Wlodzimierz Jedrzejewski

Venezuelan Institute for Scientific Research | IVIC · Centro de Ecología

The ecology and evolution of reproductive timing and synchrony has been a topic of great interest in evolutionary ecology for decades. Originally motivated by questions related to behavioural and reproductive adaptation to environmental conditions, the topic has acquired new relevance in the face of climate change. However, there has been relativel...

ContextBehavioral adjustments by large carnivores can be a key factor facilitating their coexistence with people in shared landscapes. Landscape composition might be a key factor determining how large carnivores can adapt to occurring alongside humans, yet broad-scale analyses investigating adjustments of habitat use across large gradients of human...

Habitat selection is a multi-scale process driven by trade-offs between benefits, such as resource abundance, and disadvantages, such as the avoidance of risk. The latter includes human disturbances, to which large carnivores, with their large spatial requirements, are especially sensitive. We investigated the ecological processes underlying multi-...

All animals, including carnivores, adapt their daily activity duration and distribution to satisfy food demands, breed, or avoid mortality risk. We used the kernel density method to estimate daily movement activity levels and movement activity patterns of jaguars in Hato Piñero, in Venezuelan Western Llanos, based on 3,656 jaguar detection time rec...

Anthropogenic hybridization is widely perceived as a threat to the conservation of biodiversity. Nevertheless, to date, relevant policy and management interventions are unresolved and highly convoluted. While this is due to the inherent complexity of the issue, we hereby hypothesize that a lack of agreement concerning management goals and approache...

At the biogeographic scale, spatial variation in diets may reflect not only the ecological flexibility of carnivore feeding habits, but also evolutionary adaptations of different populations within a species. We described the large-scale pattern in brown bear Ursus arctos predation on ungulates, its selectivity for ungulate species, and its relativ...

Broad scale population estimates of declining species are desired for conservation efforts. However, for many secretive species including large carnivores, such estimates are often difficult. Based on published density estimates obtained through camera trapping , presence/absence data, and globally available predictive variables derived from satell...

Pearson correlation matrix for jaguar density estimates (dependent variable) and a set of predictive variables. (DOCX)

Spatial distribution of the posterior standard deviations of adjusted jaguar density estimates. (DOCX)

Estimates of jaguar populations within protected areas by current range countries. (DOCX)

Spatial distribution of the posterior standard deviations of estimated probabilities of jaguar occurrence. (DOCX)

Density estimates and other relevant data used for the analysis of spatial variation in jaguar population densities. (DOCX)

Candidate predictive variables used in the spatial analysis. (DOCX)

Pearson correlation matrix for the jaguar occurrence (dependent variable) and a set of predictive variables. (DOCX)

Estimates of jaguar population across historical range. (DOCX)

Discussion of possible effect of increased pixel size of covariate layers on the precision of population size estimates. (DOCX)

Simulation to validate hierarchical model; methods and associated R code. (DOC)

Spatial distribution of the posterior standard deviations of jaguar potential density estimates. (DOCX)

Excel database containing presence—absence data used for modelling probability of jaguar occurrence. (RAR)

Hybridisation between a domesticated species and its wild ancestor is an important conservation problem, especially if it results in the introgression of domestic gene variants into wild species. Nevertheless, the legal status of hybrids remains unregulated, partially because of the limited understanding of the hybridisation process and its consequ...

Retaliatory killing of large carnivores in response to their attacks on cattle is recognised as one of the most important factors causing worldwide declines of large carnivores. Conversely, hunting is believed to have been largely eliminated due to national and international protection measures. We studied the prevalence of human-jaguar conflict an...

EL CAMBIO EPISTÉMICO EN LA DISCIPLINA DE LA CONSERVACIÓN BIOLÓGICA Y EL DIÁLOGO DE SABERES Desde los años sesenta y setenta se ha enfatizado progresivamente la inter, la trans y la metadisciplinariedad, en las cuales distintas disciplinas están relacionadas unas con otras y se alcanzan niveles de comprensión que transcienden a las disciplinas indiv...

Density is crucial for understanding large carnivore ecology and conservation, but estimating it has proven methodologically difficult. We conducted 1 year of camera trapping to estimate jaguar (Panthera onca) density and population structure in the Los Llanos region of Venezuela on the Hato Piñero ranch, where hunting is prohibited and livestock a...

Resumen. El temor que los humanos le tienen a los jaguares es uno de los princi-pales impedimentos en los esfuerzos de conservación. El objetivo de este capítulo es demostrar a través de un resumen de experiencias de encuentros, así como reportes de la literatura, que los jaguares no suponen un peligro a la integridad física de los humanos. A parti...

Although most often considered independently, subsistence hunting, domestic trade, and international trade as components of illegal wildlife use (IWU) may occurs near one another (spatially correlated). Understanding how and where subsistence and commercial uses may co-occur has important implications for the design and implementation of effective...

Sirénido corpulento que mide alrededor de tres metros y pesa entre 500 y 600 kg. Tiene un aspecto pisciforme, como un torpedo grueso, con aletas anteriores a manera de remos y una cola redondeada en forma de espátula. Todos estos rasgos son adaptaciones evolutivas de la especie al medio acuático. El dorso, la cabeza y el vientre son de color pardo...

http://animalesamenazados.provita.org.ve/content/yaguar-0

Resumen. Durante el siglo 20 las poblaciones de yaguar Panthera onca en Venezuela disminuyeron dramáticamente. Se mataron a los yaguares, por el miedo, como una fuente adicional de dinero, por la depredación del ganado y por deporte. Originalmente, habitaban la mayor parte del territorio de Venezuela a excepción de las partes altas de los Andes, zo...

Moose, Alces alces (Linnaeus, 1758), survived the European Pleistocene glaciations in multiple southern refugia, in a northern refugium near the Carpathians and possibly in other locations. During the second millennium ad, moose were nearly extirpated in Europe and only recolonized their current range after World War II. The number and location of...

Killing behavior and consumption rate are important components which determine 16 final predation rate. We studied predatory behavior of a female jaguar with one offspring in 17 Hato Piñero in Venezuelan Los Llanos. Seven carcasses of freshly killed calves were found 18 over a period of 9 days. Automatic video recording was used to document jaguar...

Predatory behavior and kill rate of a female jaguar (Panthera onca) on cattle Abstract: Killing behavior and consumption rate are important components that determine the final preda-tion rate. We studied the predatory behavior of a female jaguar with one offspring in Hato Piñero in Venezuelan Los Llanos. Seven carcasses of freshly killed calves wer...

La conectividad ecológica y el "dialogo de saberes" para promover la conservación del Yaguar Panthera onca en Venezuela RESUMEN 19 Durante el siglo 20 las poblaciones de yaguar Panthera onca en Venezuela disminuyeron 20 dramáticamente. Se mataron a los yaguares, por el miedo, como una fuente adicional de dinero, 21 por la depredación del ganado y...

Genomic resources developed for domesticated species provide powerful tools for studying the evolutionary history of their wild relatives. Here we use 61K single-nucleotide polymorphisms (SNPs) evenly spaced throughout the canine nuclear genome to analyse evolutionary relationships among the three largest European populations of grey wolves in comp...

Phylogeographic studies of highly mobile large carnivores suggest that intra-specific genetic differentiation of modern species might be the consequence of the most recent Pleistocene glaciation. However, the relative influence of biogeographical processes and subsequent human-induced population fragmentation requires a better understanding. Poland...

Dispersal and gene flow in populations of highly mobile mammals, such as wolves, are often determined by the landscape structure and ecological connectivity. Previous studies on the genetic struc- ture of Polish wolves revealed three major subpopulations: Carpathian Mountains in southern Poland, Roztocze in the southeast, and the Lowland in northea...

Phylogeographic studies of highly mobile large carnivores suggest that intra-specific genetic differentiation of modern species might be the consequence of the most recent Pleistocene glaciation. However, the relative influ-ence of biogeographical processes and subsequent human-induced population fragmentation requires a better under-standing. Pola...

The aim of this study was to examine the effects of sex and age of individuals, season, and human pressure (both human presence and habitat structure) on spatiotemporal behavior of wild boar (Sus scrofa). Specifically, we compared wild boar behavior under contrasting conditions of human pressure, within the primeval temperate forest of Białowieża (...

The aim of this study was to examine the effects of sex and age of individuals, season, and human pressure (both human presence and habitat structure) on spatiotemporal behavior of wild boar (Sus scrofa). Specifically, we compared wild boar behavior under contrasting conditions of human pressure, within the primeval temperate forest of Białowieża (...

Wolves (Canis lupus) belong to 3 genetically distinct subpopulations despite the absence of topographic barriers limiting dispersal. Based on data on wolf diets from 13 localities and wolf kill remains from a national-scale census, we investigated regional variation in wolf diet in relation to species structure of ungulate communities and spatial g...

Cyclic population dynamics of small mammals are not restricted to the boreal and arctic zones of Eurasia and North America, but long-term data series from lower latitudes are still less common. We demonstrated here the presence of periodic oscillations in small mammal populations in eastern Poland using 22-year (1986-2007) trapping data from margin...

Recent studies on highly mobile carnivores revealed cryptic population genetic structures correlated to transitions in habitat types and prey species composition. This led to the hypothesis that natal-habitat-biased dispersal may be responsible for generating population genetic structure. However, direct evidence for the concordant ecological and g...

Sample information and δ15N and δ13C isotope profiles (‰) for wolf prey species analyzed in this study. (PDF)