Free-ranging domestic cats (Felis catus) are globally distributed invasive carnivores. While recognition of their impacts has focused on consumption of vertebrates, increasing evidence suggests that they also consume large numbers of invertebrate species. Given the ongoing concern over invertebrate population declines across the planet, we compiled and analyzed a global database of invertebrate species reported in studies of cat diet. Despite making up >90% of all terrestrial animal species, invertebrates constituted only 7% of the >2000 species we identified as eaten by cats. However, when invertebrates were recorded in cat dietary studies, few were identified to species-level. Four of the 148 invertebrate species we reported to be eaten by cats are considered threatened by the IUCN, but cat predation is not recognized as a threat in their IUCN accounts. IUCN accounts do report cat predation as a threat for 48 invertebrate species of conservation concern, however none of these appear in our database. Insects (especially beetles) constituted similar to 80% of the 148 invertebrate species reported in cat dietary studies, with crustacean, arachnid, centipede, snail and slug, and millipede species occurring less frequently. Our results add to the growing consensus that cats consume a wide variety of invertebrate species and that they depredate more invertebrate species than is currently recognized. We recommend more cat dietary studies using eDNA (complemented by a more comprehensive eDNA library of invertebrate species), more autecological studies of threatened invertebrate species, and studies of responses of invertebrates to eradication or exclusion of feral cats.

Free-ranging domestic cats (Felis catus) are recognized as invasive and efficient predators on islands, although their impact on continental wildlife remains poorly understood. Predation behavior and space use are key indicators for estimating the influence of these felines on prey populations through direct killings and sublethal effects (landscape of fear). Previous work highlighted-and debated-the importance of biological (sex, age) and environmental (habitat type) factors as well as owner-related habits (feeding, play, hygiene) in shaping hunting and roaming behaviors. However, the influence of individual behavioral characteristics, known as personality, remains largely unexplored. In this study conducted in a suburban area south of Paris, we monitored 23 domestic cats using combined GPS and animal-borne camera devices (or "kittycams") between March and May 2025. Cat predation behavior was analyzed using a detailed ethogram, and space use was studied through two parameters: core range (aKDEc50) and full range (aKDEc95). Although additional data would certainly strengthen our conclusions, our results already reveal that personality affects both range size and hunting propensity. More precisely, cats with high levels of agreeableness and neuroticism have smaller range sizes and hunt less than other individuals. Moreover, animal-borne cameras are far more reliable than the prey-report method to assess predation events and prey diversity, as only one prey was discovered of the 31 caught in total. These results pave the way for tailored, effective, and ethical management measures to mitigate the impact of domestic cats on wildlife.

We developed a method to assess bird species’ vulnerability to predation by free-ranging domestic cats (Felis catus) using prey preference data from citizen science in Italy and the United Kingdom. By combining species traits and geographical range, we trained random forest models to predict prey preferences and identify missing prey species. Our analysis showed that including the geographical range significantly improved model accuracy and reduced prey detectability issues. Cross-validation confirmed that models trained in one country could effectively predict prey preferences in another, allowing for broader application. Shapley additive explanations values analysis revealed that small, generalist birds with a low hand-wing index and large geographical range were most likely to be preyed upon. We used these models to create vulnerability lists for United States bird species, which showed moderate overlap but high consistency with previous studies, highlighting their robustness. These results showed that this method could thus be used to improve our understanding of cat predation and inform targeted conservation strategies, with better citizen science data being crucial for further improvements.

ABSTRACT The Red Fox (Vulpes vulpes) can be hunted as a game species. It may also be listed as a “species likely to cause damage” (ESOD – the acronym in French), for public health reasons among others. Conversely, benefits linked to the presence of foxes are also put forward, such as the predation of rodents carrying zoonotic agents. In this context, ANSES was asked to: (1) list the zoonoses present in France for which foxes play an epidemiological role, (2) identify other public health impacts associated with changes in fox populations, (3) explain the relative importance of the effects of changes in fox populations for humans and/or the environment, (4) analyse the feasibility of a cost‐benefit analysis (CBA) of the prevention and impacts associated with these zoonoses. In France, the fox is a source of zoonotic pathogens, with a major role for Echinococcus multilocularis, a parasite for which the fox is the main source of environmental contamination. However, reducing fox populations does not reduce the risk of transmission of E. multilocularis to humans or domestic animals, and may even have the opposite effect to the one intended. The main levers for action are those relating to exposure to environmental contamination. The fox is part of complex trophic networks, in which its specific role in regulating prey populations is impossible to determine because (i) several predators share the same prey, with a variable role for the fox among the predators, (ii) the dynamics of prey populations is also conditioned by factors other than predation. The relationship between the abundance of rodents and the risk of disease for humans has not been demonstrated either, due to the complexity of the trophic and epidemiological networks, their highly probable variability from one ecosystem to another, and the multiplicity of hosts. As a result, the data currently available does not allow any conclusions to be drawn about the epidemiological role of the fox as a predator of rodents hosting zoonotic agents. Finally, there is no public health justification for culling foxes, particularly for ESOD classification, except in the very specific and localised context of the fight against bovine tuberculosis, for which the selective culling of foxes in and around the livestock buildings of a domestic outbreak has been proposed. In addition, the expertise concluded to the feasibility of a CBA targeted at assessing the burden of alveolar echinococcosis and measures to prevent its transmission. The feasibility study shows the partial nature of a CBA targeting zoonoses, without taking into account other roles played by the fox in the ecosystem.

Effective conservation of biodiversity depends on the successful management of wildlife populations and their habitats. Successful management, in turn, depends on our ability to understand and accurately forecast how populations and communities respond to human-induced changes in their environments. However, quantifying how these stressors impact population dynamics remains challenging. Another significant hurdle at this interface is determining which quantitative approach(es) are most appropriate given data types, constraints and the intended purpose. Here, we provide a cross-taxa overview of key methodological approaches (e.g., matrix population models) and model elements (e.g., energetics) that are currently used to model the effects of anthropogenic disturbance on wildlife populations. Specifically, we discuss how these modelling approaches differ in their key assumptions, in their structure and complexity, in the questions they are best poised to address and in their data requirements. Our intention is to help overcome some of the methodological biases that might persist across taxonomic specialisations, identify new opportunities to address existing modelling challenges and improve scientific understanding of the direct and indirect impacts of anthropogenic disturbance. We guide users through the identification of appropriate model configurations for different management purposes, while also suggesting key priorities for model development and integration.

Co-evolutionary relationships associated with biogeographical context mediate the response of native prey to introduced predators, but this effect has not yet been demonstrated for domestic cats. We investigated the main factors influencing the vulnerability of prey species to domestic cat Felis catus predation across Australia, Europe and North America, where domestic cats are introduced. In addition to prey data from empirical records, we used machine-learning models to compensate for unobserved prey in the diet of cats. We found continent-specific patterns of predation: birds were more frequently depredated by cats in Europe and North America, while mammals were favoured in Australia. Bird prey traits were consistent across continents, but those of mammalian prey diverged, notably in Australia. Differences between prey and non-prey species included mass, distribution, and reproductive traits, except in Australian mammals where there was no evidence for a relationship between mass and the probability of being prey. Many Australian mammal prey also have a high extinction risk, emphasizing their vulnerability compared to European and North American counterparts. Our findings highlight the role of eco-evolutionary context in assessing predation impacts and also demonstrate the potential for machine learning to identify at-risk species, thereby aiding global conservation efforts to reduce the negative impacts of introduced predators.

Abstract Domestic cats' varying home range sizes are connected to their impact on wildlife. Most of the previous studies suffered from lacking causality or small sample sizes. To overcome these limitations, we conducted a comprehensive study involving 55 owned domestic cats in a French suburban area where each cat was monitored during one or nine sessions over 5 years and all four seasons. We tracked the cats using GPS technology while controlling for the device used for monitoring, climatic conditions, environmental changes, and their degree of roaming. Using linear mixed‐effect models, we found that age and sex significantly predict home range size. Younger cats tend to have larger home ranges and male cats have larger home ranges compared to females. We also found that the device used during the monitoring influenced the size of the home range. Surprisingly, climatic conditions, surrounding environment and degree of roaming had no significant impact. When considering our models, most of the variability in home range size was due to random effects that accounted for the identity of cats which were monitored one or more times. Therefore, a deeper understanding of intrinsic and extrinsic factors influencing home range size in domestic cats is crucial. This includes investigating individual behavior, breed‐specific traits, and the role of owner care but also reassessing management solutions for reducing cat roaming and not only focusing on restrictive ones. Identifying these factors will enable the development of more effective management.

Prey–predator models are frequently developed to investigate trophic webs and to predict the population dynamics of prey and predators. However, the parameters of these models are often implemented without empirical data and may even be chosen arbitrarily. Commonly, only a few parameters are tested regarding their sensitivity and it is rare to read about the comparison between different prey–predator models (i.e. predation function structure). Here, we propose a method to compare four prey–predator models designed for two populations. We then apply this method to select the more biologically plausible one to model a simplified agricultural trophic system, including one predator compartment (the red fox Vulpes vulpes) and one prey group compartment (small mammals). These models are based on four Holling functional responses for the predation interaction and take the prey intrinsic growth rate into account through a Verhulst logistic function. Most parameters’ values (like attack rates or growth rates) were calculated from field data or based on literature review. We then used Sobol indices to conduct parameter exploration around mean parameter values to investigate and compare the model dynamics responses. Our first results showed that under our assumptions, the two most relevant models for our case study are the saturated Holling I and II models. We were also able to discriminate that among the 6 scaled parameters that vary, the model outputs are particularly sensitive to four of them (κ: saturation rate of the environment, Tr1: characteristic intrinsic decay time of the predators, Tc: characteristic growth time of the predator via the predation on the prey and λ: saturation rate of a predator’s stomach per time unit) and much less sensitive to two others (Tr2: characteristic intrinsic growth time of the prey and Ta: characteristic decay time of the prey due to the predation). These first encouraging results open the way for the next step, which will be to adapt this model construction to more complex prey–predator systems, with several predator and/or several prey compartments.

Seabirds have been particularly affected by invasive non‐native species, which has led to the implementation of numerous eradication campaigns for the conservation of these keystone and highly vulnerable species. Although the benefits of eradication of invasive non‐native species for seabird conservation have been demonstrated, the recovery kinetics of different seabird populations on islands after eradication remains poorly evaluated. We conducted long‐term monitoring of the number of breeding pairs of seven seabird species on a small atoll, Surprise Island, New Caledonia (southwestern tropical Pacific). Marine avifauna of the island were surveyed yearly 4 years before to 4 years after rodent eradication (conducted in 2005), and we conducted multiple one‐time surveys from ∼10 years before and ∼15 years after eradication. We sought to determine how different seabird species responded to the eradication of invasive rodents in an insular environment. Three species responded positively (two‐ to 10‐fold increase in population size) to eradication with differences in lag time and sensitivity. The number of breeding pairs increased (effect sizes = 0.49–0.95 and 0.35–0.52) for two species over 4 years post‐eradication due to immigration. One species had a longer (at least 5 years) response time than all others; breeding pairs increased for over 10 years after eradication. Long‐term sampling was necessary to observe the responses of the seabird populations on the island because of the delayed response of a species to eradication not visible in the first years after eradication. Our results confirmed the positive effects of eradication of invasive non‐native species on seabirds and emphasize the importance of mid‐ and long‐term pre‐ and posteradication surveys to decipher the mechanisms of seabird recovery and confirm the benefits of eradication for conservation purposes.

Abstract Pitfall traps are frequently used to capture ground‐dwelling arthropods, particularly beetles, ants and spiders. The capture efficiency of a pitfall trapping system strongly depends on the number and opening size of traps, how traps are distributed over the sampling area (spatial arrangement) and the movement characteristics of arthropods. We use numerical simulations for a single species to analyse the trap count patterns that emerge from these variables. Arthropod movement of individuals is modelled as correlated random walks, with multiple traps placed over an area, and catches are simulated as individual interaction with traps. We consider four different types of spatial arrangements of traps across a homogeneous landscape: grid (i.e. rectangular array), transect, nested‐cross and randomised. We contextualise our results by considering the locomotion of Pterostichus melanarius, a highly active carabid beetle often serving as a biocontrol agent for the suppression of pest insects and weeds. By simulating the trapping of randomly moving ground‐dwelling arthropods, we show that there is an optimal inter‐trap separation distance (trap spacing) that maximises captures, that can be expressed using exact formulae in terms of trap opening sizes, sampling area and trap number. Moreover, for the grid and nested‐cross arrangements, larger trap spacing to maximise spatial coverage over the whole sampling area is suboptimal. Also, we find that over a large sampling area, there is a hierarchical order for spatial arrangements in relation to capture efficiency: grid, randomised, transect, followed by the nested‐cross. However, over smaller sampling areas, this order is changed as the rate at which trap counts accumulate with trap number varies across arrangements—eventually saturating at different levels. In terms of movement effects, capture efficiency is maximised over a narrow diffusive range and does not depend strongly on the type of spatial arrangement—indicating an approximate optimal mode of arthropod activity, i.e. rate of spread. Our approach simultaneously considers several important experimental design aspects of pitfall trapping providing a basis to optimise and adapt sampling protocols to other types of traps to better reflect their various purposes, such as monitoring, conservation or pest management.

The domestic cat, Felis catus, is one of the most popular and widespread domestic animals. Because domestic cats can reach high population densities and retain at least some tendency to hunt, their overall impact on wildlife can be severe. Domestic cats have highly variable predation rates depending on the availability of prey in their environment, their owners' practices, and individual cat characteristics. Among these characteristics, cat personality has recently been hypothesized to be an important factor contributing to variations in the hunting activity of cats. In this study, we surveyed 2508 cat owners living in France about their cats' personalities, using the Feline Five personality framework, and the frequency with which cats bring home prey. Personality traits were analyzed using factor analysis and related to predation frequency using cumulative logit models. For both birds and small mammals, cats with high levels of extraversion or low levels of neuroticism had significantly higher frequencies of prey return. Owners whose cats had low levels of agreeableness or high levels of dominance reported a significantly lower frequency of bird return. Personality differences therefore seem to contribute to the high variability in predation rates among domestic cats. We also found that the owner-reported prey return frequencies were significantly higher for cats spending more time outdoors, for non-pedigree cats, and for owners living in rural or suburban areas as opposed to urban areas. By contrast, we did not detect an effect of cat sex or age on their reported prey return rates.

Seabirds are one of the most threatened bird groups on the planet, with approximately 30% at risk of extinction. The primary cause of population decline and extinction are non-native species introduced to islands, such as mammals, and which subsequently prey on seabirds or damage habitats. These “invasive species” are impacting 46% of seabird species and over 170 million individual seabirds globally. Of seabirds impacted, 66% are currently listed as globally threatened on the International Union for the Conservation of Nature (IUCN) Red List, highlighting the urgent need to remove the threat of invasive species to prevent seabird extinctions. In this chapter we discuss these impacts in detail, including a brief history of invasion processes that have led to this global problem. We also describe emerging invasive species threats and investigate how climate change will further exacerbate the impacts of invasive species on seabirds. We conclude this chapter with a discussion on the successful management and reduction of invasive species, which have resulted in substantial conservation gains for seabirds and whole island ecosystems worldwide.

Free-ranging cats ( Felis catus ) are globally distributed invasive carnivores that markedly impact biodiversity. Here, to evaluate the potential threat of cats, we develop a comprehensive global assessment of species consumed by cats. We identify 2,084 species eaten by cats, of which 347 (16.65%) are of conservation concern. Islands contain threefold more species of conservation concern eaten by cats than continents do. Birds, reptiles, and mammals constitute ~90% of species consumed, with insects and amphibians being less frequent. Approximately 9% of known birds, 6% of known mammals, and 4% of known reptile species are identified in cat diets. 97% of species consumed are <5 kg in adult body mass, though much larger species are also eaten. The species accumulation curves are not asymptotic, indicating that our estimates are conservative. Our results demonstrate that cats are extreme generalist predators, which is critical for understanding their impact on ecological systems and developing management solutions.

Articles about doing a PhD tend to focus on the difficulties faced by research students. Here we argue that the scientific community should also highlight the positive elements of the PhD experience.

The domestic cat (Felis catus) is one of the most abundant predators and a serious threat to many wildlife species. While a large body of literature explores the number and diversity of individuals depredated by pet cats, the drivers of predation have been investigated much less. Although the environment of the cat, the owner behavior, and the intrinsic characteristics of the cat itself could impact the predatory behavior and should therefore not be considered separately, very few studies simultaneously take these three components into account. In this study, we explored 21 concomitant drivers of predation by pet cats linked to these three components at different scales, to explain the owners-reported frequencies of captured birds, mammals, and herpetofauna. Among the 1,400 sociological surveys received from cat owners, 740 reliable answers were analyzed. Results suggest that the owners-reported prey capture frequencies were strongly influenced by the environment, especially by factors relating to urbanization. Rural owners were around two times more likely to report more frequent predation events than owners living in urban areas, whatever the group of prey studied. As a result, the urban habitat variable had the highest impact on predation in this study. An experimental approach would be beneficial to identify the factors influencing the reported predation rates, which are causally related to the number of wild animals killed.

Bird damage, from sowing to crop establishment, is an important issue for farmers in many parts of the world. However, reliable and cost-effective solutions remain elusive because management tools and research on the subject are limited. The spatial variability of damage across landscapes and the adaptative behaviour of birds create further challenges. Additionally, the issue must be tackled at the landscape scale and involve a variety of stakeholders with conflicting interests and objectives. We summarize some of the challenges and opportunities identified to face these difficulties and address four major research directions for operational solutions including 1) crop damage assessment, 2) methods and tools development at the landscape scale, 3) coordination of stakeholders, and 4) pest bird ecology in agroecosystems. More fundamentally, we address the question of large-scale ecological dynamics that can explain changing damage patterns such as the recent observations of increased damage in Europe. Despite the impact to the agricultural sector, research effort to understand vertebrate pest damage is still modest. We advocate for the creation of networks to share knowledge and feedback and engages multiple stakeholders, including ecological and agricultural researchers, farmers, and policy makers.

The rate of biological invasions is growing unprecedentedly, threatening ecological and socioeconomic systems worldwide. Quantitative understandings of invasion temporal trajectories are essential to discern current and future economic impacts of invaders, and then to inform future management strategies. Here, we examine the temporal trends of cumulative invasion costs by developing and testing a novel mathematical model with a population dynamical approach based on logistic growth. This model characterises temporal cost developments into four curve types (I - IV), each with distinct mathematical and qualitative properties, allowing for the parameterization of maximum cumulative costs, carrying capacities and growth rates. We test our model using damage cost data for eight genera ( Rattus , Aedes , Canis , Oryctolagus , Sturnus , Ceratitis , Sus and Lymantria ) extracted from the InvaCost database – which is the most up-to-date and comprehensive global compilation of economic cost estimates associated with invasive alien species. We find fundamental differences in the temporal dynamics of damage costs among genera, indicating they depend on invasion duration, species ecology and impacted sectors of economic activity. The fitted cost curves indicate a lack of broadscale support for saturation between invader density and impact, including for Canis , Oryctolagus and Lymantria , whereby costs continue to increase with no sign of saturation. For other taxa, predicted saturations may arise from data availability issues resulting from an underreporting of costs in many invaded regions. Overall, this population dynamical approach can produce cost trajectories for additional existing and emerging species, and can estimate the ecological parameters governing the linkage between population dynamics and cost dynamics.