Bogdan Cristescu

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Verified

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• Ph.D.
• Lecturer in Mammal Ecology at University of Brighton

Kill rates and functional responses are fundamental to the study of predator ecology and the understanding of predatory-prey dynamics. As the most widely distributed apex predator in the western hemisphere, pumas ( Puma concolor ) have been well studied, yet a synthesis of their kill rates is currently lacking. We reviewed the literature and compil...

Ecologists are increasingly actively involved in conservation. We identify five key topics from a broad sweep of ecology that merit research attention to meet conservation needs. We examine questions from landscape ecology, behavioral ecology, ecosystem dynamics, community ecology, and nutrient cycling related to key topics. Based on literature rev...

Mortality site investigations of telemetered wildlife are important for cause‐specific survival analyses and understanding underlying causes of observed population dynamics. Yet, eroding ecoliteracy and a lack of quality control in data collection can lead researchers to make incorrect conclusions, which may negatively impact management decisions f...

Accurate aging is a useful tool in wildlife management, providing critical information for population dynamics research, age‐specific limiting factors, and conservation efforts. Many methods used to age mammalian carnivores are either invasive, expensive, or inconvenient to use in the field. In felids, the gum‐line recession has been found to accur...

Circadian rhythms are a mechanism by which species adapt to environmental variability and fundamental to understanding species behavior. However, we lack data and a standardized framework to accurately assess and compare temporal activity for species during rapid ecological change. Through a global network representing 38 countries, we leveraged 8....

Education and community outreach are fundamental to raising conservation awareness in rural communities for alleviating human–wildlife conflict (HWC). Evaluating the impacts of programs aimed at reducing HWC is necessary to justify the effectiveness of mitigation strategies, and to provide feedback for designing sustainable conservation initiatives...

Monitoring large carnivores is imperative for conservation planning, but is difficult due to their elusive behaviour and natural rarity. Some carnivores such as the cheetah (Acinonyx jubatus) are particularly wide ranging and often go undetected despite being present, or are detected at rates too low to make meaningful quantitative inferences. The...

Theory suggests that animals make hierarchical, multiscale resource selection decisions to address the hierarchy of factors limiting their fitness. Ecologists have developed tools to link population‐level resource selection across scales; yet, theoretical expectations about the relationship between coarse‐ and fine‐scale selection decisions at the...

Linear transportation infrastructure threatens terrestrial mammals by altering their habitats, creating barriers to movement and increasing mortality risk. Large carnivores are especially susceptible to the negative effects of roads due to their wide-ranging movements. Major road developments are planned or ongoing throughout the range of the Roman...

Transfrontier conservation landscapes, such as the Kavango–Zambezi Transfrontier Conservation Area (KAZA TCA) in southern Africa, play a crucial role in preserving global biodiversity and promoting the sustainable development of local communities. However, resources to facilitate management could become scarce across large areas, leading to difficu...

Mesocarnivores fill important roles in ecological communities globally, but their distribution and abundance are often understudied. Many species have historically been regarded as vermin and subject to lethal control due to their role in livestock predation. Identifying the factors influencing mesocarnivore populations can help disentangle their r...

Understanding species distributions is key for effective biodiversity conservation. We conducted a large-scale camera trapping survey in five systematic grids across central-eastern Namibia to identify drivers of large carnivore occupancy and to predict occurrence across a broader mixed-use landscape spanning 161,629 km2. Through targeted searches...

Conservation efforts are challenged by lack of funding and ambiguity in strategic prioritisation. Flagship species generate public attention but may not adequately represent and protect biodiversity. Integrating species‐centric approaches with area‐based strategies may refine conservation outcomes and could improve achievements towards biodiversity...

Reintroduction programmes are an important tool for the conservation of threatened and endangered carnivores, but their effectiveness has rarely been assessed when wild‐born, captive‐raised orphans are released. We monitored and evaluated the success of captive‐raised orphaned cheetahs (n = 25) that were rehabilitated and released into the wild as...

Rewilding landscapes through species or population restoration is an increasingly applied practice in biological conservation. There is expanding interest in wildlife release projects for apex predator population augmentation or reintroductions in historical ranges. Cheetahs (Acinonyx jubatus) are an IUCN Vulnerable-listed species with a declining...

Prey selection is a fundamental aspect of ecology that drives evolution and community structure, yet the impact of intraspecific variation on the selection for prey size remains largely unaccounted for in ecological theory. Here, we explored puma ( Puma concolor ) prey selection across six study sites in North and South America. Our results highlig...

Using a dataset of 591 capture events between 2001–2019 in California, USA, we examined the impact of capture methods and immobilization drugs on mountain lion ( Puma concolor ) welfare. The 3 methods used to capture mountain lions were cage traps, trained hounds, and cable restraints. The drugs used to immobilize mountain lions were either tiletam...

Many grassland habitats have disappeared or undergone substantial change worldwide and many obligatory grassland animal species have populations that are at risk of extinction. The Kori Bustard Ardeotis kori is the largest flying bird native to Africa and an open savanna specialist, but no research on the population ecology of the Kori Bustard in N...

In much of southern Africa, the leopard (Panthera pardus) is the last remaining large carnivore outside protected areas. We collected leopard scat (n = 82) opportunistically to determine the diet of leopards on small livestock farms and an adjacent national park in semi-arid Namaqualand, South Africa. We quantified prey availability using camera tr...

Intraspecific interactions shape animal social networks and regulate population dynamics. Species with solitary life histories rely on communication cues for population regulation, especially olfaction for many terrestrial mammals. Increasing evidence shows complex social structures among presumably solitary species and although social factors may...

Mitigating human-caused mortality for large carnivores is a pressing global challenge for wildlife conservation. However, mortality is almost exclusively studied at local (within-population) scales creating a mismatch between our understanding of risk and the spatial extent most relevant to conservation and management of wide-ranging species. Here,...

Although cheetahs Acinonyx jubatus were once widespread in the Horn of Africa, their presence in Somaliland has not been confirmed since 2010, and they have been presumed extirpated in recent years. During 2021–2022 the Cheetah Conservation Fund and the Ministry of Environment and Climate Change in Somaliland carried out two rapid surveys in the Aw...

In a recent Correspondence to Nature Ecology & Evolution, Gopalaswamy et al. are critical of the reintroduction of cheetahs into India, referring broadly to ecological, genetic and disease risks they feel have not been considered in replacing Asiatic cheetahs with the southern African sub-species. They further assert that three claims made in India...

Simple Summary We investigated the behavioral responses of five African ungulates to cheetah reintroduction in a semi-arid system affected by bush encroachment. Visitation rates, duration of stay, and activity patterns of ungulates at waterholes were compared with and without cheetah presence. During cheetah presence, visits to waterholes were rare...

Precise and accurate estimates of population size are fundamental to the study and conservation of wildlife. Identification of individual animals is often required to obtain such estimates, yet manual classifications by human observers induce bias, which can propagate across long-term datasets or large spatial scales. Pattern recognition algorithms...

Bush encroachment is a habitat change phenomenon that threatens savanna and grassland ecosystems worldwide. In Africa, large carnivores in bush encroached landscapes must adjust to increasing woody plant cover and biomass, which could affect predation success at multiple stages through complex and context-dependent pathways. We highlight, interpret...

Context Habitat loss and alteration affect wildlife populations worldwide. Bush encroachment alters landscapes and threatens arid and semi-arid grasslands, but its effects on predator–prey relationships and carnivore community ecology are not well understood. Predation strategies of large predators, for example high-speed pursuits versus ambush fro...

Flashing lights can work as an effective visual deterrent to protect livestock in kraals at night against wild carnivores.

The ecology of wildlife in remote arid regions with free-range livestock farming activities remains largely unexplored. We studied the temporal activity patterns of African leopards (Panthera pardus) in relation to prey in Namaqualand, South Africa, a semi-desert ecosystem with extensive livestock farming and a protected area. Camera trapping in wi...

Scent‐marking sites may facilitate interspecific information gathering and could help to minimise the risk of encounter with interspecific competitors. Recent evidence from South Africa shows that cheetahs avoid dominant predators at scent‐marking sites, which may delay or inhibit intraspecific communication in cheetahs. However, little is known on...

In press

Dens are important for species that need to survive and reproduce during harsh winters. Brown bears (Ursus arctos) in Romania, listed by the European Union as a population of concern, use dens for several months each year. To date, few quantitative assessments of denning habitat have been carried out for this population or others in Europe. In 2008...

The use of livestock guarding dogs (LGDs) has been widely advocated as a responsible tool for reducing livestock predation and conserving wildlife. However, their hidden ecological costs have rarely been investigated. We analysed scats (n = 183) from six LGDs and visited Global Positioning System (GPS) location clusters (n = 352) from nine GPS-coll...

Background: Wild carnivores living alongside humans and domestic animals are vulnerable to changes in the infectious disease dynamics in their populations. The aims of this study were to determine the prevalence and diversity of selected tick-borne pathogens (TBPs) of veterinary and/or zoonotic concern in wild populations of caracals (Caracal cara...

Wildlife agencies are generally tasked with managing and conserving species at state and local levels simultaneously. Thus, it is necessary for wildlife agencies to understand basic ecological processes of a given species at multiple scales to aid decision making at commensurately varied spatial and behavioral scales. Mountain lions (Puma concolor)...

The caracal Caracal caracal is the largest of Africa’s small felids (<20kg). Across much of Africa, particularly where larger predators have been extirpated, caracal are one of the main carnivores contributing to livestock predation. Caracal dietary studies are outdated, typically have small sample sizes and have mainly relied on scat analysis. We...

Many predators specialize on one or several prey species that they select from the range of potential prey. Predator specialization on primary versus alternative prey is driven in part by encounter rates with prey and a predator’s habitat selection. Although habitat selection changes with behavioural state, this has not been well‐recognized in the...

Satellite telemetry is an increasingly utilized technology in wildlife research, and current devices can track individual animal movements at unprecedented spatial and temporal resolutions. However, as we enter the golden age of satellite telemetry, we need an in-depth understanding of the main technological, species-specific and environmental fact...

R-code for boosted beta regression (Fix acquisition rate). (R)

Covariate partial effects on the variability of the fix acquisition rate. (PDF)

Tagged individuals per species. (PDF)

Covariate partial effects on the variability of the Overall fix success rate. (PDF)

Trends in observed data. (PDF)

Global dataset for boosted beta regressions. (CSV)

Description of data fields in S1 Data. (CSV)

Satellite telemetry articles published. (PDF)

Distribution of response variables and covariates. (PDF)

Unit purchase and operation costs. (PDF)

R-code for boosted beta regression (Overall fix success rate). (R)

Standardized data collection questionnaire. (PDF)

Satellite telemetry evaluations. (PDF)

Habitat characteristics associated with species occurrences represent important baseline information for wildlife management and conservation, but have rarely been assessed for countries recently joining the EU. We used footprint tracking data and landscape characteristics in Romania to investigate the occurrence of brown bear (Ursus arctos), gray...

Cheetah (Acinonyx jubatus) populations are subjected to a variety of complex, interacting anthropogenic and natural pressures. Understanding the causes of population decline is essential for being able to develop management strategies aimed at arresting the decline or reversing negative trends. Population Viability Analysis (PVA) uses computer mode...

Preservation and protection of land have been common means to achieve species conservation, but could be argued to have limited effectiveness for wide-ranging species, such as the cheetah (Acinonyx jubatus), that live predominantly outside protected areas (PAs). Some regions outside PAs are reported to have higher cheetah densities than PAs because...

The cheetah has experienced a dramatic decline in its distribution, with an adult and adolescent population of 7100 individuals remaining in the wild. Southern and eastern Africa have the largest populations, whereas west, central, and northern Africa have considerably smaller populations as a regional total. In Asia cheetahs are critically endange...

Considerable research has been conducted on cheetah ecology. Cheethas can exist in a wide variety of habitats from thick shrub to open grassland, and habitat selection is based on a variety of factors, including visibility, prey density, and avoidance of competitively superior predators. Cheetahs naturally occur at low densities and require a prey...

Live capture, tagging, and sampling of free-ranging animals are important means of acquiring health, genetic, and ecological data for wildlife conservation and management. We summarize best-practice procedures for capture, anesthesia, handling, sample collection, and marking of cheetahs. In all capture events involving anesthesia, data collection s...

There is an ever increasing and bewildering array of statistical and mathematical modelling techniques in conservation management of terrestrial wildlife. These quantitative techniques have been utilized mostly for wildlife management in North America and Europe, but are increasingly applied to African species including cheetah (Acinonyx jubatus)....

The potential for strong competition among small sympatric carnivores results in a need for coexistence strategies whereby competitors partition along spatial, temporal and dietary axes as a means to reduce ecological overlaps. We determined spatial and temporal partitioning patterns of a guild of small African carnivores: the African wildcat Felis...

Previous studies showed that the likelihood of a bear becoming a nuisance and thus being removed from a population (i.e., relocated or killed) depends on numerous factors such as natural food supply, sex, age, and reproductive status. Distances from a bear's home range and activity centers to confl ict zones such as towns, roads, and trails used by...

SUMMARY Technological advancements in remote sensing and telemetry provide opportunities for assessing the effects of expanding extractive industries on animal populations. Here, we illustrate the applicability of resource selection functions (RSFs) for modelling wildlife habitat selection on industrially-disturbed landscapes. We used grizzly bears...

Background Overexploitation and persecution of large carnivores resulting from conflict with humans comprise major causes of declines worldwide. Although little is known about the interplay between these mortality types, hunting of predators remains a common management strategy aimed at reducing predator-human conflict. Emerging theory and data, ho...

Increasing global demands have resulted in widespread proliferation of resource extraction. Scientists are challenged to develop environmental mitigation strategies that meet societal expectations of resource supply, while achieving minimal disruption to sensitive “wilderness” species. We used GPS collar data from a 9-year study on grizzly bears (U...

Industrial developments and reclamation change habitat, possibly altering large carnivore food base. We monitored the diet of a low-density population of grizzly bears occupying a landscape with open-pit coal mines in Canada. During 2009–2010 we instrumented 10 bears with GPS radiocollars and compared their feeding on reclaimed coal mines and neigh...

Advancements in GPS radiotelemetry allow collection of vast data for a variety of species including those for which direct observations are typically not feasible. Predicting behavior from telemetry data is possible, but telemetry fix rate can influence inferences, and animal behavior itself can affect fix success. We use multinomial regression to...

Prey consumption forms a large part of prey-handling time, and knowledge of where prey is ingested can inform management of predator–prey systems. Safeguarding habitats that promote prey consumption could enhance populations of facultative or obligate carnivores of conservation concern. We investigated habitat characteristics at 124 sites where rad...

On human-used landscapes, animal behavior is a trade-off between maximizing fitness and minimizing human-derived risk. Understanding risk perception in wildlife can allow mitigation of anthropogenic risk, with benefits to long-term animal fitness. Areas where animals choose to rest should minimize risk from predators, which for large carnivores typ...

Wildlife-human conflicts occur wherever large carnivores overlap human inhabited areas. Conflict mitigation can be facilitated by understanding long-term dynamics and examining sex-structured conflict patterns. Predicting areas with high probability of conflict helps focus management strategies in order to proactively decrease carnivore mortality....

Reintroductions of large carnivores into enclosed reserves that confine movements may fail due to intensive intra-guild interspecific conflict. To assess conflict potential, in winter 2006 we used direct observations aided by radio-tracking to focally monitor continuously one female cheetah with cub (Acinonyx jubatus), a female leopard (Panthera pa...

Diet and environment impact the composition of mammalian intestinal microbiota; dietary or health disturbances trigger alterations in intestinal microbiota composition and render the host susceptible to enteric pathogens. To date no long term monitoring data exist on the fecal microbiota and pathogen load of carnivores either in natural environment...

Autocorrelation has been viewed as a problem in telemetry studies because sequential observations are not independent in time or space, therefore violating assumptions for statistical inference. Yet nearly all ecological and behavioural data are autocorrelated in both space and time. We argue that there is much to learn about the structure of ecolo...

Gut physiology, host phylogeny, and diet determine the composition of the intestinal microbiota. Grizzly bears (Ursus arctos horribilis) belong to the Order Carnivora, yet feed on an omnivorous diet. The role of intestinal microflora in grizzly bear digestion has not been investigated. Microbiota and microbial activity were analysed from the feces...

This study compares two methods of estimating the density of three ungulate species: Kirk’s dik-dik, impala and common zebra, in a dry savannah ecosystem. Fixed strip width and distance sampling involving direct animal counts were used in parallel, and tested for bias and precision in two habitats. Distance sampling was the method that achieved a b...

Two methods of estimating large carnivore prey density, based on pellet counts, were applied in autumn 2004 at preferential feeding sites of ungulates on two hunting grounds in Vrancea Carpathian mountain range, Romania, and analyzed in comparison. Density estimates were calculated with both methods and showed that red deer (Cervus elaphus L.) and...