Javier A. Pereira

• Dr
• Investigador Independiente at Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"

The objective of this work was to analyze the species richness and conservation status of terrestrial mammals in Argentina in relation to protected areas and human footprint intensity using a spatially explicit metric. We calculated the conservation value per species integrating taxonomic singularity, chorology and national conservation category. W...

Dataset containing information for Geoffroy's cat (Leopardus geoffroyi) samples from Argentina, Uruguay, Brazil and Bolivia, genotyped for 11 microsatellites markers. Markers FCA441 and F124 showed evidence of linkage, but the former had higher PID and therefore we discarded it from the analyses. Geographic origin of samples is provided as geograph...

Geoffroy's cat (Leopardus geoffroyi) is a small‐sized felid native to South America. Given the species' distribution covering a wide variety of habitats, and the presence of high levels of anthropization in part of its range, it is possible that genetically differentiated groups exist and that they occupy different climatic niches. We assessed patt...

Populations in isolated and small fragments lose genetic variability very fast and are usually of conservation concern because they are at greater risk of local extinction. The largest native deer in South America, Blastocerus dichotomus (Illiger, 1815), is a Vulnerable species according to the IUCN categorization, which inhabits tropical and subtr...

Mammalian carnivores exert direct and indirect effects on communities through top-down control and trophic ecology studies are helpful to understand the ecological processes behind these interactions. However, most diet studies reveal only local patterns. Large-scale biogeographic and anthropogenic drivers can also influence carnivore diet patterns...

El gato del pajonal uruguayo Leopardus munoai es un felino endémico de áreas abiertas de Uruguay, sur de Brasil y noreste de Argentina, con escasos registros recientes documentados. Se reporta el hallazgo de un ejemplar atropellado sobre la ruta 43, departamento de Tacuarembó, Uruguay, en un área de pastizales previamente definida como de idoneidad...

Pigmentation anomalies (e.g., albinism, leucism) in Neotropical mammals are considered rare. Identifying the spatiotemporal distribution and prevalence of pigmentation anomalies is important to better assess the evolutionary basis of color variation. The southernmost population of the marsh deer (Blastocerus dichotomus) occurs within a relatively s...

Activity is an important aspect of animal behavior. Intrinsic and extrinsic factors can shape species activity patterns, which can alter and reshape several ecological aspects of the species. Human disturbance is known to modify the activity patterns of various species. The Marsh deer (Blastocerus dichotomus) is the largest Neotropical cervid, and...

Extreme stochastic perturbations can affect population dynamics, but quantitative assessments are scarce for threatened species. The 2015-2016 El Niño-Southern Oscillation (ENSO) caused extreme flooding in the Delta of the Paraná River in Argentina where the southernmost population of the regionally endangered marsh deer (Blastocerus dichotomus) oc...

Animals moving through landscapes need to strike a balance between finding sufficient resources to grow and reproduce while minimizing encounters with predators. Because encounter rates are determined by the average distance over which directed motion persists, this trade-off should be apparent in individuals’ movement. Using GPS data from 1,396 in...

Resumen. El ciervo axis o chital es nativo del subcontinente indio. Es una especie generalista de hábitat que evita ambientes extremos. Su sistema digestivo es de un consumidor intermedio y se alimenta de gran variedad de plantas, principalmente pasturas. Puede formar grupos de más de 150 individuos y alcanzar altas densidades en áreas protegidas l...

Aim The use of landscape resistance maps to model connectivity has become an indispensable tool for species conservation. However, different methods can be used to estimate landscape resistance, but there is no consensus on which is the most reliable one. Therefore, comparing the performance of those methods in predicting resistance can be quite us...

RED LIST ASSESSMENT OF THE MAMMALS OF ARGENTINA 2019: SUMMARY AND ANALYSIS OF THREATS. Assessing the extinction risk of species has become an important decision tool for the implementation of species conservation policies. In this work we summarize the result of the latest oficial categorization of the mammals of Argentina with emphasis on the thre...

The Vulnerable marsh deer Blastocerus dichotomus, the largest native cervid in South America, is declining throughout its range as a result of the conversion of wetlands and overhunting. Estimated densities in open wetlands of several types are 0.1–6.8 individuals per km2. We undertook the first unmanned aerial vehicle (UAV) survey of the marsh dee...

Optimising conservation efforts requires an accurate record of the extant species as well as their geographic distributions. Nevertheless, most current conservation strategies start from an incomplete biodiversity inventory. Argentina has an extraordinary diversity of species, however, until now an updated inventory of its fauna has not been carrie...

Deer species can cause serious damages to trees through browsing and antler rubbing, and these impacts can generate significant economic losses. As a tool to minimize damages to trees by deer, repellents based on odor, visual and/or taste stimulus have been developed and tested. Repellents vary greatly in terms of costs, forms of use, duration, and...

Un inventario biológico enumera, ordena, cataloga y/o cuantifica ecorregiones, ecosistemas o especies. Es una herramienta básica y fundamental de gestión ambiental, que, al mismo tiempo, constituye la primera medida de conservación, dado que no se puede cuidar aquello que es ignorado. El presente Inventario Biológico Argentino es el esfuerzo de un...

Felids are among the species most threatened by habitat fragmentation resulting from land-use change. In the Uruguayan Savanna ecoregion, about 30% of natural habitats have been lost, large felids have been eradicated from most of the region, and the impact of anthropogenic threats over the smaller species that remain is unknown. To develop managem...

Identifying factors that create and maintain a hybrid zone is of great interest to ecology, evolution and, more recently, conservation biology. Here, we investigated the role of environmental features in shaping the spatial dynamics of a hybrid zone between the southern tigrina, Leopardus guttulus, and Geoffroy’s cat, L. geoffroyi, testing for exog...

Mammal herbivores, and specially deer, can cause severe damages to agriculture, producing economic losses. Repellents based on odor, visual and/or taste stimuli have been tested to minimize these damages, but their global effectiveness has not been quantified. A systematic literature review on the use of repellents to reduce damage by deer was carr...

Assessments of the role that small (<500 km²) protected areas play in conservation of large carnivores in landscapes where the species are persecuted are scarce. Using camera-trap sampling we estimated puma (Puma concolor) population abundance, site use intensity, and relative abundance of prey in Lihué Calel National Park (320 km²) and two neighbo...

Leopardus geoffroyi is a small feline with a widespread distribution in a broad array of habitats. Here we investigate its evolutionary history to characterize the phylogeographical patterns that led to its present distribution using mitochondrial DNA from 72 individuals collected throughout its entire range. All haplotypes conformed to a monophyle...

The marsh deer (Blastocerus dichotomus) is the largest deer native to South America, occurring in wetlands and marshy habitats. The southernmost population of the species is found in the Paraná River Delta,Argentina, in a wetland system highly modified by intensive forestry activity. Foresters perceive high levels of economic losses attributed to d...

En paisajes dominados por el hombre múltiples disturbios antrópicos degradan las interacciones depredador-presa. El sobrepastoreo por ganado puede afectar la base de presas silvestres, pero la introducción de herbívoros tanto domésticos como silvestres puede subsidiar energéticamente a las poblaciones de carnívoros. La caza en represalia por ataque...

Assessment of the conservation status for Argentina

El ciervo de los pantanos es una especie dependiente de ambientes de humedales y está sujeto a una alta presión de caza furtiva. Su rango de distribución se encuentra fragmentado en al menos cuatro subpoblaciones. Si bien la subpoblación de los Esteros del Iberá y áreas adyacentes, en la provincia de Corrientes, ha experimentado una importante recu...

Transboundary conservation of northern pampas carnivores of northeastern Argentina, southern Brazil and Uruguay.

Because of the great diversity (28 species) and fragile conservation status (57.1% of species are in threat of extinction) of the terrestrial carnivores of Argentina, we aimed to collect information about the conservation efforts in this country and identify tools to improve their effectiveness through expert opinion. Lack of interest by government...

Because of the great diversity (28 species) and fragile conservation status (57.1% of species are in threat of extinction) of the terrestrial carnivores of Argentina, we aimed to collect information about the conservation efforts in this country and identify tools to improve their effectiveness through expert opinion. Lack of interest by government...

RESUMEN Debido a la gran diversidad (28 especies) y el delicado estado de conservación (57,1% de especies con amenaza de extinción) de los carnívoros terrestres en Argentina, nos propusimos recopilar información sobre los esfuerzos actuales de conservación en este país y, mediante consulta a expertos, identificar medidas para mejorar su eficacia. E...

A nivel mundial, los ciervos (Familia Cervidae) ocasionan más daño sobre cultivos agrícolas, forestaciones y plantaciones ornamentales que cualquier otra especie de la fauna silvestre. Diferentes métodos, mayormente basados en estímulos odoríferos y/o de sabor, han sido propuestos para repelerlos, obteniéndose distintos niveles de éxito. El ciervo...

Geoffroy’s cat (Leopardus geoffroyi) is a small Neotropical felid whose social behavior remains poorly understood. We used simultaneous radiotelemetry (4 males and 3 females) and camera trapping to examine the spatial structure and dynamics of a population of this species in the Brazilian pampas (part of the Uruguayan Savannah ecoregion), including...

The marsh deer (Blastocerus dichotomus) is the largest native cervid of South America and is categorized as Vulnerable on the IUCN Red List. The southernmost population of this deer is found in the lower Delta of the Paraná River in Argentina. Due to poaching, habitat loss, and predation by dogs, it has been proposed to upgrade the conservation sta...

Mitigating carnivore-livestock interaction is essential to ensuring the persistence of carnivores in landscapes dominated by livestock activity. Our aim was to explore, in the context of social and productive crises triggered by environmental events, the values and attitudes adopted by smallholders in relation to wild carnivores. We performed semi-...

Tema/Meio de apresentação: Evolução/Oral Polymorphic phenotypes have often been inferred to play some adaptive roles in ecological, physiological and behavioral processes. Melanism is a coloration polymorphism that is present in various groups of organisms and it is rather common in the Felidae family. The Geoffroy's Cat (Leopardus geoffroyi) is a...

Wild ungulates, and particularly deer, can cause severe damage to commercial plantations, resulting in reduced tolerance of their presence by forestry producers. The marsh deer Blastocerus dichotomus , categorized as Vulnerable on the IUCN Red List, is declining throughout South America. A population of c. 500 individuals survive within a matrix of...

Las consecuencias de las prácticas forestales sobre la biodiversidad varían según el manejo silvícola, del agua y el hábitat sustituido. Las plantaciones forestales pueden ser diseñadas y manejadas para preservar las especies silvestres y mantener las funciones ecosistémicas. Sin embargo, se requiere de un trabajo interdisciplinario y del consenso...

The consequences of forestry practices on biodiversity vary according to silvicultural treatments, water system management and the natural habitat that is replaced. Commercial planta-tions can be designed and managed to preserve wild species and to maintain ecosystem functions. However, interdisciplinary work and consensus among key stakeholders ar...

El presente proyecto tuvo dos objetivos: (1) Evaluar el impacto de la inundación extraordinaria y la cacería furtiva sobre la ocupación y abundancia relativa del ciervo de los pantanos en el Núcleo Forestal del Bajo Delta del Paraná, y (2) Cuantificar el impacto directo de la inundación extraordinaria y la cacería furtiva (en términos de canti...

En los meses de julio de 2015 y enero de 2016 se colectaron garrapatas de un gato montés (Leopardus geoffroyi) localizado en la provincia de Buenos Aires y de un canino doméstico (Canis lupus familiaris) en la provincia de Santa Fe, respectivamente. El objetivo del presente trabajo es reportar el primer registro de Amblyomma aureolatum en la provin...

Global conservation status assessment

A total of 111 samples (43 faeces and 79 gastrointestinal tracts) of 14 wild carnivore species from 12 Argentine provinces were analyzed. Helminth eggs were identified in 73% of the faecal samples and adult worms were recovered from 81% of the gastrointestinal tracts. We found 19 helminth species. Among the most frequent findings were parasites of...

The delta of the Paraná River in Argentina represents the southernmost stronghold for capybaras (Hydrochoerus hydrochaeris), but this area is highly modified due to commercial afforestations with Salicaceae. Water management (e.g. drainage of marshes) and land protections (e.g. polders) are carried out to improve field conditions for developing aff...

Understanding the fine-scale geographic distribution of a species has applications in biogeography, ecology, evolution and conservation. Species distribution models (SDM) have been widely used to predict geographic and climatic ranges of species. Geoffroy's cat Leopardus geoffroyi is a small felid of least concern that occupies a wide variety of ha...

Understanding the causes that structure natural communities has long been an important goal for biologists. The question of what regulates the distribution and abundance of species in communities is central because it connects widespread processes (e.g., competition, predation), historical effects, and the interactions of these competing mechanisms...

The understanding of the spatial structure and dynamics of populations can guide conservation decisions, but studies of this type focused on small (< 7 kg) carnivores are rare. We compared survival, reproduction, and dispersal of radiocollared Geoffroy's cats (Leopardus geoffroyi) in a protected area and adjacent cattle ranches in Argentina to asse...

Intraguild predation (IGP) and interspecific killing (IK) have been recently acknowledged as important ecological forces that could influence community structure. Not only can carnivores influence prey community composition, they might also impact the populations of other carnivores. The goal of the current study was to assess the role of IGP and I...

Wild carnivores share a high percentage of parasites and viruses with closely related domestic carnivores. Because of increased overlap and potential contact with domestic species, we conducted a retrospective serosurvey for 11 common carnivore pathogens in 40 Geoffroy's cats (Leopardus geoffroyi) sampled between 2000 and 2008 within or near two pr...

We compared diet composition, prey selection, home-range size, daily movements, and habitat preference of Geoffroy’s cats (Leopardus geoffroyi) between cattle ranches and an adjacent national park in scrublands of Argentina. Although overall prey abundance was higher in the park than in the ranches, diet composition was similar between sites, and s...

Small mammals usually constitute the main prey for Leopardus geoffroyi throughout its distribution. We studied the patterns of small rodent selection by this felid in a semi-arid scrubland of central Argentina, addressing whether prey choice may be related to the availability, morphology, and distribution of the different rodent species. Cat’s diet...

We present quantitative data on the impact of different causes of mortality in a Geoffroy’s cat (Leopardus geoffroyi) population inhabiting a protected area and adjacent cattle ranches in central Argentina. Between December 2000 and January 2009, we used three methods to collect data on causes of mortality in both the park and the ranches: (1) info...

RESUMEN: Se reportan los primeros registros de presencia para cuatro especies de mamíferos (Dasypus novemcinctus, Cerdocyon thous, Procyon cancrivorus y Axis axis) en el sector bonaerense del Bajo Delta del Río Paraná y bajíos ribereños adyacentes, Argen-tina. La inexistencia de datos previos para estas especies en la zona, pese a que se trata de u...

We report the first records of presence of four mammal species (Dasypus novemcinctus, Cerdocyon thous, Procyon cancrivorus, and Axis axis) for the Lower Delta of the Paraná river and adjacent coastal lowlands, Buenos Aires province, Argentina. The absence of previous records of these species in the area, although it is a previously well surveyed ar...

The activity pattern of mammalian carnivores is influenced by several factors, including environmental conditions, interference from competitors, and behavioral thermoregulation. Facing extreme environmental conditions the activity rhythm of animals may change. The activity patterns of Geoffroy’s cats (Leopardus geoffroyi) were studied during a per...

We studied the density of a Geoffroy's cat Leopardus geoffroyi population in a semiarid scrubland of Argentina, by comparing density estimates obtained during camera-trapping surveys in a national park and in nearby cattle ranches in 2006 and 2007–2008. Overall, we obtained 247 pictures of Geoffroy's cats. The density (mean ±se) of the species at t...

DIET OF THE BURROWING OWL (ATHENE CUNICULARIA) IN TWO AREAS WITH DIFFERENT LAND USE IN SOUTH–CENTRAL LA PAMPA PROVINCE, ARGENTINA.— We studied the diet of the Burrowing Owl (Athene cunicularia) in two areas with different land use in the central sector of the Monte de Llanuras y Mesetas Ecoregion, La Pampa Province, Argentina: a protected area (Lih...

Se estudió la comunidad de pequeños mamíferos terrestres (<500 g) del Parque Nacional Lihué Calel (37°57¿S, 65°33¿O, provincia de La Pampa, Argentina) en 1993 y entre los años 2003 y 2006. Se documentaron datos sobre hábitat, ecología, reproducción y estructura de la población en los marsupiales Lestodelphys halli y Thylamys pallidior, los cricétid...

The plains vizcacha (Lagostomus maximus) and the greater rhea (Rhea americana) are considered to compete for forage with cattle in agroecosystems of South America. The aims of this research were to analyze the diet diversity and the trophic niche breadth of these three herbivores where they share a wetland area in Argentina, and to assess the exten...

Crab-eating foxes (Cerdocyon thous) and pampas foxes (Lycalopex gymnocercus) are very similar in body size and food habits, with distributional ranges that overlap extensively in South America. We used camera-trap records of both species obtained at the IberaNature Reserve (INR), northeastern Argentina, to test the hypothesis that, when living in s...

We studied the small mammal assemblage (bats, marsupials and rodents) of Parque Nacional Chaco and Capitán Solari(Chaco Province, Argentina) based on captures and analysis of owl pellets. Twenty-one species were recorded during abrief survey, including two marsupials, seven bats, and twelve rodents. In addition, we documented the first occurrenceof...

We studied the terrestrial small mammal (<500 g) assemblage from Parque Nacional Lihué Calel (37°57'S, 65°33'O, La Pampa Province, Argentina) in 1993 and 2003-2006. Information about habitat, ecology, reproduction, and population structure is provided for the didelphid marsupials Lestodelphys halli and Thylamys pallidior, the cricetid rodents Akodo...

Geoffroy's cat (Leopardus geoffroyi) is a little-known South American felid. Here we report the first detailed data on its seasonal food habits in a protected area of the central Monte desert, Argentina. We collected and analyzed 182 scats, identifying a total of 441 prey items, with 2.4±1.5 prey items per scat (range=1–10). Our results confirm tha...

We examined the numerical and spatial responses of Geoffroy's cats (Oncifelis geoffroyi) to a prey decline in central Argentina between April 2002 and November 2003. The 2nd year of the study coincided with a severe drought. Relative abundance of brown hares (Lepus europaeus) declined from 5.6 individuals/10 km during the predrought period to about...

Gastrointestinal parasites were collected from 7 free-ranging Geoffroy's cats, Oncifelis geoffroyi from Lihue Calel National Park, Argentina. Also, fecal samples were analyzed from these animals and 3 other sympatric ones. The helminths were identified as Vigosospirura potekhina, Didelphonema longispiculata, Pterygodermatites cahirensis, Trichuris...

RESUMEN: El Parque Nacional Pre-Delta (Entre Ríos, Argentina) es una unidad de conserv ación reciente en la región del Delta del Río Paraná y no dispone aún de información detallada sobre su biodiversidad. Con el objetivo de reconocer qué especies de felinos silvestres están presentes en la región se realizaron relevamientos a campo basados en avis...

Food habits of plains vizcacha (Lagostomus maximus), greater rhea (Rhea americana) and cattle (Bos taurus) in the Parana River Delta, Argentina, were studied over 2 years using micro-histological analysis of faeces. This was the first study of feeding habits of these herbivores grazing in common in a wetland of Argentina. Poaceae was the main diet...

Desarrollamos y comparamos dos programas de seguimiento de poblaciones silvestres de zorros a partir de dos metodologías alternativas para estimación de abundancia relativa, un índice basado en las visitas a las estaciones de cebado y otro en el recuento de signos en cuadrículas. Los programas de seguimiento se desarrollaron para detectar una dismi...

La Reserva Natural Otamendi integra el sistema de Parques Nacionales de la Argentina. Aquí presentamos un relevamiento de los animales vertebrados y analizamos su estado de conservación. Constituye una de las áreas naturales protegidas con mayor diversidad faunística de la provincia de Buenos Aires.

Pereira, J., Varela, D., & Fracassi, N. (2002). Pampas cat in Argentina: Is it absent from the Pampas. Cat News, 36:20-22.