Volumen y Número: Vol. 30

Influence of interference competition and seasonality on the activity patterns of carnivorous mammals in the Brazilian Cerrado

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The pattern of activity of species can be influenced by environmental and biological factors and can change according to seasonality. In general, the activity pattern of species of the order Carnivora is influenced by air temperature and humidity, prey activity pattern, human presence, and competition. To answer whether there is temporal niche segregation between Cerrado carnivore species and whether the pattern of activity of Cerrado carnivores changes between the two well-marked seasons of the biome, we collected data on native carnivores with camera traps over a year. Species were active mainly in the twilight and night periods, with high overlap in their activity schedules. Activity patterns of the crab-eating fox and puma were significantly different, which indicates that the canid may be avoiding the competing species in time to avoid agonistic interactions. Furthermore, the peak activity periods of the four carnivore species do not overlap, suggesting that competition is a secondary mechanism determining the activity pattern of these species. The activity patterns of the species did not differ significantly between seasons. However, the crab-eating fox tended to be more diurnal in the rainy season, while the puma tended to be more diurnal in the dry season.

Influência da competição de interferência e da sazonalidade nos padrões de atividade de mamíferos carnívoros no cerrado brasileiro. O padrão de atividade das espécies pode ser influenciado por fatores ambientais e biológicos e mudar conforme a sazonalidade. Espécies da ordem Carnivora em geral têm o padrão de atividade influenciado pela temperatura e umidade do ar, pelo horário de atividade das presas, pela presença humana e pela competição. Para responder se há segregação de nicho temporal entre espécies de carnívoros do Cerrado e se o padrão de atividade dos carnívoros do Cerrado muda entre as duas bem-marcadas estações do bioma, coletamos dados de carnívoros nativos com armadilhas fotográficas ao longo de um ano. As espécies foram ativas principalmente nos períodos crepuscular e noturno, com alta sobreposição do horário de atividade. Os padrões de atividade do cachorro-do-mato e da suçuarana foram estatisticamente diferentes, o que indica que o canídeo pode estar evitando a espécie competidora no tempo para evitar interações agonísticas. Além disso, os horários de pico de atividade das quatro espécies de carnívoros não se sobrepõem, sugerindo que a competição é um mecanismo secundário na determinação do padrão de atividade dessas espécies. Os padrões de atividade das espécies não diferiram significativamente entre as estações, mas o cachorro-do-mato mostrou tendência a ser mais diurno na estação chuvosa, enquanto a suçuarana tendeu a ser mais diurna na estação seca.

Graphical abstract for the article “Influence of interference competition and seasonality on the activity patterns of carnivorous mammals in the Brazilian Cerrado” (Oliveira Machado et al., 2023)

Diversidad de carnívoros (Carnivora) en un paisaje periurbano en los Andes Centrales de Colombia

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La diversidad de carnívoros en los Andes tropicales es alta y única, pero la transformación de los hábitats naturales en esta eco-región afecta negativamente la riqueza y abundancia en diferentes ensamblajes de este grupo. En este trabajo describimos la diversidad de carnívoros presentes en una región periurbana de los Valles de Aburrá y San Nicolás, en los Andes Centrales de Colombia, y documentamos las diferencias en el ensamblaje de carnívoros entre bosques nativos y plantaciones forestales (las principales coberturas boscosas). Utilizamos 46 estaciones de fototrampeo (2785 días-cámara) y realizamos 86 recorridos de observación (173 h) para su registro. Detectamos 12 carnívoros silvestres y dos especies domésticas en todo el paisaje. Se registró anecdóticamente a la nutria neotropical Lontra longicaudis, y el grisón Galictis vittata no fue registrado. Las especies de carnívoros silvestres más frecuentes fueron el zorro de monte Cerdocyon thous, el tigrillo Leopardus tigrinus y el cusumbo andino Nasuella olivacea. Sin embargo, la especie dominante en el ensamblaje fue el perro doméstico Canis familiaris, para el cual solo se incluyeron los registros de perros de libre deambulación, lo que representa una amenaza para la diversidad local. Existieron diferencias estadísticas en la diversidad verdadera (qD) del ensamblaje de carnívoros entre los bosques nativos (mayor diversidad) y las plantaciones forestales (menor diversidad) establecidas en la zona. Son necesarios estudios específicos sobre el uso del paisaje para cada una de las especies y modelos de ocupación para entender cómo las variables ambientales y antrópicas pueden afectar su abundancia y distribución en esta región periurbana.

Diversity of carnivores (Carnivora) in a periurban landscape in Central Andes of Colombia. The diversity of carnivores in the tropical Andes is high and unique, but the transformation of natural habitats in this eco-region has negatively affected the richness and abundance of the different assemblages of this group. Here we describe the diversity of carnivores occurring in a peri-urban region around Aburrá and San Nicolás metropolitan valleys, in the Central Andes of Colombia, and document differences in the assemblage of carnivores between native forests and timber plantations. We used 46 camera traps (2785 camera days) and 86 observation walks (173 h) to detect the carnivores. We detected 12 wild and two domestic carnivores species across the peri-urban landscape. In addition, we anecdotally detected the neotropical otter Lontra longicaudis, and the grison Galictis vittata was not detected. The most frequent wild carnivore species were the crab-eating fox Cerdocyon thous, the oncilla Leopardus tigrinus and the andean coati Nasuella olivacea. However, the dominant species in the assemblage was the domestic dog Canis familiaris, for which only records of free-roaming or feral individuals were included. This should be considered as a potential threat to local diversity. There were statistical differences in the true diversity (qD) of the carnivore assemblage between native forest (more carnivore diversity) and timber plantations (less carnivore diversity) established in the area. Species-specific studies on the use of the landscape and occupation models are necessary to understand how environmental and anthropogenic variables affect their abundance and distribution in this peri-urban region.

Graphical abstract for the article “Diversidad de carnívoros (Carnivora) en un paisaje periurbano en los Andes Centrales de Colombia” (Sánchez-Londoño et al., 2023)

Integrative taxonomy of the mountain cavy Galea musteloides Meyen, 1833, a highland neotropical caviomorph rodent

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The mountain cavy Galea musteloides Meyen, 1833 is a terrestrial caviomorph rodent with diurnal and colonial habits. It occupies grassland areas and rocky shrub steppes in the arid highlands of the central Andes of western Bolivia, northern Chile, and southeastern Peru. Recent phylogenetic studies based on the analysis of mitochondrial DNA showed that this species has a genealogy geographically structured into two main clades, one encompassing those populations usually referred to G. m. auceps (Thomas, 1911) and G. m. musteloides, and another referable to G. m. boliviensis (Waterhouse, 1848). Multivariate statistical analysis of 16 craniodental measurements corresponding to seven geographical groups supports this conclusion, allowing us to recognize two subspecies within musteloides, for which the names of musteloides (including auceps) and boliviensis (including G. monasteriensis Solmsdorff, Kock, Hohoff, & Sachser, 2004) are available. Due to some uncertainties in the original reference, we also restricted the type locality of G. musteloides to Pisacoma, Puno, Peru.

Taxonomía integrativa en el cuis de montaña Galea musteloides Meyen, 1833, un roedor caviomorfo de las tierras altas neotropicales. El cuis de montaña Galea musteloides Meyen, 1833 es un roedor caviomorfo terrestre, de hábitos diurnos y coloniales. Ocupa pastizales y estepas arbustivas rocosas en las tierras áridas y altas de los Andes centrales del oeste de Bolivia, norte de Chile y sureste de Perú. Estudios filogenéticos recientes basados en el análisis de ADN mitocondrial mostraron que esta especie tiene una genealogía estructurada geográficamente en dos clados principales, uno que engloba aquellas poblaciones generalmente referidas a G. m. auceps (Thomas, 1911) y G. m. musteloides, y otro atribuible a G. m. boliviensis (Waterhouse, 1848). El análisis estadístico multivariado de 16 medidas craneodentarias, correspondientes a siete grupos geográficos, respalda esta conclusión, lo que nos permite reconocer dos subespecies dentro de G. musteloides, para las cuales los nombres musteloides (incluyendo auceps) y boliviensis (incluyendo G. monasteriensis Solmsdorff, Kock, Hohoff & Sachser, 2004) están disponibles. Debido a algunas dudas de la referencia original, también restringimos la localidad tipo de G. musteloides a Pisacoma, Puno, Perú.

Graphical abstract for the article “Integrative taxonomy of the mountain cavy Galea musteloides Meyen, 1833, a highland neotropical caviomorph rodent” (Krapovickas et al., 2023)

Distribution of short and long-beaked common dolphin morphs (Delphinus spp.) based on skull’s rostrum index analysis along the Peruvian and Chilean coast

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The distribution of the long-beaked and short-beaked common dolphin morphs in the eastern South Pacific is not well defined. The objective of this study was to propose a potential distribution of the two forms along the coast of Peru and part of Chile based on the rostral index obtained from the ratio of rostral length and zygomatic width. This phenotypic criterion was implemented in skulls deposited in museum collections in Peru and Chile. Based on classification, we were able to determine the distribution of each morphotype considering the collection location. A total of 44 skulls were analyzed, three of which did not have collection location. The results show that both forms of the common dolphins were distributed along the coast of Peru, but only the short-beaked common dolphin occurred in Chile. A larger number of short-beaked specimens were detected, especially in northern Peru. It was remarkable that the long-beaked was less common than expected since it is usually sighted in neritic waters. Around the 13° S latitude degrees there seems to be an overlapping area with specimens of the two forms. Our study provides an analysis of the distribution of the two forms of common dolphins by implementing a discrimination index developed for North Pacific populations. Some patterns of segregation were observed, but this should be contrasted with a larger number of skulls and the application of other phenotypic criteria specific to the South Pacific.

Distribución de delfín común (Delphinus spp.) de hocico corto y hocico largo en base al índice rostral a lo largo de la costa de Perú y Chile. La distribución de los morfotipos de delfín común de hocico largo y de hocico corto en el Pacífico suroriental no está claramente definida. El objetivo de este estudio fue proponer una distribución potencial de ambas formas de delfines comunes a lo largo de la costa de Perú y parte de Chile en base al índice rostral obtenido a partir de la relación del ancho cigomático y la longitud rostral. En esta investigación se implementa este criterio fenotípico en cráneos depositados en colecciones de museos del Perú y Chile. A partir de la clasificación, pudimos determinar la distribución de cada morfotipo considerando la localidad de colecta. El total de cráneos analizados fue de 44, tres de los cuales no contaron con localidad de colecta disponible. Los resultados indican que las dos formas de delfines comunes se distribuyeron a lo largo de la costa de Perú, pero en Chile solo estuvo presente el de hocico corto. Se detectó un mayor número de ejemplares de hocico corto, particularmente en las zonas del norte del Perú. Es notable que la variedad de hocico largo sea menos frecuente de lo esperado, ya que es usualmente reportado en aguas neríticas. Alrededor de los 13° de latitud sur sería un área donde se superponen ambas formas. Nuestro estudio proporciona un análisis de la distribución de las dos formas de delfines comunes mediante la implementación de un índice de discriminación desarrollado para poblaciones del Pacífico Norte y muestra algunos patrones de segregación que deben ser contrastados con una mayor cantidad de cráneos e implementado otros criterios fenotípicos más específicos para el Pacífico Sur.

Graphical abstract for the article “Distribution of short and long-beaked common dolphin morphs (Delphinus spp.) based on skull’s rostrum index analysis along the Peruvian and Chilean coast” (Santillán et al., 2023)