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Overall morphological similarity between the armored rat (Hoplomys gymnurus) and the spiny rats, especially the Tome’s spiny rat (Proechimys semispinosus), has been noticed before, but this similarity has yet to be quantified. Here, we used 35 morphometric measurements from the skull of H. gymnurus and other echimyid species (including P. semispinosus) to quantify this similarity. Discriminant function analysis revealed marked similarities between armored and spiny rats. Our results are consistent with previous morphological and molecular analyses, where the proximity of these two genera was suggested. Given the new morphological evidence, we propose that these two genera should be synonymized; this taxonomic change would revalidate the name Proechimys gymnurus.

Los géneros Hoplomys y Proechimys (Rodentia: Echimyidae) sinonimizados. La similitud morfológica general entre la rata acorazada (Hoplomys gymnurus) y las ratas espinosas, especialmente la rata espinosa de Tome (Proechimys semispinosus), se ha observado antes, pero esta similitud aún no se ha cuantificado. Aquí utilizamos 35 medidas morfométricas del cráneo de H. gymnurus y otras especies de equímidos (incluido P. semispinosus) para cuantificar esta similitud. El análisis de la función discriminante reveló marcadas similitudes entre ratas con armadura y espinosas. Nuestros resultados son coincidentes con análisis morfológicos y moleculares previos, donde se sugirió la proximidad de estos dos géneros. Dada la nueva evidencia morfológica, proponemos que estos dos géneros sean sinonimizados; este cambio taxonómico revalidaría el nombre Proechimys gymnurus.

Subterranean rodents are key ecosystem engineers whose burrowing activity modifies soil structure and vegetation. In this study, we used ground-penetrating radar (GPR) to non-invasively assess the bioturbation footprint of Ctenomys mendocinus in the southernmost portion of the Puna ecoregion, the Desert Puna (Argentina). Our objectives were to (1) determine the maximum depth of burrows, (2) quantify the proportion of soil affected by the rodent’s activity, and (3) detect possible legacy burrow structures in areas without visible surface signs. Seven 15 × 50 m grids (750 m² each) were surveyed with GPR, five showing surface activity and two without it. The radar detected tunnel-like anomalies at all sites, with most disturbance concentrated between 10 and 20 cm in deep. Maximum burrow depth reached 0.75 m. In areas lacking surface mounds or openings, subsurface hyperbolic reflections indicated the presence of historical burrows. These results demonstrate that surface observations underestimate the true extent of bioturbation and that C. mendocinus leaves a lasting legacy belowground. Our findings highlight the value of GPR in detecting both past and present fossorial activity and in assessing the ecological influence of subterranean rodents in arid mountain environments.

Revelando la bioturbación de un roedor herbívoro subterráneo en un desierto frío de gran altitud mediante radar de penetración terrestre. Los roedores subterráneos son ingenieros ecosistémicos clave, cuya actividad de excavación modifica la estructura del suelo y la vegetación. En este estudio utilizamos un radar de penetración terrestre (GPR) para evaluar de forma no invasiva la huella de bioturbación de Ctenomys mendocinus en el extremo sur de la ecorregión Puna, la Puna Desértica (Argentina). Nuestros objetivos fueron: (1) determinar la profundidad máxima de las cuevas, (2) cuantificar la proporción de suelo afectado por la actividad del roedor, y (3) detectar posibles estructuras de madrigueras antiguas en áreas sin signos superficiales actuales visibles. Se relevaron siete grillas de 15 × 50 m (750 m² c/u), con GPR, cinco con actividad superficial visible y dos sin ella. El radar detectó anomalías similares a túneles en todos los sitios, con la mayor actividad entre los 10 y 20 cm de profundidad. La profundidad máxima registrada fue de 0,75 m. En áreas sin montículos ni bocas visibles, las reflexiones hiperbólicas subsuperficiales indicaron la existencia de madrigueras históricas. Estos resultados demuestran que la observación superficial subestima la verdadera extensión de la bioturbación y que C. mendocinus deja un legado persistente en el subsuelo. Nuestros hallazgos resaltan el valor del GPR para detectar actividad fosorial pasada y presente, y para evaluar la influencia ecológica de roedores subterráneos en ambientes montañosos áridos.

In this study, we investigated the population dynamics and reproductive patterns of Monodelphis domestica in an urban forest fragment on São Luís Island, Maranhão, Brazil. The data were collected using capture-recapture techniques with Sherman® traps. The age classification and reproductive status of the females were determined based on an analysis of their external morphological characteristics. The relationship between the incidence of reproductive females and environmental variables (precipitation and day length) was analyzed using logistic regression models. The results demonstrated a high recapture ratio and evidence of reproduction throughout the year, peaking in April, May, and June. The occurrence of juveniles overlapped with adults, contributing to the renewal of the population. The reproductive behavior of M. domestica varies and may be influenced by the accessibility of food resources and contact with male pheromones. This finding suggests that urban forest fragments play a crucial role in the conservation of this species.

Ecologia reprodutiva de uma espécie de marsupial em fragmento urbano da Amazônia Oriental. Este estudo investigou a dinâmica populacional e os padrões reprodutivos de Monodelphis domestica em um fragmento florestal urbano na Ilha de São Luís, Maranhão, Brasil. As coletas foram baseadas em dados de captura-recaptura, utilizando armadilhas Sherman®. A classificação etária e o estado reprodutivo das fêmeas foram determinados com base em características morfológicas externas. A relação entre a incidência de fêmeas reprodutivas e variáveis ambientais (precipitação e fotoperíodo) foi analisada por meio de modelos de regressão logística. Os resultados demonstram indícios de alta porcentagem de recaptura, bem como uma reprodução ao longo de quase todo o ano, com picos em abril, maio e junho, com indivíduos juvenis apresentando uma certa sobreposição em relação aos adultos e compondo a renovação da mesma população. O comportamento reprodutivo de M. domestica apresenta uma variabilidade que pode ser influenciada pela acessibilidade dos recursos alimentares e pelo contato com os feromônios masculinos. Este fato sugere que os fragmentos florestais urbanos desempenham um papel crucial na conservação da espécie.

Biological material stored in Natural History Collections (NHCs) represents a key source of data for genetic studies, although specimen age (year of collection) and preservation methods may affect DNA integrity. We investigated microsatellite genotyping success of DNA isolated from 265 soft (skin) and hard (bone) samples of puma Puma concolor and Pampas fox Lycalopex gymnocercus specimens (collected between 1905 and 2022) from Argentinean NHCs. Overall, 43.8% of the samples were successfully genotyped, with significantly higher success for those collected after 1989 than up until the same year (62.8% vs. 17.9%). When comparing sample types, skin exhibited a significantly higher success rate than bone samples (51.8% vs. 37.8%). Limited to the Pampas fox, we found no significant differences in DNA concentration between genotyped and non-genotyped samples, while a slight negative correlation was observed between DNA concentration and sample age. We report simple and efficient sampling protocols, which could be widely applied for future studies based on biological material from NHCs. The advantages of skin sampling are twofold: it is only minimally affecting specimen integrity, especially for medium- to large sized carnivore mammal species, and it offers a suitable source of DNA from specimens hosted within collections for less than 30 years. However, the bone sampling approach we propose may provide a more reliable source of DNA for older specimens.

¿Piel o hueso? Evaluación del éxito de genotipado de microsatélites en muestras de Puma concolor y Lycalopex gymnocercus procedentes de colecciones de historia natural de Argentina. El material biológico depositado en Colecciones de Historia Natural (CHN) constituye una fuente invalorable de datos para estudios genéticos, a pesar de que la antigüedad de los especímenes (año de colecta) y los métodos de preservación pueden afectar la integridad del ADN. Investigamos el éxito de genotipado de microsatélites a partir de ADN aislado de 265 muestras (cueros y huesos) de puma (Puma concolor) y zorro pampeano (Lycalopex gymnocercus), colectados entre 1905 y 2022 en CHN de Argentina. En conjunto, el 43,8% de las muestras fueron genotipadas, con un éxito significativamente mayor en aquellas colectadas a partir de 1990, en comparación con las obtenidas antes de ese año (62,8% vs. 17,9%). Al comparar los tipos de muestra, los cueros mostraron un éxito significativamente superior al de los huesos (51,8% vs. 37,8%). En el caso del zorro, no se encontraron diferencias significativas en la concentración de ADN entre las muestras genotipadas y no genotipadas, aunque se observó una leve correlación negativa entre la concentración de ADN y la antigüedad de la muestra. En este trabajo presentamos protocolos de muestreo simples y eficientes, que pueden aplicarse en futuros estudios basados en material biológico de CHN. Entre las ventajas del muestreo de cueros, se puede mencionar que este afecta mínimamente la integridad del espécimen —especialmente en mamíferos carnívoros de tamaño mediano a grande— y ofrece una fuente adecuada de ADN en ejemplares alojados en colecciones por menos de 30 años. Por otra parte, el método de muestreo óseo que proponemos constituiría una fuente más confiable de ADN en especímenes antiguos.

Between October 11 and 16, 2019, and March 12 and 14, 2022, nine flights were made along the coast of the province of Buenos Aires, Argentina, in meteorological conditions that allowed the sighting of several species of cetaceans. The two series of surveys (2019–2022) were carried out separately due to travel restrictions associated with the COVID-19 pandemic. We report the estimates of abundance for Franciscana dolphins (Pontoporia blainvillei). The number of sightings (and individuals) in 2019 and 2022 was 41 (68) and 55 (80), respectively. Abundance for FMA IVb was estimated to be 11,070, while for FMA IVc was 3,309. The total abundance of Franciscana for both areas would give a figure of 14,379 dolphins. Considering this estimation obtained in 2022, plus the 5,896 dolphins estimated in 2004 for the southern area, gives us a sum of 20,275 individuals without considering those in deeper waters beyond the 30 m isobath. Even though the comparisons with previous estimates (2003–2004) must be done cautiously, we did not detect a decreasing trend in the abundance of this species in the studied area. Considering an extrapolated abundance of 5,894 individuals for the Bahía Samborombón (area not flown), Argentine waters would have a figure around 26,169 individuals. This figure considers abundance only from the coast to the 30 m isobath. Considering this abundance, the mortality rates estimated to date for Argentine waters are less than the 2% established by the IWC as a risk to the population.

Estimación de la abundancia del delfín franciscana mediante censos aéreos en la provincia de Buenos Aires, Argentina, con comentarios sobre las tasas de mortalidad. Entre el 11 y el 16 de octubre de 2019 y entre el 12 y el 14 de marzo de 2022 se realizaron nueve vuelos a lo largo de la costa de la provincia de Buenos Aires, Argentina, bajo condiciones meteorológicas favorables para el avistamiento de cetáceos. Las dos series de censos (2019–2022) se realizaron por separado debido a las restricciones impuestas por la pandemia de COVID-19. Se presentan las estimaciones de abundancia para el delfín Franciscana (Pontoporia blainvillei). El número de avistamientos (e individuos) fue de 41 (68) en 2019 y de 55 (80) en 2022. La abundancia estimada fue de 11.070 individuos para la FMA IVb y de 3.309 para la FMA IVc. En conjunto, ambas áreas suman 14.379 delfines. Si se agregaran los 5.896 individuos estimados en 2004 para el área sur, el total alcanzaría 20.275, sin considerar los ejemplares que habitan aguas más profundas, más allá de la isobata de 30 m. Si bien las comparaciones con estimaciones previas (2003–2004) deben realizarse con cautela, no se detectó una tendencia decreciente en la abundancia en el área estudiada. Si se consideran los 5.894 individuos que se obtienen de la extrapolación para la Bahía Samborombón (área no sobrevolada), en aguas argentinas habría aproximadamente 26.169 individuos entre la costa y la isobata de 30 m. Con esta abundancia, las tasas de mortalidad estimadas para Argentina serían inferiores al 2% establecido por la CBI como umbral de riesgo poblacional.

The analysis of δ¹³C and δ¹⁵N values in collagen obtained from the Lama guanicoe modern and archaeological bones (N = 26) from the Sarmiento Basin area (Colhué Huapi and Musters lakes, central Patagonia) indicates a diet based on C₃ plants (Calvin–Benson photosynthetic carbon fixation cycle). Within this group of plants, a marked increase in grass consumption during the recent lapse (post-1,500 years BP) is recorded. In contrast, a strong signal of higher woody plant consumption is recorded between 3,844–1,920 years BP (i.e., shrubs) and among modern individuals (i.e., subshrubs). It is proposed that when the valley floors of the Colhué Huapi and Musters lakes were exposed (post-1,500 years BP), there was greater availability of wetlands and grasslands.

Dieta y uso del hábitat del guanaco (Lama guanicoe) en el pasado y en la actualidad en los lagos Colhué Huapi y Musters (Patagonia, Argentina), a partir del análisis de isótopos estables de carbono y nitrógeno del colágeno óseo. El análisis de los valores de δ¹³C y δ¹⁵N obtenidos de colágeno de huesos modernos y arqueológicos de Lama guanicoe (N = 26) de los lagos Colhué Huapi y Musters en el área de la Cuenca de Sarmiento (Patagonia central) indica una dieta basada en plantas C₃ (ciclo de fijación fotosintética del carbono de Calvin–Benson). Dentro de este grupo de plantas, se observa un marcado incremento en el consumo de gramíneas durante el lapso reciente (posterior a 1.500 años AP). En contraste, se registra un mayor consumo de plantas leñosas entre 3.844–1.920 años AP (i.e., arbustos) y entre los individuos modernos (i.e., subarbustos). Se propone que cuando los fondos de los valles de los lagos Colhué Huapi y Musters quedaron expuestos (posterior a 1.500 años AP) hubo una mayor disponibilidad de humedales y pastizales.

La evaluación de la dieta de mesocarnívoros generalistas es esencial para comprender su papel ecológico y su capacidad de adaptación en ambientes heterogéneos. En este estudio se caracterizó la variación de la dieta de la zorra gris (Urocyon cinereoargenteus) a través del análisis y registro de heces en tres tipos de cobertura vegetal (bosque de encino, vegetación riparia y zona antropizada) en Santiago Ixtaltepec, Asunción Nochixtlán, Oaxaca, México, durante las temporadas climáticas de lluvias y sequía. Se colectaron y analizaron 247 heces, y se identificaron 14 componentes alimenticios agrupados en cinco categorías. La dieta estuvo dominada por frutos, con la mayor frecuencia de ocurrencia (59,52%), particularmente Juniperus sp., seguida por insectos (31,57%), principalmente ortópteros y coleópteros. Aves, mamíferos y quilópodos tuvieron un porcentaje de representación menor. Se registra por primera vez en Oaxaca el consumo de los frutos de Juniperus sp., Quercus sp., Prunus sp., larvas Phyllophaga sp. y del roedor Reithrodontomys sp. El índice de Shannon y la amplitud de nicho de Levins indicaron mayor diversidad y amplitud trófica en la temporada de lluvias que en la de sequía, lo que refleja la disponibilidad estacional de recursos. Los resultados evidencian la plasticidad trófica de U. cinereoargenteus y su papel en la dispersión de semillas y control de invertebrados, y resalta la importancia de conservar la heterogeneidad del paisaje para mantener la funcionalidad ecológica de la especie.

Spatial and temporal variation of the diet of the gray fox (Urocyon cinereoargenteus: Carnivora, Canidae) in Ssantiago Ixtaltepec, Asunción Nochixtlán, Oaxaca, Mexico. Evaluating the diet of generalist mesocarnivores is essential to understanding their ecological role and adaptive capacity within heterogeneous environments. This study characterized the dietary variation of the gray fox (Urocyon cinereoargenteus) through the analysis of fecal samples across three land-cover types (oak forest, riparian vegetation, and anthropized area) in Santiago Ixtaltepec, Asunción Nochixtlán, Oaxaca, Mexico, during the rainy and dry seasons. A total of 247 scats were collected and analyzed, identifying 14 food items classiffied into five categories. The diet was predominantly frugivorous, showing the highest frequency of occurrence (59.52%), particularly Juniperus sp., followed by insects (31.57%), primarily orthopterans and coleopterans. Birds, mammals, and chilopods represented a minor portion of the diet. This study provides the first record in Oaxaca of the consumption of the fruits of Juniperus sp., Quercus sp., Prunus sp., Phyllophaga sp. larvae, and the rodent Reithrodontomys sp. The Shannon’s diversity index and Levins’s niche breadth indicated greater trophic diversity and niche breadth during the rainy season compared to the dry season, reflecting the seasonal resource availability. These results demonstrate the trophic plasticity of U. cinereoargenteus and its role in seed dispersal and invertebrate control, highlighting the importance of preserving landscape heterogeneity to maintain the ecological functionality of the species.

The brown-nosed coati (Nasua nasua) is a Procyonid mesocarnivore commonly found coexisting with people in Brazilian urban forest fragments. Here, we aimed to assess the diet of brown-nosed coatis in two urban forest fragments of Campo Grande, MS: Parque Estadual do Prosa (PEP), a protected area, and Air Force Village (AFV), an urbanized area with physical barriers such as walls and fences. The diet was analyzed based on feces of brown-nosed coatis captured in wire traps during campaigns conducted from March to November 2018, January to April 2019, and March to June 2020 (only PEP), with 10 consecutive days per monthly campaign. Once captured, animals were sedated and identified, and fecal samples were collected and analyzed macrocospically and microscopically. In total, 190 coatis were sampled (including 115 females, 65 males, and 10 unidentified individuals), with some individuals being recaptured during the study period, and a total of 510 items were identified across both areas, with PEP showing 238 items (average of 2.4 items/fecal sample) and AFV showing 272 items (average of 3.8 items/fecal sample). In PEP, the diet of the coatis consisted mainly of invertebrates (57.6%), with human-derived food residues (HDFR), such as paper and string, representing 7.1% of the diet. In AFV, invertebrates dominated the diet (98.6%), with HDFR comprising 12.9% of the diet. Therefore, HDFR was present in the diet of brown-nosed coatis in both studied areas, with AFV showing nearly double the percentage compared to PEP. This study highlights that in urban environments, the diet of these animals can include HDFR, although their diet is still dominated by natural food resources. It remains to find out the impact that such intake of HDFR (nearly 3% of the diet based on Po) can have on the health of N. nasua individuals inhabiting urban environments.

O que quatis (Nasua nasua) comem em uma floresta de concreto no centro-oeste brasileiro? O quati (Nasua nasua) é um mesocarnívoro Procyonidae, comumente encontrado coexistindo com pessoas em fragmentos florestais urbanos brasileiros. Aqui, temos como objetivo acessar a dieta de quati em dois fragmentos florestais urbanos de Campo Grande, MS: Parque Estadual do Prosa (PEP), uma área protegida, e Vila da Base Aérea (AFV), uma área urbanizada com barreiras físicas como muros e cercas. A dieta foi analisada com base nas fezes de quatis capturados em gaiolas durante as campanhas conduzidas de março a novembro de 2018, de janeiro a abril de 2019 e de março a junho de 2020 (apenas no PEP), com 10 dias consecutivos por mês por campanha. Uma vez capturados, os animais foram sedados, identificados e amostras de fezes foram coletadas e analisadas macro e microscopicamente. No total, 190 quatis foram amostrados (incluindo 115 fêmeas, 65 machos e 10 indivíduos não identificados), com alguns indivíduos sendo recapturados durante o período de estudo e um total de 510 itens identificados entre as duas áreas, com PEP tendo 238 itens (média de 2,4 itens/amostra fecal) e AFV com 272 (média de 3,8 itens/amostra fecal). No PEP, a dieta dos quatis consistiu principalmente de frutas (91,4%), com resíduos derivados de comida humana (HDFR), como papel e barbante, representando 2,94% da dieta. Na AFV, frutas dominaram a dieta (94,4%), com HDFR consistindo em 3,3% da dieta. Então há a presença de resíduos relacionados com comida humana na dieta dos quatis nas duas áreas, sendo AFV com quase o dobro de porcentagem de itens comparado ao PEP. Esse estudo ressaltou que a dieta desses animais em ambiente urbano e a habilidade de utilizar recursos disponíveis em áreas habitadas por humanos.

Las áreas protegidas juegan un papel clave para contrarrestar las amenazas que enfrenta la biodiversidad. Sin embargo, algunas están pobremente implementadas, no existe suficiente conocimiento básico sobre las especies que conservan ni de las presiones que las afectan. La Reserva Provincial Las Lancitas es un área protegida clave en el corredor ecológico Parque Nacional Calilegua – Parque Nacional El Rey – Reserva Nacional Pizarro. Hasta el momento no se han realizado estudios detallados, sistemáticos y cuantitativos que permitan contar con información de base sobre el ensamble de mamíferos medianos y grandes en esta área protegida. Los objetivos de este trabajo son establecer una línea de base de la composición de especies y determinar el uso de hábitat de las especies de mamíferos nativos y domésticos más frecuentes. Para ello se colocaron 20 cámaras trampa y se utilizaron modelos de ocupación, entre los que se incluyen covariables ambientales y antrópicas para determinar la composición y el uso de hábitat de las especies de mamíferos. En un total de 600 noches/cámara se registraron 25 especies de mamíferos medianos y grandes: 21 especies nativas y cuatro especies domésticas. Se destaca una elevada riqueza de especies nativas registradas y una alta frecuencia de registros de especies domésticas. Si bien la ganadería está permitida desde la creación de la Reserva debido a la presencia de familias ganaderas, no existe un plan de manejo ganadero que minimice los impactos negativos sobre la biodiversidad y asegure un uso sustentable del bosque.

Composition of the assemblage and use of the habitat of medium and large mammals in the Las Lancitas Provincial Nature Reserve, province of Jujuy, Argentina. Protected areas play a key role in counteracting threats to biodiversity. However, some protected areas are poorly implemented, and there is a lack of sufficient baseline knowledge regarding the species they conserve or the pressures affecting them. The Reserva Provincial Las Lancitas is a crucial protected area in the Parque Nacional Calilegua – Parque Nacional El Rey – Reserva Nacional Pizarro ecological corridor. To date, no detailed, systematic, and quantitative studies have been conducted to provide baseline information on the assemblage of medium and large mammals in this protected area. The objectives of this study are to establish a baseline on the composition of species and to determine the habitat use for the most frequent native and domestic mammal species. To this end, 20 camera traps were set up and occupancy models including environmental and anthropic covariates were used to determine the composition and habitat use of mammal species. A total of 25 medium and large mammal species were recorded over 600 camera-nights: 21 native species and four domestic species. Of particular note is the high richness of native species recorded and the high frequency of domestic species records. Although livestock ranching has been permitted since the inception of the reserve due to the presence of ranching families, there is no livestock management plan in place to minimize negative impacts on biodiversity and ensure a sustainable use of the forest.