Pablo Palencia

• PhD
• PostDoc Position at University of Oviedo

Wild boar (Sus scrofa) has become overabundant leading to significant ecological impact and human-wildlife conflicts. Thus, monitoring their populations has become essential. Human activities also influence ecological processes and disease dynamics. Therefore, understanding species interactions and community composition is crucial in habitats suffe...

Camera‐traps are valuable tools for estimating wildlife population density, and recently developed models enable density estimation without the need for individual recognition. Still, processing and analysis of camera‐trap data are extremely time‐consuming. While algorithms for automated species classification are becoming more common, they have on...

The European Observatory of Wildlife EOW, as part of the ENETWILD project, represents a collaborative network that has been operating since 2021 to develop and implement standardized protocols to obtain harmonized data on distribution and density of target mammal species. In so doing, the EOW aims at contributing to improving the quality of data th...

Tick-borne zoonoses are an emerging health issue. The expansion of ticks is mainly driven by climatic changes but also by new approaches to the management of the natural environment, increasing the abundance of vertebrate host species and thus the potential exposure to tick bites for both humans and companion animals. In this context, a holistic ap...

The increase in acarological risk of tick bites is significantly driven by profound changes in landscape, which alter the density and distribution of wildlife that support tick populations. As a result of habitat shifts and land abandonment, which create environments conducive to tick proliferation, the risk of disease transmission to humans and an...

The western capercaillie (Tetrao urogallus) is a species of conservation concern that has been experiencing a severe decline in many regions of Europe. The poor breeding success rather than mortality of full-grown birds has been suggested to be responsible for its decline, been the nest loss a potential driver of the low productivity (number of chi...

The random encounter model (REM) is a camera trapping method to estimate population density (i.e. number of individuals per unit area) without the need for individual recognition. The REM can be applied considering camera trap data only by tracking the passages of animals in front of the camera (i.e. sequences). However, it has not been assessed ho...

Camera-traps are valuable tools for estimating wildlife population density, and recently developed models enable density estimation without the need for individual recognition. Still, processing and analysis of camera-trap data are extremely time-consuming. While algorithms for automated species classification are becoming more common, they have on...

Presence of the Egyptian mongoose Herpestes ichneumon (Linnaeus, 1758) at the edge of the Cantabrian Mountains

Camera traps have transformed the way we monitor wildlife and are now routinely used to address questions from a wide range of ecological and conservation aspects. Sampling design optimization and a better understanding of drivers determining the precision of detection rates (i.e. the number of detections per unit of effort) are important methodolo...

ECOSISTEMAS consolidates its commitment to an open and fair publishing system and moves towards its internationalization

Acknowledgement to reviewers and guest editors of ECOSISTEMAS in the year 2023

Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amo...

The crested porcupine ( Hystrix cristata ) is a rodent present in Africa and southern Europe (Italy exclusively). The Italian population is expanding from the centre to the north and south, but little is known about the species' abundance. Reliable population density estimates are important for monitoring trends in wildlife populations and for deve...

Since 2007, an ongoing African swine fever (ASF) pandemic has significantly impacted Eurasia. Extensive field evidence and modeling confirm the central role of wild boar in ASF epidemiology. To effectively control and eradicate the infection, rapid detection of the ASF virus (ASFV) is crucial for prompt intervention in areas of recent viral introdu...

Camera traps are used to address questions from a wide range of ecological and conservation aspects. In this respect, sampling design optimization and a better understanding of drivers that determine detection rates are important methodological issues. Despite a wide range of factors that have already been explored, little attention has been played...

1. Density estimates guide wildlife management, and camera traps are commonly used to estimate sizes of unmarked populations. Unfortunately, animals often alter their natural behaviour in the presence of camera traps, which may bias subsequent density estimates. 2. We simulated 100 populations of known density to test several new and existing met...

Estimation of changes in abundances and densities is essential for the research, management, and conservation of animal populations. Recently, technological advances have facilitated the surveillance of animal populations through the adoption of passive sensors, such as camera traps (CT). Several methods, including the random encounter model (REM),...

Motion‐sensitive cameras are popular as non‐invasive monitoring tools, and several methods have been developed to estimate population densities from camera data. These methods frequently rely on auxiliary movement data including the distance traveled by an individual in a day and the proportion of the day that an animal spends moving when individua...

Habitat use is a virtually universal activity among animals and is highly relevant as regards designing wildlife management and conservation actions. This has led to the development of a great variety of methods to study it, of which resource selection functions combined with biologging-derived data (RSF) is the most widely used for this purpose. H...

Over the past few decades, the use of camera-traps has revolutionized our ability to monitor populations of wild terrestrial mammals. While methods to estimate abundance from individually-identifiable animals are well-established, they are mostly restricted to species with clear natural markings or else necessitate invasive and often costly animal...

The European Observatory of Wildlife (EOW, https://wildlifeobservatory.org/) is an EFSA-funded (European Food and Safety Authority) initiative run by the ENETWILD project (www.enetwild.com). The EOW aims to improve harmonizing wildlife monitoring methods throughout the Europe and provide the possibilities to estimate the density of wildlife across...

The native Eurasian wild boar (Sus scrofa) is a relevant wildlife host for African swine fever (ASF) virus, contributing to infection maintenance and spread and representing a challenge for disease control. Combining published scientific evidence with expert opinion, we provide an updated global overview of ASF control in wild boar and feral pigs i...

Estimation of changes in abundances and densities is essential for the research, management, and conservation of animal populations. Recently, technological advances have facilitated the surveillance of animal populations through the adoption of passive sensors, such as camera traps (CT). Several methods, including the random encounter model (REM),...

Abundance and density of animal populations are key parameters in wildlife studies. In wildlife management, estimating these parameters for species of interest is essential for quantifying variations and guiding conservation decision-making. The use of camera traps has proven to be an efficient and non-invasive methodology for monitoring wildlife p...

The European Observatory of Wildlife (EOW) as part of the ENETWILD project, aims to improve the European capacity for monitoring wildlife populations, implementing international standards for data collection, providing guidance on wildlife density estimation, and finally, to promote collaborative, open data networks to develop wildlife monitorin...

African swine fever (ASF) is a highly contagious disease affecting all suids and wild boar (Sus scrofa). Since 2007, ASF has spread to more than 30 countries in Europe and Asian regions, and the most recent outbreak has been in mainland Italy (reported on January 2022). When the genotype II of the ASF virus infects a population, a mortality rate cl...

In the One Health context, Integrated Wildlife Monitoring (IWM) merges wildlife health monitoring (WHM) and host community monitoring to early detect emerging infections, record changes in disease dynamics, and assess the impact of interventions in complex multi-host and multi-pathogen networks. This study reports the deployment and results obtaine...

The International Symposium on Wild Boar and Other Suids (IWBS 2022), which took place in Montseny Biosphere Reserve (Catalonia, Spain) in September 2022, provided to ENETWILD with the opportunity to meet in‐person for the first time after 2.5 years, and meet the international scientific community with expertise on wild suids and other ungulates. T...

During summer 2022, the European Wildlife Observatory (EOW²), involving 50 study areas in at least 30 European countries, has applied similar camera‐trapping‐based population estimation protocols and data collection standards to facilitate harmonization and interoperability. For this purpose, continuous training of the network of wildlife professio...

It is essential to provide tools to wildlife professionals and researchers in order to facilitate data collection on wildlife density estimation following standardized protocols in the field. This is relevant for efficient harmonized data management systems, from the field to final reporting. Our main objective was to facilitate the collection of i...

El mapache Procyon lotor (Linnaeus, 1758) es un mesocarnívoro originario del centro y norte de América que ha conseguido expandir su área de distribución enormemente gracias a introducciones y escapes de granjas y zoológicos. En España, tras las primeras observaciones realizadas a principios de siglo XXI como consecuencia de escapes de núcleos zool...

La estima de densidades poblacionales es un parámetro fundamental para la toma de decisiones en el ámbito de la conservación y la gestión la fauna silvestre. En este sentido, el uso de fototrampeo como herramienta para monitorizar los tamaños poblacionales ha ido adquiriendo importancia en los últimos 20 años, dándose un gran desarrollo tecnológico...

The main aims of this report are (i) to implement camera trap practical methods to estimate wild boar density by means of field trials, which is also of application to other medium and big sized mammals and (ii) to report on progress of the development of automatic identification for density estimation based on camera trapping. As for (i), we speci...

Human–wildlife conflicts are a growing problem in Northern Hemisphere where wild ungulates are one of the taxonomic groups most frequently involved. To mitigate these conflicts, it is essential to develop preventive actions able to avoid encounters between wildlife and human (activities). We here employed photo-trapping to evaluate the behaviour of...

Population density estimates are important for wildlife conservation and management. Several camera trapping‐based methods for estimating densities have been developed, one of which, the random encounter model (REM), has been widely applied due to its practical advantages such as no need for species‐specific study design. Nevertheless, most of the...

One of the main objectives of ENETWILD consortium is to collect data on density, hunting statistics and wildlife occurrence in order to model the geographical distribution and abundance of wildlife species across Europe as a tool to support the assessment of risks associated, for example, with disease transmission. Created in the framework of the E...

Abstract This report presents the results of field activities in relation to the generation of reliable wild boar density values by camera trapping (CT) in 19 areas in Europe, mainly in East Europe. Random Encounter Model (REM) densities ranged from 0.35±0.24 to 15.25±2.41 (SE) individuals/km2. No statistical differences in density among bioregion...

The 2nd ENETWILD Annual General Meeting took place on 5‐6th October 2021, bringing together experts, stakeholders and ENETWILD collaborators in online workshop discussions. First, workshop discussions contributed to the analysis and proposal of approaches for a harmonized European‐wide wildlife monitoring framework able of sustaining coordinated de...

A better understanding of population density (i.e. the number of individuals per unit area) is essential for wildlife conservation and management. Despite the fact that a wide variety of methods with which to estimate population density have already been described and broadly used, there are still relevant gaps. In the last few decades, the use of...

Contexto Probabilidad de detección Objetivo: identificar los factores que afectan a la probabilidad de detección y velocidad de disparo de las cámaras Fig. Diseño experimental Métodos 5 modelos Resultados & discusión CONCLUSIONES La probabilidad de detectar un individuo de una especie dada depende del modelo de cámara usado (no todas las cámaras de...

Camera trapping is a widely used tool in wildlife research and conservation, and a plethora of makes and models of camera traps have emerged. However, insufficient attention has been paid to testing their performance, particularly under field conditions. In this study, we have comparatively tested five of the most frequently used makes of camera tr...

Methods for estimating population densities of unmarked species using camera traps are still under development. One such method is called "Random Encounter Model (REM)" and, to our knowledge, has never been used to estimate densities of mountaindwelling ungulates. In this study, we tested the REM method to estimate the density of Balkan chamois ( R...

Wildlife populations are experiencing drastic changes in their areas of distribution and abundance in the last decades and, therefore, population monitoring programs should be implemented to support effective management strategies. In this case, we have focused on the Iberian wild goat (Capra pyrenaica) population nucleus from Parque Natural Valle...

Bluetongue is a vector-borne disease affecting domestic and wild ruminants, with a major socioeconomic impact. Endemic circulation of the bluetongue virus serotype 4 (BTV-4) and BTV-1 have occurred in Spain since 2004 and 2007, respectively. However, epidemiological studies have seldom been approached from a long-term perspective in wild ruminants....

Population density estimations are essential for wildlife management and conservation. Camera traps have become a promising cost‐effective tool, for which several methods have been described to estimate population density when individuals are unrecognizable (i.e. unmarked populations). However, comparative tests of their applicability and performan...

Camera‐trapping methods have been used to monitor movement and behavioural ecology parameters of wildlife. However, when considering movement behaviours to estimate DR is mandatory to include in the formulation the speed ratio, otherwise DR results will be biased. For instance, some wildlife populations present movement patterns characteristic of e...

Toxoplasma gondii is an obligate intracellular protozoan which infects warm-blooded vertebrates, including humans, worldwide. In the present study, the epidemiology of T. gondii was studied in the wild ungulate host community (wild boar, red deer, and fallow deer) of Doñana National Park (DNP, south-western Spain) for 13 years (2005–2018). We asses...

Camera trapping use has increased significantly in ecological studies in recent decades due to its ability to register information about cryptic and/or elusive species and, more recently, due to its ability to derive population parameters, such as population abundance or density. For these latter applications, camera traps set in a regular grid pat...

The general aim of this guidance is to review the methods for estimating relative abundance and density in wild ruminant species and give insights on how to obtain reliable estimations by using those methods. The results are a possible guideline on best practices to improve the accuracy and comparability of density methods. For these purposes, we r...

Animal tuberculosis (TB) is endemic in wild boar (Sus scrofa), red deer (Cervus elaphus), fallow deer (Dama dama) and cattle in south and central Spain. In order to clarify the processes that operate in the medium and long-term, we studied TB at the wildlife–livestock interface in Doñana National Park for 14 years (2006–2018) in relation to host de...

Hunting statistics can be suitable to determine wild boar density estimates if a calibration with an accepted rigorous method is performed. Here, densities calculated from drive counts during collective drive hunting activities are compared against density values calculated by camera trapping using the random encounter method. For this purpose, we...

Day range (DR), the distance travelled by an individual during the day, is an important metric in movement ecology that recently gained interest by its relevance for estimating population density through the random encounter model (REM). Traditionally, DR has been estimated using GPS technology and considering raw straight-line distances between co...

Distance sampling (DS) is a widely used method to estimate the population density of wild species. However, the precision of the estimates must be reduced to be effective in a monitoring program. This precision depends on the variability in group size, encounter rate and detection function. In gregarious species it is recommended to carry out sampl...

Knowledge about distribution and abundance of European wild mammals is essential for their conservation and management. ENETWILD consortium (www.enetwild.com) has been collecting presence and abundance data of wild boar, which will be completed with other wild mammals in the next years. Using the wild boar as a example, we develop a general framewo...

R code to resize photos obtained by camera-traps. The code allows resizing photos stored in different folders (e.g. a folder for each photo-trapping point). Useful to optimize the storage of information.

El muestreo de distancias (Distance Sampling, DS) es un método ampliamente usado para estimar la densidad de una población y actualmente es considerado uno de los métodos de referencia para el seguimiento poblacional de ungulados silvestres. El DS está basado en el concepto teórico de que la probabilidad de detectar un individuo disminuye según aum...

The Random Encounter Model (REM) allows for estimating wildlife population density based on camera-traps data without individual recognition. Day range (DR; i.e. daily distance traveled by an individual) is the most costly and time-consuming parameter for applying REM. Despite DR were traditionally estimated from telemetry data, several authors sho...

The Random Encounter Model (REM) is a method based on camera-traps data for estimating wildlife population densities without individual recognition. Although there are a plethora of methodologies to estimate wildlife population densities, for some relevant and elusive species, e.g. wild boar, there is not a feasible and reliable method able to deri...

El rango diario de desplazamiento (RD), entendido como la distancia recorrida por un individuo a lo largo del día, es un parámetro ecológico que ha sido tradicionalmente calculado mediante telemetría, asumiendo para ello trayectorias lineales entre localizaciones consecutivas. Sin embargo, la trayectoria que siguen los individuos entre dos localiza...

Day range (DR) is an ecological parameter that indicates the distance travelled by one animal over the day. DR is needed to estimate density of wildlife populations through random encounter model (REM), one of the most promising methods for monitoring wildlife since: i) produces population density values, and ii) based in camera trapping, allows us...

Day range and travel speed are important ecological variables that are usually measured by telemetry assuming straight-line distances between intermittent relocations of tagged animals. However, recent studies showed that telemetry can notably underestimate these parameters, mainly due to high tortuosity in animal paths. Here, we estimated travel s...