de forma del cráneo y mandíbula, particularmente sobre el primer eje, mientras que se distribuyeron a lo largo del segundo eje principalmente de acuerdo con la variación de tamaño. Los cambios de forma vinculados al tamaño estuvieron relacionados con la ampliación de las áreas de fijación muscular y el alargamiento del diastema. Los módulos oral-nasal y orbital mostraron los valores más altos de correlación tanto en macropódidos como en cávidos. Se obtuvieron valores de correlación intra-módulo relativamente bajos para los módulos oral-nasal y molar en macropódidos, mientras que se registró lo contrario para los cávidos. Más allá de las grandes diferencias en la estructura craneana, uno de los factores que influye en los patrones de variación morfológica e integración diferencial es el procesamiento de materia vegetal que parece inducir fuertes cambios estructurales que en ambos clados, en los que la eficiencia del aparato masticatorio se resuelve de manera similar.

Infanticide by males is an adaptive behavioral strategy to improve the reproductive success of the perpetrator by increasing their chances to reproduce with the victim female by shortening the inter-birth interval. Thus, females are expected to evolve different counterstrategies towards infanticide by males. We study nest site defense, or future offspring protection, through the direct attack of pregnant females close to give birth against potentially infanticidal males in the Pampean grassland mouse (Akodon azarae). We experimentally test the prediction that pregnant females are more aggressive against unfamiliar intruder males than non-pregnant females, and that the intensity of this aggressive response is independent of females residence durations in their home territory. We conducted 46 behavioral trials between resident females (pregnant or non-pregnant) and unfamiliar intruder males, considering different residence durations of females in their own individual enclosure (48 and 72 hours). We found that pregnant females were always more aggressive than non-pregnant females, independently of residence duration. Our research provides evidence that aggressive behavior of future mothers of A. azarae to defend the nest site would reduce infanticide risk of their young next to be born; keeping away potential infanticidal males could reduce the greater cost of avoiding infanticide of their vulnerable offspring (i.e., when they become lactating females). In this way, even though aggression is risky, it would be advantageous for pregnant females to use aggression even when there are not yet any pups to protect.

Comportamiento agresivo de las hembras preñadas de Akodon azarae: ¿una estrategia para reducir el riesgo de infanticidio de sus crías próximas a nacer? El infanticidio por parte de machos es una estrategia adaptativa que incrementa el éxito reproductivo del agresor al aumentar sus posibilidades de reproducirse prontamente con la víctima. Así, se espera que en las hembras evolucionen contraestrategias hacia el infanticidio por parte de machos. Nosotros estudiamos la defensa de nidos, o protección de futuras crías, a través de la agresión de hembras preñadas, próximas a parir, hacia machos potencialmente infanticidas en el ratón de pastizal pampeano (Akodon azarae). Probamos experimentalmente la predicción que las hembras preñadas son más agresivas hacia los machos intrusos que las no preñadas, y que la intensidad de esta respuesta agresiva es independiente del tiempo de residencia de las hembras en sus clausuras individuales. Realizamos 46 enfrentamientos comportamentales entre hembras residentes (preñadas y no preñadas) y machos intrusos desconocidos, considerando el tiempo de residencia de las hembras (48 y 72 horas). Independientemente de la duración de la residencia de las hembras, las preñadas siempre fueron más agresivas que las no preñadas. Nuestra investigación proporciona evidencia de que el comportamiento agresivo de las futuras madres de A. azarae para defender el sitio del nido reduciría el riesgo de infanticidio de sus crías próximas a nacer; mantener alejados a potenciales machos infanticidas podría reducir el mayor costo de evitar el infanticidio de sus crías vulnerables (es decir, cuando son lactantes). De esta manera, aunque la agresión es riesgosa, sería ventajoso para las futuras madres usar la agresión incluso cuando todavía no hay crías para proteger.

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.

Con base en ejemplares recolectados en los Andes surorientales de Ecuador, Parque Nacional Sangay, pero también integrando otros materiales de colecciones, se efectuó una revisión del grupo «cinereus» del género de cricétidos Thomasomys Coues, 1884 (Sigmodontinae, Thomasomyini). Como resultado de dicha revisión, además de proponerse una hipótesis filogenética basada en el marcador molecular Cyt-b, se reconoce una nueva especie. Se trata de un Thomasomys de tamaño corporal mediano dentro del género, que se distingue, entre otros caracteres, por presentar una cola larga, amplia separación entre almohadillas tenar e hipotenar, largo de la serie molar superior < 5.6 mm, ancho de placa cigomática < 2.9 mm, vacuidades esfenopalatinas en forma de fisuras, margen posterior de los nasales sobrepasando el nivel de los lacrimales, M1 con anterolofo grueso y mesolofo estrecho, M2 con mesolofo corto, m1 con mesolófido delicado y m2 con mesolófido diminuto. Esta nueva especie de Thomasomys, por el momento endémica del Parque Nacional Sangay, presenta una distancia genética de 9.18% con respecto a T. caudivarius, su especie hermana que habita en los Andes suroccidentales de Ecuador. Con este hallazgo, la riqueza de Thomasomys en Ecuador asciende a 15 especies, comparable con aquella registrada en Colombia. Finalmente, se propone la necesidad de mancomunar esfuerzos para generar avances sustanciales en el conocimiento de este complejo género de sigmodontinos andinos.

Unexpected diversity in the Andes of Ecuador: phylogeny of the Thomasomys “cinereus” group and description of a new species (Rodentia, Cricetidae). Based on specimens collected in the southeastern Andes of Ecuador, at Parque Nacional Sangay, but also including animals from mammal collections, a revision of the species of the group “cinereus” of the cricetid genus Thomasomys Coues, 1884 (Sigmodontini, Thomasomyini) was made. As a result, concomitantly to a new phylogeny based on a molecular marker (Cytb), a new species is recognized. It corresponds to a medium-sized Thomasomys which can be distinguished from the other species of the genus by the following traits: long tail, broad space between thenar and hypothenar pads, length of the maxillary toothrow < 5.6 mm, breadth of zygomatic plate < 2.9 mm, sphenopalatine vacuities as slits, posterior margin of nasals surpassing the level of the lacrimals, M1 with broad anteroloph and narrow mesoloph, M2 with short mesoloph, m1 with delicate mesolophid, and m2 with minute mesolophid. The new species of Thomasomys, at the moment endemic for the Parque Nacional Sangay, shows a genetic distance of 9.18% with respect to its sister species, T. caudivarius, which inhabits the southwestern Andes of Ecuador. With the reported finding, the richness of Thomasomys in Ecuador increases to 15 species and rivals that registered in Colombia. Finally, we pose the necessity to join efforts in order to produce a significant advance in the knowledge of this complex genus of Andean sigmodontines.

La ganadería impacta los ecosistemas, particularmente a través del consumo y dispersión de especies introducidas que afectan la flora nativa. La dispersión de semillas de vegetación introducida por mamíferos exóticos es un ejemplo de facilitación entre especies exóticas. En este trabajo se abordaron tres aspectos (composición de la dieta, viabilidad y germinación de semillas) para evaluar el rol del ganado doméstico en la dispersión de Rosa rubiginosa, rosa mosqueta, en bordes de vegas de baja altura en la provincia de Mendoza. Se recolectaron heces frescas de ganado vacuno y equino (n = 60), y se contabilizaron las semillas enteras de Rosa rubiginosa. La dieta de ambas especies estuvo conformada principalmente por flora nativa, sobre todo gramíneas (Poaceae). Tanto la vaca como el caballo aumentaron la tasa de germinación de las semillas enteras de rosa mosqueta en comparación con los controles establecidos. Ambos herbívoros introducidos utilizan la rosa mosqueta como un recurso importante y actúan como dispersores legítimos de sus semillas.

Role of domestic livestock in the colonization of the invasive species mosqueta rose (Rosa rubiginosa L.) in the arid Andes, Argentina. Livestock impacts ecosystems, particularly through the consumption and dispersion of introduced plant species that affect native flora. The dispersion of seeds introduced by exotic mammals is an example of facilitation among exotic species. In this work, three aspects (diet composition, viability and germination of seeds) were approached to evaluate the role of domestic livestock in the dispersion of Rosa rubiginosa, sweetbriar rose, on edges of low-altitude vegas in Mendoza province. Fresh feces were collected from cattle and horses (n = 60), and the intact seeds of Rosa rubiginosa were counted. The diet of both species was mainly made up of native flora, especially grasses (Poaceae). Both cows and horses increased the germination rate of intact sweetbriar rose’s seeds compared to established controls. We can highlight that both introduced herbivores use sweetbriar rose as an important resource and act as legitimate dispersers of their seeds.

We analyzed the diet composition of Monodelphis domestica (Wagner, 1842) distributed in a high-altitude rocky habitat (campo rupestre) in Southeastern Brazil, between October 2015 and December 2016. We also evaluated whether there are diet differences depending on body mass, sex and seasons. We collected 70 fecal samples of 29 M. domestica specimens and recorded five food categories (arthropods, vertebrates, seeds, flowers and plant vegetative parts). Monodelphis domestica presented a specialized diet, the specimens mainly fed on invertebrates (found in 100% of the samples). The samples also presented plant vegetative parts (leaves and stems), flowers and small vertebrates (scales and fragmented bones of lizards, snakes and birds). The species showed seasonal diet variations and consumed large portions of arthropods, small portions of vertebrates and plant vegetative parts during the rainy season. Intersexual differences influenced the diet composition: the range of food items consumed by males was wider than that ate by females. Our findings helped better understanding the food ecology of short-tailed opossums, besides being the first study about the diet of a didelphid species distributed in high-altitude rocky habitats.

Variações na dieta da cuíca-de-rabo-curto Monodelphis domestica (Didelphimorphia, Didelphidae) devido a fatores sazonais e intersexuais. Analisamos a composição da dieta de Monodelphis domestica (Wagner, 1842) em uma área de campos rupestres no sudeste brasileiro, entre outubro de 2015 e dezembro de 2016. Também avaliamos se existem diferenças na dieta de acordo com a massa corporal, sexos e estações do ano. Obtivemos 70 amostras fecais de 29 indivíduos e 5 categorias de itens alimentares foram identificadas (artrópodes, vertebrados, sementes, flores e partes vegetativas de plantas). Monodelphis domestica apresentou uma dieta especializada consumindo principalmente artrópodes (registrados em 100% das amostras). As amostras também apresentaram partes vegetativas (folhas e caules), flores e pequenos vertebrados (escamas e ossos fragmentados de lagartos, serpentes e aves). A espécie mostrou variação sazonal na dieta, consumindo uma alta proporção de artrópodes, pequenos vertebrados, e partes vegetativas de plantas durante os meses chuvosos. Houve também diferença intersexual na composição da dieta, com machos consumindo um espectro mais amplo de itens do que as fêmeas. Nossos resultados contribuem para a compreensão da ecologia alimentar das cuícas-de-cauda-curta, e representa o primeiro estudo específico sobre a dieta de didelfideos em campos rupestres.

Eptesicus (Histiotus) magellanicus is a relatively rare and poorly known Patagonian endemic. This species is currently recognized as a valid, but until recently some authors treated it as a subspecies of E. (H.) montanus. In fact, no molecular data exist to support the distinctiveness of the former. In Patagonia, the distribution of these two species overlap marginally; they are also sympatric with a third Histiotus species, E. (H.) macrotus. In this study, we present for the first time molecular data that corroborate morphological evidence of the separation between E. (H.) magellanicus from other Eptesicus (Histiotus) species, in special the ones with which it shares its distribution. We sequenced a nuclear intron (THY) and the cytochrome b (Cyt b) gene from specimens of E. (H.) magellanicus, E. (H.) montanus, and E. (H.) macrotus, collected in the Chubut Province (Argentina), and from an undescribed Eptesicus (Histiotus) species from Peru. We included these sequences in a phylogenetic analysis together with previously published sequences of four typical Eptesicus species. The THY intron showed very little variation, while the Cyt b phylogeny recovered three highly supported Histiotus clades. A highly supported clade comprising all specimens of E. (H.) magellanicus was the first to split off Histiotus, suggesting that the Andean region was important during the early diversification of the genus. Unexpectedly, the clade containing the specimens of E. (H.) macrotus and E. (H.) montanus showed no internal resolution, either questioning their mutual identity as a separate species, or suggesting the occurrence of local hybridization and introgression.

Diferenciación genética mitocondrial y relaciones filogenéticas entre tres especies de Eptesicus (Histiotus) en una zona de contacto en la Patagonia. Eptesicus (Histiotus) magellanicus es una especie endémica de Patagonia, relativamente rara y pobremente conocida. Actualmente Eptesicus (Histiotus) magellanicus es reconocida como especie válida; sin embargo, recientemente ha sido considerada como subespecie de Eptesicus (H.) montanus por algunos autores. En Patagonia estas dos especies solapan sus distribuciones marginalmente, donde además son simpátricas con una tercera especie, Eptesicus (H.) macrotus. En este estudio presentamos por primera vez datos moleculares que corroboran la evidencia morfológica que diferencian a E. (H.) magellanicus del resto de las especies de Histiotus, en especial con aquellas con las que comparte su distribución. Se secuenciaron un intron del gen de la tirotropina y gen citocromo b para especímenes de E. (H.) magellanicus, E. (H.) montanus, y E. (H.) macrotus, colectados en la provincia del Chubut (Argentina), y dos ejemplares de Eptesicus (H.) sp. de Perú. Analizamos sus secuencias junto con otras previamente publicadas para cuatro especies típicas de Eptesicus. El gen tirotropina mostró muy poca variación, mientras que la filogenia obtenida con el gen citocromo b recuperó tres clados de Histiotus fuertemente soportados. El clado que incluyó a todos los especímenes de E. (H.) magellanicus fue el primero en separarse dentro de Histiotus, sugiriendo que la región andina fue importante durante la diversificación temprana del género. Inesperadamente, el clado que contenía las muestras de E. (H.) macrotus y de E. (H.) montanus no mostró resolución interna, sugiriendo dos posibles alternativas, la existencia de una única especie o la ocurrencia de hibridación e introgresión local.

Despite the substantial economic and human health problems produced by rodents of the genus Rattus almost nothing is known about its actual dispersal. In the present study we analyze the genetic subdivision of R. norvegicus inhabiting poultry farms of Buenos Aires, Argentina, and the relation between geographic and genetic distances by means of variation in microsatellite loci. We genotyped 40 rats captured between April-06 and June-07 from nine poultry farms distributed in an area of 110 km². No genetic subdivision was found among different poultry farms. This result supports the hypothesis of high connectivity between R. norvegicus inhabiting poultry farms in Buenos Aires. Because this species is a known host of diverse zoonosis as leptospirosis and trichinosis, our results point out that there is a great risk of transmission for distances lower than 12 km. Health control and preventive measures should therefore be applied simultaneously in all nearby poultry farms.

Conectividad entre las subpoblaciones de rata noruega (Rattus norvegicus) que habitan granjas avícolas de Exaltación de la Cruz, Buenos Aires, Argentina. A pesar de los problemas económicos y de salud producidos por roedores del género Rattus, se conoce muy poco sobre su dispersión efectiva. En el presente estudio analizamos la subdivisión genética de las subpoblaciones de R. norvegicus que habitan granjas avícolas de Buenos Aires, Argentina, y la relación entre las distancias geográficas y genéticas por medio de la variabilidad en loci de microsatélites. Se genotiparon 40 ratas capturadas entre abril-06 y junio-07 en nueve granjas avícolas distribuidas dentro de un área de 110 km². No se encontró subdivisión genética entre las diferentes granjas avícolas. Esto apoya la hipótesis de alta conectividad entre R. norvegicus que habitan granjas avícolas en Buenos Aires. Debido a que R. norvegicus es un conocido hospedador de diversas zoonosis como leptospirosis y triquinosis, nuestros resultados indican que existe un gran riesgo de transmisión para distancias menores a 12 km. Las medidas de control y prevención sanitarias deberían, por lo tanto, aplicarse en todas las granjas cercanas en forma simultánea.

Understanding basic feeding ecology of wild animals is paramount to comprehend interspecific interactions. This is evident for three sympatric wild canids species in an unprotected ecotone between the Cerrado savanna and the Atlantic Forest ecosystems: hoary foxes (Lycalopex vetulus), crab-eating foxes (Cerdocyon thous) and maned wolves (Chrysocyon brachyurus). Their omnivorous diets may lead to competition, but knowledge gaps hinder assessments of their conservation status and how feeding habits influence potential niche overlaps. We analyzed fecal samples collected along seven years to determine how these canids utilize food resources. Insects were the main food category for both hoary and crab-eating foxes, while fruits were more important for maned wolves. Niche breadth analyses revealed narrow diet breadths for the hoary and crab-eating foxes, and medium for the maned wolf. Both smaller species presented a less diverse diet, consuming few resources very frequently and multiple resources less frequently. Niche overlap was high between hoary and crab-eating foxes, totaling 66.1% for food items and 80.8% for categories, medium between crab-eating foxes and maned wolves (36.5% for items and 52.8% for categories), and low between hoary foxes and maned wolves for food items (25.1%) and medium for categories (34.1%). Overall, our study indicates that trophic niche differences associated to termite consumption by hoary foxes and fruits by maned wolves are critical for their coexistence in unprotected Cerrado areas.

Sobreposição de nicho trófico e partilha de recursos entre canídeos silvestres em um ecótono neotropical antropizado. Estudar a ecologia alimentar básica de espécies de animais silvestres é fundamental para compreender interações interespecíficas. Isto é evidente para três espécies de canídeos silvestres simpátricos em um ecótono desprotegido entre os ecossistemas do Cerrado e da Mata Atlântica: raposinha-do-campo (Lycalopex vetulus), cachorro-do-mato (Cerdocyon thous) e lobo-guará (Chrysocyon brachyurus). Suas dietas onívoras podem levar à competição, mas as lacunas de conhecimento dificultam a avaliação de seu estado de conservação e como os hábitos alimentares influenciam potenciais sobreposições de nicho. Analisamos amostras fecais coletadas ao longo de sete anos para determinar como esses canídeos utilizam os recursos alimentares. Os insetos foram a principal categoria de alimento tanto para as raposinhas quanto para os cachorros, enquanto frutos foram mais importantes para os lobos-guará. Análises de amplitude de nicho revelaram baixa uniformidade na utilização dos recursos para raposinhas e cachorros, e média para o lobo-guará. As duas espécies menores apresentaram uma dieta menos diversificada, consumindo poucos recursos em altas frequências e muitos recursos em baixas frequências. A sobreposição de nicho foi alta entre as raposinhas e cachorros, totalizando 66.1% para itens alimentares e 80.8% para as categorias, média entre cachorros e lobos-guará (36.5% para itens e 52.8% para categorias) e baixa entre as raposinhas e lobos-guará para itens (25.1%) e média para categorias (34.1%). No geral, nosso estudo indica que as diferenças de nicho trófico associadas ao consumo de cupins por raposinhas e frutos por lobos-guará são fundamentais para sua coexistência em áreas de Cerrado desprotegidas.

Colombia es el país con el mayor número de especies de murciélagos en el mundo. Sin embargo, el conocimiento sobre sus ectoparásitos se limita a unas pocas listas de especies y a la descripción de la composición y estructura de la artropodofauna parásita de murciélagos en un bosque húmedo tropical y un bosque seco tropical. Recientemente se ha evidenciado que los ensamblajes de murciélagos en ecosistemas de sabanas de la Orinoquía son altamente diversos; consecuentemente, el conocimiento sobre sus ectoparásitos es aún incipiente. El objetivo de este trabajo es presentar por primera vez un listado de los ectoparásitos de murciélagos en un ecosistema de sabanas inundables en el departamento de Casanare, en los Llanos Orientales de Colombia. Se examinaron 102 murciélagos de ocho especies y se encontraron 18 especies de ectoparásitos. Estos ectoparásitos corresponden a seis familias y cinco órdenes como sigue, Diptera: Streblidae (9 spp.); Mesostigmata: Spinturnicidae (3 spp.) y Macronyssidae (3 spp.); Astigmata: Labidocarpidae (1 sp.); Ixodida: Ixodidae (1 sp.); Hemiptera: Polyctenidae (1 sp.). Se reportan por primera vez para Colombia las especies Strebla tonatiae, Pseudostrebla greenwelli, Hesperoctenes eumops, Chiroptonyssus haematophagus y Parakosa flexipes. Adicionalmente, se registra la infestación de murciélagos por una garrapata ixódida y también a Tonatia saurophila como nuevo hospedador para S. tonatiae y P. greenwelli.

New records of bat ectoparasites in floodplains ecosystems of the Colombian Orinoquia. Colombia is the country with the highest number of the bat species in the world. However, knowledge about bat ectoparasites is limited to a few general species lists and to the description in terms of composition and structure of bat parasitic arthropodofauna in a tropical rain and tropical dry forest. Recently, it has been evidenced that bat assemblages in savanna ecosystems of the Orinoquia region are highly diverse; consequently, knowledge about their ectoparasites is still unknown. The objective of this work is to present for the first time a list of bats ectoparasites in a floodplain savanna ecosystem in the department of Casanare, in the Colombian Llanos. We examined 102 bats belonging to eight species; we found 18 ectoparasite species. These parasites correspond to six families and five orders as follows, Diptera: Streblidae (9 spp.); Mesostigmata: Spinturnicidae (3 spp.) and Macronyssidae (3 spp.); Astigmata: Labidocarpidae (1 sp.); Ixodida: Ixodidae (1 sp.); Hemiptera: Polyctenidae (1 sp.). We report for the first time in Colombia the species Strebla tonatiae, Pseudostrebla greenwelli, Hesperoctenes eumops, Chiroptonyssus haematophagus and Parakosa flexipes. Additionally, we register the infestation by an Ixodid tick in bats and also, we report the species Tonatia saurophila as a new host for S. tonatiae and P. greenwelli.

El yaguareté (Panthera onca) es el felino más grande de América. En Argentina sus poblaciones han disminuido en forma alarmante y se lo considera En Peligro Crítico. El objetivo fue realizar el primer relevamiento sistemático de la presencia y actividad del yaguareté en el Parque Nacional Baritú, en la ecorregión de las Yungas. Se establecieron a distancias promedio de 2–3 km 28 estaciones independientes de muestreo con dos cámaras cada una. Se realizaron muestreos de agosto a noviembre de 2014 y 2015, y entre agosto y septiembre de 2016 y 2017. El área de muestreo fue de 608.1 km². Se obtuvieron 98 registros: 43 (2014), 18 (2015), 19 (2016) y 18 (2017), de al menos nueve individuos de yaguareté en 5153 días/cámara (19 detecciones cada 1000 días/cámara). No hubo detecciones confirmadas de hembras ni de juveniles. El promedio de densidades mínimas anuales fue de 0.95/100 km², y la densidad mínima combinada (todos los muestreos) fue de 1.15 individuos/100 km². La actividad fue mayormente crepuscular (7:00–9:00 h y 18:00–19:00 h) con variación anual pero consistente con lo reportado para esta especie. Las presas más abundantes fueron el tapir (Tapirus terrestris) y dos especies de corzuela (Mazama sp.). Es probable que la densidad de yaguaretés en este parque nacional sea una de las más altas de Argentina. Es necesario profundizar estos estudios para incrementar la información respecto de la situación de esta y de otras especies en esta zona de tanta importancia para la conservación en Argentina.

Jaguar (Panthera onca) in the yungas of Baritú National Park, Argentina: minimum density, daily activity, and potential prey. The jaguar (Panthera onca) is the largest wild cat in the Americas. In Argentina, populations have decreased significantly and it is considered Critically Endangered. We performed the first systematic survey of the presence and activity of the jaguar within Baritú National Park, in the Yungas ecoregion. Twenty-eight independent stations were established with two camera traps each, with an average distance of 2–3 km among them. Samplings were carried out from August to November in 2014 and in 2015, and from August and September in 2016 and in 2017. A total of 98 records were obtained (43 in 2014, 18 in 2015, 19 in 2016, and 18 in 2017) of at least 9 individuals in 5153 camera days, resulting in 19 detections every 1000 camera days. Noteworthy was the lack of confirmed females or juveniles detected. The average minimum annual density (individuals/area) was 0.95/100 km², and the combined minimum density (all surveys) was 1.15/100 km². The jaguar’s activity was mostly crepuscular (7:00–9:00 h and 18:00–19:00 h), with some individual variation but consistent with what is reported for this species. The most abundant prey species were the tapir (Tapirus terrestris) and two species of brocket deer (Mazama sp.). The density of jaguars in this national park is potentially one of the highest in Argentina. Extending these studies is necessary to increase information regarding the situation of this and other species in this area of great conservation relevance in Argentina.

Morphology studies provide knowledge that allow us to understand how animals interact with the natural environment or in captivity. The aim of this study was to describe the origin and antimeric distribution of brachial plexus nerves and the innervated muscles in Bradypus variegatus. Twelve adults three-toed sloths were used, arising from the Serra dos Órgãos National Park and Wild Animals Rehabilitation Center of Estácio de Sá University, and donated to Animal and Human Anatomy Department of the Rural Federal University of Rio de Janeiro. The specimens were fixed in formaldehyde solution for infusion to 10%. Data were presented in absolute and percentage frequency simple. The brachial plexus originated the suprascapular, subscapular, radial, median, ulnar and musculocutaneous nerves for the intrinsic musculature and the cranial pectoral nerves, caudal pectoral, lateral thoracic, long thoracic, thoracodorsal nerves for the extrinsic musculature. The spinal branches involved in the formation of the plexus were C8, C9, C10, T1 and T2. The branches that contributed most were ventral spines C8 and C9.

O plexo braquial na preguiça-bentinha (Bradypus variegatus Schinz, 1825): uma análise descritiva e comparativa. Estudos de morfologia fornecem conhecimentos que permitem entender o modo como os animais interagem com o ambiente natural ou em cativeiro. O objetivo desse estudo foi descrever a origem e a distribuição antimérica dos nervos do plexo braquial e os músculos inervados em Bradypus variegatus. Foram utilizadas 12 preguiças adultas com mortes de diferentes causas naturais no Estado do Rio de Janeiro. Os espécimes foram fixados com perfusão de solução de formaldeído a 10%. Os dados foram representados em frequência absoluta e percentual simples. Os plexos braquiais originaram os nervos supraescapular, subescapular, radial, mediano, ulnar e musculocutâneo para a musculatura intrínseca e os nervos peitoral cranial, peitoral caudal, torácico lateral, torácico longo, toracodorsal para a musculatura extrínseca. Os ramos espinhais envolvidos na formação do plexo foram C8, C9, C10, T1 e T2. Os ramos que mais contribuíram em suas formações foram C8 e C9.

Information about the social relations among individuals is essential to define and develop management plans for a socially structured population. Association data for 25 adult Lahille’s bottlenose dolphins were obtained from 189 photo-identification surveys that took place between January 2007 and May 2009 in La Coronilla-Cerro Verde and Cabo Polonio, Rocha, Uruguay. Group size averaged 5.22 individuals (SD = 3.77, n = 255). Coeficients of association were calculated using the Half-Weight Index. Most of the associations were weak (79.7%) and variation of real association indices was greater than would be expected by chance. Thus, the null hypothesis that individuals associated randomly was rejected. Standardized Lagged Association Rate analysis also indicated that nonrandom associations between individuals persisted over the study period. The exponential decay model that fits best to the data suggested the existence of constant companions and casual acquaintances. This study is the first report about the social structure of the population of Lahille’s bottlenose dolphin inhabiting the Uruguayan marine coasts. Cerro Verde and Cabo Polonio were the first marine protected areas selected by the government of Uruguay. However, information about the ecology and behavior of the species in these areas is still insufficient. It is recommended that the results of this study be taken as baseline information to assess the conservation status of this population, as well as for the development of adequate conservation and management plans.

Estructura social de la tonina Tursiops truncatus gephyreus (Cetacea: Delphinidae) en la costa atlántica uruguaya. Para una población socialmente estructurada, disponer de información sobre las relaciones sociales entre individuos es esencial para definir y desarrollar planes de manejo. Se obtuvieron datos de asociación para 25 toninas adultas a partir de 189 salidas de foto-identificación, realizadas entre enero 2007 y mayo 2009, en La Coronilla-Cerro Verde y Cabo Polonio, Rocha, Uruguay. El tamaño grupal promedió 5.22 individuos (DS = 3.77, n = 255). Los coeficientes de asociación se calcularon utilizando el Índice de Peso Medio. Las asociaciones fueron mayormente débiles (79.7%) y la variación de los índices de asociación fue mayor que lo esperado por azar. Por tanto, se rechazó la hipótesis nula de que los individuos se asociaron aleatoriamente. El análisis utilizando la Tasa de Asociación con Retardo Estandarizada también indicó que asociaciones no aleatorias persistieron durante el período de estudio. El modelo exponencial que mejor ajusta a los datos sugiere la existencia de compañeros constantes y compañeros casuales. Este estudio reporta por primera vez información sobre la estructura social de la población de toninas que habita la costa marina uruguaya. Cerro Verde y Cabo Polonio fueron las primeras áreas marinas protegidas por el gobierno de Uruguay. Sin embargo, aún es insuficiente la información sobre la ecología y el comportamiento de la especie en estas áreas. Se recomienda que los resultados de este estudio se tomen como información de base para evaluar el estado de conservación de esta población, así como para el desarrollo de planes adecuados de manejo y conservación.

Glyphonycteris is a poorly known genus of bats that inhabit lowlands and forested mountains of Central and South America. This genus comprises three nominal species, with G. sylvestris being the most widely distributed species in South America. The karyological data previously available for this genus are restricted to those resulting from conventional staining techniques applied to a few specimens from Surinam. Here, we report the first record of G. sylvestris in Argentina extending its southern distribution. Moreover, our new locality represents the seventh record from the Atlantic Forests Biome and the first from Araucaria Moist Forest ecoregions. Our specimen overall exhibits the diagnostic characteristics described for the species except for some differences in the distribution of hairs on the wings and limbs. The fecal sample obtained from our specimen contained only seeds of Piper aduncum. The karyotype was 2n = 22 with a FN = 42; the analysis of fluorochrome banding patterns in the chromosomal pericentromeric regions shows DAPI (4,6-diamidino-2-phenylindole) positive blocks in pairs 5 and 8, whereas pericentromeric regions stained with CMA₃ (Chromomicine A₃) are positive in pairs 1, 2, 3, 4 and 11. Moreover, the interstitial region of chromosomes shows DAPI and CMA₃ positive blocks in pairs 1, 2, 3, 4 and 5. These karyological data are novel to G. sylvestris, contributing to the scarce knowledge of the genus. Thus filling blanks of information and enabling further comparative chromosome analysis.

Primer registro de Glyphonycteris sylvestris Thomas, 1896 (Chiroptera: Phyllostomidae: Glyphonycterinae) para Argentina, con comentarios sobre su cariotipo. Glyphonycteris es un género poco conocido de murciélago que habita los bosques de tierras bajas y de montañas de Centroamérica y Sudamérica. Este género incluye tres especies nominales, donde G. sylvestris es la más ampliamente distribuida al sur de Sudamérica. Los datos de cariotipo para este género están restringidos a técnicas de tinción convencional realizadas sobre unos pocos especímenes de Surinam. En este trabajo se presenta el primer registro de G. sylvestris en Argentina, extendiendo su distribución sur. Además, esta nueva localidad representa el séptimo registro para el Bioma del Bosque Atlántico y el primero para la ecorregión de los Bosques Húmedos de Araucaria. Nuestro espécimen exhibe los caracteres diagnósticos para la especie excepto por algunas diferencias en la distribución de los pelos en alas y miembros. La muestra fecal obtenida de nuestro espécimen solo contenía semillas de Piper aduncum. El cariotipo tuvo un 2n = 22 y FN = 42; los patrones de bandeo con fluorocromos en la región pericentromérica muestra bloques de DAPI (4,6-diamino-2-fenilindol) positivo en los pares 5 y 8, mientras que las regiones pericentroméricas teñidas con CMA₃ (Chromomicina A₃) son positivas en los pares 1, 2, 3, 4 y 11. Además, en las regiones intersticiales de los cromosomas se observaron bloques DAPI y CMA₃ positivos en los pares 1, 2, 3, 4 y 5. Estos datos cariológicos son novedosos para G. sylvestris, contribuyendo al escaso conocimiento del género. Por ende, llenan un vacío de información que permitiría futuros análisis cromosómicos comparativos.

Genetic analyses of kinship can generate important insights into social structure, particularly for species for which direct observations of social relationships are challenging. We used molecular markers to characterize the kin structure of a population of the Río Negro tuco-tuco (Ctenomys rionegrensis), a subterranean species of rodent that is rarely observed above ground. Previous research has revealed that adults of this species engage in at least periodic episodes of burrow sharing, indicating that C. rionegrensis may not be strictly solitary. To explore the kin structure of this species, we used variability at 10 microsatellite loci to determine if (1) adults and juveniles captured at the same burrow entrance were parents and offspring and (2) kinship among adults captured together differed from that among randomly sampled pairs of individuals in our study population. Our analyses revealed that adults and juveniles captured together were not typically parents and offspring, suggesting potential mixing of litters among burrow systems. Relatedness among adults captured together did not differ from background levels of genetic similarity, providing no evidence that spatial proximity was associated with kin structure. Collectively, our findings support the hypothesis that C. rionegrensis is not strictly solitary but instead engages in burrow sharing by adults and associated litters of young.

Análisis genéticos sugieren la existencia de madrigueras compartidas en los tucu-tucus de Río Negro (Ctenomys rionegrensis). Los análisis genéticos de parentesco pueden generar importantes ideas sobre la estructura social, particularmente en especies donde las observaciones directas de las relaciones sociales son aún muy discutidas. Utilizamos marcadores moleculares para caracterizar la estructura de parentesco en una población de los tuco-tucos de Río Negro (Ctenomys rionegrensis), una especie de roedores subterráneos que rara vez se observa sobre la superficie. Investigaciones anteriores han revelado que los adultos de esta especie pueden compartir madrigueras, al menos por periodos, indicando que esta especie puede no ser estrictamente solitaria. Para explorar la estructura de parentesco de esta especie utilizamos la  variabilidad presente en 10 loci de microsatélites para determinar si (1) adultos y juveniles capturados en la misma madriguera son padres e hijos y (2) el parentesco entre los adultos capturados en las mismas cuevas difiere del de pares de individuos muestreados al azar en la población estudiada. Nuestros análisis revelaron que los adultos y los juveniles capturados juntos típicamente no están emparentados, lo que sugiere una posible mezcla de camadas dentro del sistema de madrigueras. El parentesco entre los adultos capturados juntos, sin embargo, no difirió de los niveles medios de similitud genética, sin proporcionar evidencia de que la proximidad espacial estuviera asociada con la estructura de parentesco. En conjunto, nuestros hallazgos apoyan la hipótesis de que C. rionegrensis no es una especie estrictamente solitaria, sino que existe intercambio de madrigueras entre los adultos y sus camadas asociadas.

Identifying factors that influence the importance of species for mutualistic interactions is crucial for designing management and conservation strategies that aim to conserve ecosystem functions. Even though bats are key seed-dispersers, factors that influence their importance for structural properties of seed-dispersal networks are poorly studied. We evaluated the influence of cranial morphology, phylogenetic legacy and abundance of frugivorous bats on the structural properties of an interaction network in a tropical dry forest. Consequently, we captured bats and identified interactions with plants by collecting and identifying seeds from fecal samples. Then, we described network structure by using network-level indexes and assessed the contribution of bats to network structure by using species-level indexes. Analysis of the mutualistic network indicated that: (1) there are few species with high number of interactions, (2) the structure was more compartmentalized and less nested than expected, (3) there are subgroups of bats and plants that are highly connected among them, and (4) network would collapse promptly with the loss of bats with most interactions (generalist). Furthermore, bats that contribute the most to network structure tended to have short rostrum and wide cranium and/or were abundant, with Artibeus lituratus being the most important bat; however, contribution to network structure did not have phylogenetic signal. According to the interaction neutrality hypothesis, species’ abundances drive the chances of individuals encountering and interacting with other species. However, our results suggest that frugivore bats are not functionally equivalent since contribution of species to network’s structure was associated with both cranial morphology and abundance.

Influencia de la morfología de los murciélagos en las propiedades estructurales de una red de frugívoros y plantas. La identificación de los factores que influencian la importancia de las especies para las interacciones mutualistas es crucial para diseñar estrategias de conservación y manejo destinadas a conservar la funcionalidad de los ecosistemas. A pesar de que los murciélagos son dispersores claves de semillas, los factores que influencian la importancia de estos para las propiedades estructurales de las redes de dispersión de semillas han sido poco estudiados. Evaluamos la influencia de la morfología craneal, el legado filogenético y la abundancia de murciélagos frugívoros sobre las propiedades estructurales de una red de interacción en un bosque seco tropical. Para esto, capturamos murciélagos e identificamos interacciones con plantas a través de las semillas colectadas en sus heces. Luego describimos la estructura de la red utilizando índices a nivel de red y evaluamos la contribución de murciélagos a la estructura de la red utilizando índices a nivel de especie. El análisis de la estructura de la red mutualista entre murciélagos frugívoros y planas indicó que: (1) hay pocas especies con alto número de interacciones, (2) la estructura fue más compartimentalizada y menos anidada de lo esperado, (3) hay subgrupos de murciélagos y plantas que están altamente conectadas entre ellas y (4) la red podría colapsar rápidamente debido a la pérdida de murciélagos con muchas interacciones (generalistas). Los murciélagos que más contribuyen a la estructura de la red tienden a presentar rostro corto y cráneo ancho y/o a ser abundantes, siendo Artibeus lituratus el murciélago con mayor importancia para la estructura de la red; sin embargo, la contribución a la estructura de la red no presentó señal filogenética. Según la hipótesis de neutralidad en interacciones mutualistas, la abundancia determina las posibilidades de que los individuos se encuentren e interactúen con otras especies. Sin embargo, nuestros resultados sugieren que los murciélagos frugívoros no son funcionalmente equivalentes para la estructura de la red, dado que la contribución de estos a la estructura de la red estuvo asociada tanto con la morfología craneal como con su abundancia.

Estudiamos la actividad reproductiva y dinámica poblacional de Rhipidomys fulviventer en un bosque andino de roble en la Cordillera Oriental de Colombia. Se realizó un seguimiento poblacional mensual de octubre de 2014 a septiembre de 2015 y de septiembre de 2016 a enero de 2018, mediante capturas en cinco estaciones fijas en un intervalo altitudinal de 2530 a 2657 m. La condición reproductiva en hembras se estableció por observación de características morfológicas externas y por el análisis de muestras de frotis vaginales para la determinación de la fase del ciclo estral, y en los machos se describió su actividad reproductiva mediante histología testicular. Así mismo se estimó la distribución, fluctuación y asociación del número de individuos capturados y la estructura etaria con la precipitación a lo largo del tiempo, así como la longevidad, la proporción de sexos y las probabilidades de supervivencia y recaptura utilizando el modelo Comarck-Jolly-Seber (CJS). En esta población de R. fulviventer las hembras tienen un patrón de poliestría no estacional sin presentar una relación entre la frecuencia de hembras reproductivas en cada estado y la variación del promedio mensual de lluvias; los machos adultos estuvieron activos reproductivamente, presentando espermatozoides todos los meses. Se encontró que el número de individuos capturados es variable sin relación con el régimen de lluvias, una supervivencia constante moderada-alta, una tasa de recaptura moderada, y diferencias entre machos y hembras en las tasas de recapturas, las áreas de actividad y las distancias medias recorridas, sugiriendo un sistema de apareamiento promiscuo.

Reproductive activity and population dynamics of Rhipidomys fulviventer (Rodentia: Cricetidae) in the Colombian eastern mountain range. We studied the reproductive activity and population dynamics of Rhipidomys fulviventer in an Andean oak forest in the Cordillera Oriental of Colombia. A monthly population follow-up was carried out from October 2014 to September 2015 and September 2016 to January 2018, through captures in five fixed stations in an altitudinal interval of 2530 to 2657 m. The reproductive condition in females was established by observation of external morphological characteristics and by the analysis of vaginal smear samples for the determination of the phase of the estrous cycle; in males, reproductive activity was described by testicular histology. Likewise, we estimated the distribution, fluctuation and association of number of individuals captured and age structure with precipitation over time, as well as longevity, sex ratio, and probabilities of survival and recapture using the Comarck-Jolly-Seber model (CJS). In this population of R. fulviventer, females have an unseasonal polyestrous pattern without showing a relation between the frequency of females in each reproductive stage and the variation of the monthly average of rains; adult males were reproductively active, showing sperm every month. It was found that the number of individuals captured is variable without relation to the rainfall regime, a moderate-high constant survival and recapture rate, and differences between males and females in recapture rates, areas of activity, and the average distances traveled, suggesting a promiscuous mating system.

The central portion of Brazil in Goiás state is mainly covered by Cerrado (Brazilian savanna). Its bat fauna is apparently diverse, but poorly known. In the present study, we inventoried bat species in three sites in the mid-northern region of Goiás, from 2009 to 2015. We used mist nets to capture bats, set up from sunset until four to six hours later, in a total sampling effort of 79,659 m²h. We captured 977 bats of 32 species and six families. Phyllostomidae was the predominant family in terms of abundance and richness. Carollia perspicillata was the most abundant species in all sites. The diversity profiles showed that only richness differed among sites, which supports that the three bat assemblages are structurally similar. However, the rarefaction curves showed similar richness among sites if removed differences of sample size. In general, the largest difference among communities was species composition, as species turnover was high. We recorded four new species for the state of Goiás; some of them are also new records for mid-western Brazil (P. personatus, L. silvicola, T. saurophila, and N. albiventris). The recorded richness in this study represents one third of the known species of bats in the whole Cerrado, including many cave species, which suggests that there might be several caves in São Patrício Valley.

Diversidade de morcegos em três áreas no Brasil Central. O Estado de Goiás localiza-se na região central do Brasil e coberto em quase toda sua extensão por vegetação do Cerrado (lato sensu). Neste estudo abordamos a estrutura da comunidade em três áreas na porção centro-norte de Goiás entre os anos de 2009 e 2015. Utilizamos a metodologia tradicional de capturas com redes de neblina armadas do crepúsculo vespertino a até quatro a seis horas após o escurecer e que totalizou um esforço amostral de 79 659 m²h. Capturamos 977 morcegos de 32 espécies de seis famílias. Houve predominância da família Phyllostomidae (abundância e riqueza). A espécie mais abundante nos três sítios foi Carollia perspicillata. A análise dos perfis de diversidade mostrou que a riqueza foi o único parâmetro que diferenciou as assembleias, reforçando que estruturalmente elas são muito parecidas em termos de diversidade. No entanto, quando aplicada a rarefação aos dados, observa-se que a riqueza se equivale quando anulado as diferenças no esforço amostral. A maior diferença na estruturação da comunidade foi a composição específica, tendo sido observado um alto turnover de espécies. Foram notificados quatro novos registros para o estado de Goiás, sendo alguns deles também inéditos para a região Centro-Oeste brasileira (P. personatus, L. silvicola, T. saurophila e N. albiventris). Observou-se um significativo número de espécies cavernícolas na amostragem, o que denota o potencial de ocorrência de cavidades naturais no vale do São Patrício. A riqueza observada no presente estudo representa 1/3 das espécies assinaladas para o bioma Cerrado.

The structure and composition of bat assemblages is mostly determined by features of the vegetation at local and landscape scales. We compared the bat assemblage present in a botanical garden with artificial lakes and exotic plant species to that of the surrounding native forest, which we expected to differ. Over a year of sampling revealed that both habitats possess a predominance of medium-sized frugivorous bats, but of different species. More insectivorous bats were captured in the garden. Despite limited differences in bat species composition, the structure of the two bat assemblages was noticeably different. These results indicate that bats respond differently to available habitats even on a small scale.

Comparação das assembléias de morcegos de um jardim botânico e da floresta nativa ao redor no sudeste do Brasil. A estrutura e composição das assembleias de morcegos é determinada principalmente por características de vegetação em escala local e de paisagem, assim, nós investigamos a assembleia de morcegos presentes em um jardim botânico com lagos artificiais e espécies de plantas exóticas e uma área de floresta nativa ao redor. Era nossa expectativa que as assembleias pudessem diferir. Durante um ano de  amostragem, ambos os habitats mostraram a predominância de frugívoros de tamanho médio, mas pertencentes a espécies diferentes; morcegos insetívoros foram mais capturados no jardim. Assembleias estruturalmente diferentes mostraram que os morcegos respondem diferentemente aos habitats disponíveis, mesmo em pequena escala.

El visón americano (Neovison vison) es el carnívoro exótico invasor de mayor distribución en Patagonia. Basados en relevamientos de campo y archivos históricos se presenta información detallada sobre su actual distribución en 180 km del Río Negro. Este foco representa la distribución más noreste, un nuevo ambiente invadido (Monte Oriental) y una nueva provincia con poblaciones silvestres (Buenos Aires). Documentamos la existencia de un criadero en las ciudades de Carmen de Patagones y Viedma (1965–1974), que podría ser el origen de este foco. Recomendamos diseñar e implementar planes de monitoreo y control de manera urgente.

American mink: a new invader of Rio Negro, Argentine Patagonia. American mink (Neovison vison) is the most widespread invasive carnivore in Patagonia. Based on field surveys and historical records, we present novel and detailed information of the American Mink present distribution along 180 km of the Río Negro. This invasion nucleus represents the most northeastern area recorded for the species, a new invaded ecoregion (Monte Oriental) and a new province with wild populations (Buenos Aires). We document the existence of a fur farm located in Carmen de Patagones and Viedma cities (1965–1974) that may have originated this focus. We recommend the prompt design and implementation of a control plan.

We provide the first systematic data on behavior and ecology of Aconaemys porteri. We used telemetry to monitor patterns of activity, resting locations, and range areas. Rock rat movements were statistically similar during nighttime and daytime, implying no clear diurnal or nocturnal activity. Animals used from 2 to 9 putative resting locations, but one was used more frequently. Rock rats showed relatively smaller range areas and low-to-moderate spatial overlap with neighbors, compared to other rodent species. These results indicate that A. porteri exhibits an intermediate level of sociality, compared to other octodontids.

Patrón de actividad y comportamiento social de Aconaemys porteri. Proporcionamos los primeros datos obtenidos de manera sistematizada sobre el comportamiento y la ecología de Aconaemys porteri. Utilizamos telemetría para monitorear los patrones de actividad, sitios de descanso o refugios, y ámbitos de hogar. Los movimientos de A. porteri tanto para las horas de oscuridad como de luz fueron estadísticamente similares, sugiriendo un patrón de actividad no estrictamente diurno o nocturno. Los animales utilizaron desde 2 hasta 9 sitios de descanso siendo uno de ellos utilizado con mayor frecuencia. Aconaemys porteri exhibió ámbitos de hogar relativamente pequeños y escaso a moderado solapamiento espacial entre individuos. Estos resultados sugieren que A. porteri presenta un nivel de sociabilidad intermedio, en comparación con otros octodóntidos.

Sergio A. Cardozo | Anatomía muscular del miembro anterior del gato montés (Leopardus geoffroyi): aspectos funcionales y filogenéticos en el contexto de Feliformia

M. Costamza Marchesi | Análisis de la morfología vertebral en asociación con las propiedades biomecánicas del esqueleto en cuatro especies de delfines del sur de Sudamérica, utilizando técnicas de morfometría geométrica

Jeronymo Dalapicolla | Integrative taxonomy of the genus Proechymis (Rodentia: Echimyidae) from western Amazon

Silvina F. Fabri | Análisis de potenciales corredores para los mamíferos nativos entre dos áreas protegidas de Argentina y Brasil a través de la Península de Andresito (Misiones – Argentina)