Keyword: biogeography

Carnivorans from Uruguay: updated distribution and changes through time

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Carnivorans are vital for ecosystem functioning and are one of the main groups used for conservation purposes. However, some species receive less attention than others. As many ecological aspects of South American carnivorans are unknown, the distribution range becomes of primary importance for conservation use. We aimed to analyze the distribution of terrestrial carnivorans in Uruguay, yielding an updated database and including a temporal dimension of distribution changes. We searched the main collections of mammals and bibliographic references for carnivorans in Uruguay. We divided the records according to temporal provenance and analyzed the changes in knowledge of distributions according to time. We also analyzed species and family richness for actual times with a 25 × 25 km grid. Finally, we studied the possible bias in data gathering related to roads. We ensembled the most complete database for carnivoran distribution in Uruguay, with 1905 records. The country had a total species richness of 16, varying with time according to local extinctions and new records of different species. The most common species was Cerdocyon thous, while the least recorded was Nasua nasua. The jaguar Panthera onca has been extinct since historical times, while Pteronura brasiliensis has probably been extinct since actual times. The areas with higher species richness were located in the northeastern, south, and southeastern parts of the country. A bias in data gathering was present, marked by the proximity to roads. Finally, protected areas in Uruguay showed a different proportion of protected species, regardless of their surface.

Carnívoros de Uruguay: distribución actualizada y cambios a través del tiempo. Los carnívoros son vitales para el funcionamiento de los ecosistemas, y son uno de los grupos más usados para los objetivos de conservación. Sin embargo, muchas especies reciben más atención que otras. Como existen diversos aspectos ecológicos de carnívoros sudamericanos que se desconocen, los rangos de distribución son esenciales para las categorizaciones de conservación. Analizamos la distribución de los carnívoros terrestres en Uruguay para generar la base de datos más actualizada a la fecha, y estudiar los cambios temporales. Se relevaron especímenes de colecciones biológicas y referencias bibliográficas. Se dividieron los registros acorde a su proveniencia temporal y se analizaron los cambios en su distribución. Además, se analizó la riqueza de especies y familias, con una grilla de 25 × 25 km. Finalmente, se estudió el posible sesgo en la colecta de datos acorde a la cercanía de rutas. Se generó la base de datos más completa a la fecha, con 1905 registros. Uruguay tuvo una riqueza específica de 16, que ha variado, según el tiempo,con extinciones y nuevos registros. La especie más registrada fue Cerdoyon thous, mientras que la menos registrada fue Nasua nasua. El jaguar Panthera onca se encuentra extinto desde tiempos históricos, mientras que Pteronura brasiliensis se encuentra posiblemente extinta desde tiempos actuales. Las áreas con mayor riqueza se encontraron en las partes noreste, sur y sureste del país. Se encontró un sesgo en los datos, marcado por la cercanía a las rutas. Finalmente, las áreas protegidas mostraron una diferente proporción de especies protegidas, independientemente de su superficie.

Graphical abstract for the article “Carnivorans from Uruguay: updated distribution and changes through time” (Schiaffini et al., 2023)

Redescripción de Eremoryzomys polius (Rodentia: Cricetidae) y descripción de una nueva especie del género Eremoryzomys

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Eremoryzomys polius (Osgood 1913) es un roedor orizomyino endémico de la cuenca alta del río Marañón, Perú, del que solo se conocen 15 ejemplares procedentes de 7 localidades y que no había sido registrado en los últimos 22 años. En este trabajo se reportan 4 localidades nuevas para E. polius, que expanden la distribución de este roedor. Adicionalmente, describimos una especie nueva para el género Eremoryzomys en base a la comparación de caracteres morfológicos cualitativos y cuantitativos con E. polius. La especie nueva de Eremoryzomys se diferencia de E. polius en los siguientes rasgos: cola corta ligeramente bicoloreada; almohadillas de las patas posteriores oscuras; almohadillas tenar e hipotenar casi contiguas; cráneo más pequeño, con un rostro corto y grácil; cresta nucal desarrollada; forámenes incisivos que llegan hasta el anterocono del M1, serie molar más corta y proceso coronoides triangular. La nueva especie es endémica de los bosques premontanos del Amazonas de la cuenca media del río Marañón, agregando evidencia de la importancia de esta región como centro de endemismo y de la necesidad de su conservación. Finalmente, sugerimos que E. polius, en su actual concepción, es aún un complejo de especies.

Redescription of Eremoryzomys polius (Rodentia: Cricetidae) and description of a new species of the genus Eremoryzomys. Eremoryzomys polius (Osgood 1913) is an oryzomyine rodent endemic to the upper basin of the Marañón River in Peru, known from only 15 specimens at 7 localities and with no new records in at least 22 years. Here we report an expansion of the geographic distribution of E. polius by confirming its presence at four new locations near the Marañón River. In addition, we describe a new species of Eremoryzomys based on comparison of its morphological and morphometric characteristics with E. polius. The new species of Eremoryzomys differs from E. polius in the following traits: slightly bicolored and short tail; dark hind leg pads; thenar and hypothenar pads nearly contiguous; small skull with a short and gracile rostrum; well-developed nuchal ridge; short incisive foramen reaching the anterocone of M1; shorter molar series and triangular coronoid process. This new species is endemic to premontane Amazon forest of the middle basin of the Marañon River, adding support for the importance of this region as a center of endemism and as a focus for habitat conservation. Finally, we suggest that E. polius, as currently understood, remains a species complex.

New records of Monodelphis kunsi (Didelphimorphia, Didelphidae) from Brazil

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We review the known distribution of Monodelphis kunsi from South America and reported nine new localities of occurrence in Mato Grosso do Sul state, southwestern Brazil. These new records fill the gap on geographic distribution of M. kunsi in southwestern Brazil. The species presents wide geographic range including distinct habitats. The lack of studies in southwestern Brazil and the non-utilization of pitfall traps can be the main factors responsible for the lack of knowledge on distribution of small mammal species to this region.

Novos registros de Monodelphis kunsi (Didelphimorphia, Didelphidae) para o Brasil. Nos revisamos o conhecimento da distribuição de Monodelphis kunsi para América do Sul e informamos nove localidades de ocorrência no Estado de Mato Grosso do Sul, sudoeste do Brasil. Estes novos registros cobrem uma lacuna na distribuição de M. kunsi no sudoeste do Brasil. Os espécimes apresentaram ampla distribuição geográfica incluindo diferentes habitas. A falta de estudos no sudoeste do Brasil e a não utilização de armadilhas pitfall podem ser os principais fatores responsáveis pela falta de conhecimento na distribuição das espécies de pequenos mamíferos para esta região.

Fossil evidence and probable extinction of the greater fishing bat Noctilio leporinus (Chiroptera: Noctilionidae) on Isla de Mona, Puerto Rico

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The greater fishing bat Noctilio leporinus has long been erroneously attributed to Isla de Mona, Puerto Rico, based on specimens from Monos Island, Trinidad. There are no historical specimens from the island, but a radius from a late Holocene cave deposit now establishes that the species was once present. Its apparent extinction may be have been caused by human intervention, a factor that should be taken into account in the biogeography of West Indian bats.

Evidencia fósil y probable extinción del murciélago pescador Noctilio leporinus (Chiroptera: Noctilionidae) en Isla de Mona, Puerto Rico. Durante mucho tiempo el murciélago pescador Noctilio leporinus ha sido atribuído erróneamente a Isla de Mona, Puerto Rico, basándose en unos especímenes de la Isla de Monos, Trinidad. No hay especímenes históricos procedentes de la isla pero un radio obtenido de unos depósitos holocénicos de una cueva ahora establecen que la especie estuvo presente. Su aparente extinción pudo deberse a la intervención humana, un factor que debe ser tomado en consideración en la biogeografía de los murciélagos de las Indias Occidentales.

Mammals of the Cosigüina Peninsula of Nicaragua

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Nicaragua’s Cosigüina Peninsula, located at the northwestern tip of the country, is one of the most poorly studied biotic regions in Central America. The peninsula has been
occupied for millennia because the climate of the region supported human habitation and because of its strategic position along the rich Pacific coast. The combination of long-term occupancy by humans and the cataclysmic eruptions of Volcán Cosigüina have produced a heavily impacted landscape. During the 1960s, the University of Kansas conducted multiyear field surveys of the terrestrial mammals on the peninsula and the adjacent mainland to quantify species diversity, relationships, abundances, habitat use, and reproduction. The mammalian fauna of the peninsula contains at least 39 species of terrestrial mammals, which includes 7 orders and 17 families. These include Didelphimorphia (2 species)—Didelphidae, 2; Chiroptera (22)—Emballonuridae, 2; Noctilionidae, 1; Mormoopidae, 1; Phyllostomidae, 12; Vespertilionidae, 3; Molossidae, 3; Carnivora (4)—Procyonidae, 1; Mustelidae, 1; Felidae, 2; Perissodactyla (1)—Tapiridae, 1; Artiodactyla (1)—Cervidae, 1; Rodentia (8)—Sciuridae, 1; Heteromyidae, 1; Muridae, 5; Dasyproctidae, 1; Lagomorpha (1)—Leporidae, 1. We provide new information on distributions, systematics, morphometrics, and natural history of the species of terrestrial mammals on the Cosigüina Peninsula, including a number of new records for the peninsula. We document that diversity and abundances of mammals can be substantial in a heavily impacted landscape. In comparison with five other mammalian faunas in Nicaragua, the Cosigüina fauna is most similar in size and diversity with those from elsewhere in the Pacific lowlands. The fauna from the Cordillera los Maribios, which is composed of the volcanic peaks along the eastern edge of the Pacific Lowlands, has the lowest number of species recorded for any of the six faunas with only 21 species recorded; however, this fauna may be under sampled or the unstable environments offered by these active volcanoes may not support a large or diverse mammalian fauna. The mammalian faunas from the remaining two physiographic regions of Nicaragua—Central Highlands and Atlantic Lowlands—have larger, more diverse faunas than that of the Cosigüina Peninsula and elsewhere in the Pacific lowlands. Three reserves in Nicaragua’s Sistema Nacional de Áreas Protegidas now protect more than one fourth of the peninsula.

Micromamíferos (Didelphimorphia y Rodentia) del sudoeste de la provincia de Buenos Aires (Argentina): taxonomía y distribución

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Small mammals (Didelphimorphia and Rodentia) from southwestern Buenos Aires Province, Argentina: taxonomy and distribution. Species of small mammals from southwestern Buenos Aires Province range within a wide variety of habitats: herbaceous (Pampean District), shrubs (Monte District), steppes, and xerophytic woodlands (Espinal District). Their natural history is still poorly known. In this paper we make a synthesis of the taxonomy and distribution of the marsupials (Marmosinae) and rodents (Sigmodontinae) of southwestern Buenos Aires Province. Distributional records and taxonomical information were obtained from field survey, analyses of raptor pellets, revision of specimens housed in collections in Argentina, and literature. Between Sierra de la Ventana (38° S) and the Río Negro (41° S) occur two species of marmosines and 14 of sigmodontine rodents. Some of these species show a restricted distribution (e.g., Phyllotis xanthopygus, endemic for Sierra de la Ventana), and others are widespread (e.g. Akodon azarae or Calomys musculinus) across different phytogeographic units. A cluster analysis at local scale shows an ordination of small mammal assemblages with the topology (Sierra de la Ventana + Southern Atlantic Coast) (Espinal + Monte). The zoogeographic unicity of the Monte in the study area is evidenced by two sigmodontines, Akodon iniscatus and Oligoryzomys longicaudatus. The micromammal assemblage of Sierra de la Ventana may be characterized as pampasic. The wide distribution of A. azarae and C. musculinus may reflect the anthropic activities developed during the last century. These activities on shrub steppe have certainly diluted the original zoogeographic boundaries and allowed the dispersion of opportunistic sigmodontine species.

Distribution of Pseudoryzomys simplex (Rodentia: Cricetidae) in Argentina

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We report new records for the poorly known sigmodontine rodent Pseudoryzomys simplex in Argentina, totalizing 28 recording localities (Formosa, Chaco, and Santa Fe provinces). The southern limit of the species is about 30° S and its distribution, in Argentina, is mainly restricted to the Eastern Chaco biome.

Distribución de Pseudoryzomys simplex (Rodentia: Sigmodontinae) en la Argentina. Se presentan nuevos registros para el roedor sigmodontino Pseudoryzomys simplex en Argentina, totalizando 28 localidades conocidas (provincias de Formosa, Chaco y Santa Fe). El límite sur de la especie se encontraría hacia los 30° S y su distribución, en Argentina, se restringe principalmente al Chaco oriental.

Nuevos datos sobre la distribución de Irenomys tarsalis (Philippi, 1900) (Rodentia: Sigmodontinae) en la Argentina

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Se brinda una síntesis de las localidades conocidas en Argentina para el roedor sigmodontino Irenomys tarsalis, adicionando los registros más extremos hacia el norte (Pilolil, 39° 38′ 60″ S, 70° 57′ 00″ O, Catán Lil, Neuquén) y hacia el sur (44° 49′ 25″ S, 72° 00′ 26″ O, Río Senguerr, Chubut).

New data on the geographic distribution of Irenomys tarsalis (Philippi, 1900) (Rodentia: Sigmodontinae) in Argentina. We summarize the known Argentinean localities for this sigmodontine, adding the northernmost (Pilolil, 39° 38′ 60″ S, 70° 57′ 00″ W, Catán Lil, Neuquén) and southernmost (44° 49′ 25″ S, 72° 00′ 26″ W, Río Senguerr, Chubut) records.

Resúmenes de tesis

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Alexandra M. Ramos Bezerra | Variabilidade morfológica e status taxonômico das amostras populacionais do gênero Clyomys (Rodentia: Echimyidae) / Morphologic variability and taxonomic status of population samples of the Clyomys genus (Rodentia: Echimyidae)

Guillermo D’Elía | Testing patterns and processes of diversification of a South American group of land mammals (Rodentia, Cricetidae, Sigmodontinae)

Patricia Avello Nicola | Evolução craniana em Trinomys yonenagae (Rodentia: Echimyidae): análise geométrica no contexto de uma filogenia molecular / Evolution of skull in Trinomys yonenagae (Rodentia: Echimyidae): Geometric analysis in the context of a molecular phylogeny

Richard D. Stevens | Taxonomic, functional, and phenetic components of biodiversity: Perspectives on the community ecology of New World bats