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Humans have transformed most landscapes across the globe, forcing other species to adapt in order to persist in increasingly anthropogenic landscapes. Wide-ranging solitary species, such as wild felids, struggle particularly in such landscapes. Conservation planning and management for their long-term persistence critically depends on understanding what determine survival and what are the main mortality risks. We carried out the first study on annual survival and cause-specific mortality of the European wildcat with a large and unique dataset of 211 tracked individuals from 22 study areas across Europe. Furthermore, we tested the effect of environmental and human disturbance variables on the survival probability. Our results show that mortalities were mainly human-caused, with roadkill and poaching representing 57% and 22% of the total annual mortality, respectively. The annual survival probability of wildcat was 0.92 (95% CI = 0.87–0.98) for females and 0.84 (95% CI = 0.75–0.94) for males. Road density strongly impacted wildcat annual survival, whereby an increase in the road density of motorways and primary roads by 1 km/km2 in wildcat home-ranges increased mortality risk ninefold. Low-traffic roads, such as secondary and tertiary roads, did not significantly affect wildcat's annual survival. Our results deliver key input parameters for population viability analyses, provide planning-relevant information to maintain subcritical road densities in key wildcat habitats, and identify conditions under which wildcat-proof fences and wildlife crossing structures should be installed to decrease wildcat mortality., This research was funded by: the German Federal Ministry of Transport and Digital Infrastructure (BMVI) as part of the mFund project “WilDa—Dynamic Wildlife–Vehicle Collision warning, using heterogeneous traffic, accident and environmental data as well as big data concepts” grant number 19F2014B; the Deutscher Akademischer Austauschdienst (DAAD) Research Grants, Short-Term Grants, 2020 (57507441); the Deutsche Wildtier Stiftung (DeWiSt). The data from Cabañeros National Park were collected in the frame of the project OAPN 352/2011 funded by Organismo Autónomo Parques Nacionales. MM was supported by a research contract Ramón y Cajal from the MINECO (RYC-2015-19231). FDR was supported by a postdoctoral contract funded by the University of Málaga through the grants program “Ayudas para la Incorporación de Doctores del I Plan Propio de Investigación de la Universidad de Málaga (Call 2019)”. PM was supported by UIDB/50027/2020 with funding from FCT/MCTES through national funds.

Optimal foraging theory predicts that in situations of high prey abundance, predators will select the largest ones if the cost of capture is similar. This relationship is not clear in species of large owls. We aimed to evaluate the selection by the Eagle Owl (Bubo bubo) of different body sizes of a profitable prey, the European Rabbit (Oryctolagus cuniculus). Evaluations were made in a semi-natural rabbit population with high rabbit availability (Los Melonares), and in two natural populations with different abundances of rabbit (low to high). In Los Melonares, we compared the size distribution of rabbits in the owl diet with the body size distribution of the rabbit population. In the natural populations, we compared the size of the rabbits in the owl diet with the abundance of rabbits. Results from Los Melonares showed that the Eagle Owl positively selected smaller rabbits (< 300 g) regardless of rabbits size distribution within the population throughout the year but such selection was only significant when the abundance of rabbits reached the highest levels. On the contrary, owls avoided rabbits belonging to the largest size class (> 900 g) throughout the year, being not significant in winter with low abundance of rabbits. In natural populations, smaller rabbits were included in the owl diet more frequently when rabbit abundance increased. Thus, Eagle Owl seemed to select the smallest rabbits, probably due to their higher vulnerability, ease of capture, their predictable location in areas surrounding warrens, and the lesser effort required to handle, consume and deliver to nestlings.

The physiological significance of biometric body condition indices (bBCI) is poorly understood. We hypothesized that bBCI are composite metrics of nutritional physiology, physical fitness and health. To test this hypothesis, we first compared the performance of eight bBCI, using 434 Southern European carnivores from six species as a model system; and then identified, by non-destructive methods, the hematology and serum biochemistry correlates of three selected bBCI. Fulton’s K Index, Major Axis Regression Residuals and Scaled Mass Index were the only bBCI insensitive to the effect of sex and age. The most informative physiological parameters in explaining the variation of these bBCI were the albumin (Effect Size (ES) = − 1.66 to − 1.76), urea (ES = 1.61 to 1.85) and total bilirubin (ES = − 1.62 to − 1.79). Hemoglobin and globulins (positive) and cholesterol (negative) were moderately informative (0.9, This work was supported by Junta de Comunidades de Castilla-La Mancha [Project PREG-05-23], Spanish Ministry of Science and Innovation and European Union-FEDER funds [Project CGL2009-10741]; Organismo Autónomo Parques Nacionales [Project OAPN352/2011]; Empreendimentos Eólicos do Vale do Minho S.A. and Associação para a Conservação do Habitat do Lobo Ibérico (ACHLI); Fundação para a Ciência e Tecnologia [grants SFRH/BPD/116596/2016 to N.S. and SFRH/BD/144087/2019 to M.N. and UID/BIA/50027/2019 to P.M.]; FCT/MCTES, through national funds, and the co-funding by the FEDER, within the PT2020 Partnership Agreement and Compete 2020 [cE3c—UIDB/00329/2020]; Juan de la Cierva research contracts from Ministerio de Ciencia e Innovación, Funder Id: 10.13039/501100004837 from the Spanish Ministry of Economy, Industry and Competitiveness [FJCI-2015-24949 to F.D.R.]; and the European Union H2020 [Project H2020 VACDIVA 862874 to J.A.B.].

Competition is a widespread interaction among carnivores, ultimately manifested through one or more dimensions of the species' ecological niche. One of the most explicit manifestations of competitive interactions regards spatial displacement. Its interpretation under a theoretical context provides an important tool to deepen our understanding of biological systems and communities, but also for wildlife management and conservation. We used Bayesian multispecies occupancy models on camera‐trapping data from multiple sites in Southwestern Europe (SWE) to investigate competitive interactions within a carnivore guild, and to evaluate how species' ecological traits are shaping coexistence patterns. Seventeen out of 26 pairwise interactions departed from a hypothesis of independent occurrence, with spatial association being twice as frequent as avoidance. Association behaviors were only detected among mesocarnivores, while avoidance mainly involved mesocarnivores avoiding the apex predator (n = 4) and mesocarnivore‐only interactions (n = 2). Body mass ratios, defined as the dominant over the subordinate species body mass, revealed an important negative effect ( βˆ=−0.38;CI95=−0.81𝑡𝑜−0.06 ) on co‐occurrence probability, and support that spatially explicit competitive interactions are mostly expressed by larger species able to dominate over smaller ones, with a threshold in body mass ratios of ~4, above which local‐scale intraguild coexistence is unlikely. We found a weak relationship between pairwise trophic niche overlap and the probability of coexistence ( βˆ=−0.19;CI95=−0.58𝑡𝑜0.21 ), suggesting that competition for feeding resources may not be a key driver of competition, at least at the scale of our analysis. Despite local‐scale avoidance, regional‐scale coexistence appears to be maintained by the spatial structuring of the competitive environment. We provide evidence that SWE ecosystems consist of spatially structured competitive environments, and propose that coexistence among near‐sized species is likely achieved through the interplay of “facultative” and “behavioral” character displacements. Factors influencing carnivore coexistence likely include context‐dependent density and trait‐mediated effects, which should be carefully considered for a sound understanding of the mechanisms regulating these communities., This study was funded by research projects CGL2009‐10741, funded by the Spanish Ministry of Science and Innovation and EU‐FEDER, and OAPN 352/2011, funded by the Spanish Organismo Autónomo Parques Nacionales. P. Monterroso enjoyed a Ph.D. grant from the Fundação para a Ciência e a Tecnologia (FCT) (ref: SFRH/BD/37795/2007) and a postdoctoral fellowship by EU‐FEDER funds through the Operational Programme for Competitiveness Factors—COMPETE and by National Funds through FCT—Foundation for Science and Technology (ref: UID/BIA/50027/2013, POCI‐01‐0145‐FEDER‐006821). F. Díaz‐Ruiz enjoyed a research contract “Juan de la Cierva” (ref: FJCI‐2015‐24949) from the Spanish Ministry of Economy, Industry, and Competitiveness.

It is known that the garden dormouse Eliomys quercinus includes meat in its diet, however, it is unclear if scavenging is a widespread behaviour, as it is difficult to observe in the wild. Here, we document scavenging behaviour for the species based on direct evidence. We captured five garden dormice with live traps using dead baits, which were partially or totally consumed. Additionally, a camera-trap recorded how at least one garden dormouse visited and actively consumed the bait on 12 occasions during the study. These observations suggest that carrion may play an important role in the garden dormouse's diet, opening a new ecological unexplored topic for this species., This study was funded by projects TOPIGEPLA (Fundación BBVA Research Projects, 2014 call) and Movi-Topi (I + D National Plan Project, CGL2015-71255-P). F. Díaz-Ruiz was supported by a “Juan de la Cierva” research contract (Ministerio de Ciencia e Innovación, Funder Id: 10.13039/501100004837, FJCI-2015-24949) from the Spanish Ministry of Economy, Industry and Competitiveness.

Currently, there are naturalized populations of feral pigeon (Columba livia var. domestica) worldwide with an estimated global population between 165 and 330 million individuals. Feral pigeons are adapted to urban environments, creating problems related to human health, damage to architectural structures, unpleasant soiling, and foul odors. Thus, local governments usually implement measures to reduce feral pigeon populations in cities to a suitable size. We monitored a feral pigeon trapping campaign to investigate the use of cage traps as control method in residential zones. We analyzed efficiency (daily capture rate), effectiveness (defined as the number of feral pigeons captured relative to the total number of potential pigeon captures), animal welfare, selectivity (the proportion of captured feral pigeons in relation to the total number of captured animals), and the effect on feral pigeon abundance. All procedures were conducted in compliance with current European and Spanish legislation. Overall efficiency was 0.25 feral pigeons/trap-day, effectiveness was 22.5%, and selectivity was 99.7%. Over the study period, there was a decreasing trend in abundances. A significant decrease was found in the relative abundances of feral pigeons after 2 months of extractions, and population abundances remained low up to the end of the extraction period. The use of cage traps was a useful and effective method to reduce local feral pigeon populations in isolated urban areas with low building density in which the feral pigeon population has not yet reached high densities., F. Díaz-Ruiz was supported by a Juan de la Cierva postdoctoral contract (Ministerio de Ciencia e Innovación, Funder Id: 10.13039/501100004837, FJCI-2015- 24949) from the Spanish Ministry of Economy, Industry and Competitiveness.

Carnivores are elusive, nocturnal and scarce, hence, their detection is difficult. Camera trapping has become a powerful non-invasive technique for collecting information on such elusive species. Some of its major applications are species inventories and community monitoring. Some efforts have been recently devoted to standardize protocols for monitoring mammal communities in tropical areas. Nevertheless, there is a lack of standardization across studies for monitoring carnivore communities in temperate areas. We aimed to optimize camera-trapping protocols for monitoring mesocarnivore communities in Mediterranean areas, minimizing sampling effort to accurately estimate species richness. For this purpose, we assessed the effect of number of cameras, time they remain active, area covered and spatial arrangement on species richness estimates. We used between 50 and 60 camera-traps combined with generalist scent attractants in two national parks located in central Spain. We generated random sets of 5–40 cameras and evaluated the accumulated richness between 1 and 30 days since deployment. Generalized linear model analysis indicates that active days, number of cameras, covered area and study area best explained species richness. A minimum of 30 active cameras during 20 days were required for attaining the asymptotical species richness. A larger effort was required to detect all species in the study area with higher species richness (six vs. five species). These results agree with the effort required for obtaining at least one camera image of those species with the lowest detection rates. Scattered deployments required less effort (number of cameras) to reach an asymptote of species richness than clumped layouts, although differences were not significant. These findings can be used as guidelines for monitoring mesocarnivore communities with camera-traps in temperate areas, although particular monitoring requirements will depend on the community composition and density of mesocarnivore species present in a given study area., This study was funded by Organismo Autónomo Parques Nacionales, project OAPN 352/2011. F. Díaz‐Ruiz enjoyed a postdoctoral contract funded by the European Social Fund (ESF) and Junta de Comunidades de Castilla‐La Mancha (Operational Programme FSE 2007/2013). P. Monterroso was granted a postdoctoral fellowship by the project ‘Genomics Applied to Genetic Resources’ cofinanced by North Portugal Regional Operational Programme 2007/2013 (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF).

Cage-trapping is one of the control methods frequently used by hunters to remove red foxes (Vulpes vulpes) in Spain, although its low efficiency and selectivity have been frequently reported. We tested the effect of the combinations of two bait types (live/ dead) and two scent attractants (fox urine/valerian extract) in order to improve the efficiency and selectivity of cage traps in central Spain. The combination of live bait and fox urine increased the efficiency of cage traps to capture red foxes in comparison with live bait alone. None of the experimental treatments led to a significant reduction in the capture rate of non-Target species, selectivity levels were always low (0%-21%) and non-Target species were captured. In view of that, the burden of releasing captured non-Target animals depends ultimately on the trapper. For this reason, the use of cage traps is still questionable for managing foxes in Spain., Castilla-La Mancha Regional Government; code numbers 02-227/RN-52 and PREG-05-23.

[Context]: Camera trapping is commonly employed for studying carnivores because it provides better data than do other methods, and with lower costs. Increasing the probability of detecting the target species can reduce parameter uncertainty and survey effort required to estimate density and occurrence. Different methods, including attractants and baits, can be used to increase detectability. However, their efficacy has rarely been quantitatively assessed. [Aims]: To quantify the efficacy of scent and bait attractants to increase the detection probability of mesocarnivores by camera trapping. [Methods]: We tested two scent lures, valerian extract (Val) and lynx urine (LU), their combination (Val-LU), and a non-reward bait (i.e. not accessible to the animal), raw chicken, as carnivore attractants in two protected areas of central Spain. We used camera-trapping records under an occupancy-modelling framework to estimate attractant-specific detection probabilities for six mesocarnivore species, and quantified their effects by comparing these estimates with the baseline (i.e. no attractant) detectability. [Key results]: The weekly detection probability of four mesocarnivore species (red fox, Vulpes vulpes, stone marten, Martes foina, common genet, Genetta genetta, and Eurasian badger, Meles meles) significantly increased when Val-LU (between 0.11±0.07 and 0.67±0.05) or chicken (between 0.31±0.02 and 0.77±0.22) were used as attractant, when compared with baseline detectability (between 0.01±0.02 and 0.29±0.05). Although rarely, wildcats (Felis silvestris) were mostly detected with Val-LU. The probability of detecting a species after k sampling occasions (7 days each) where it was present was highly improved with both Val-LU and chicken for all species (e.g. from 0.20 to 0.98 after four sampling occasions with chicken for the stone marten). Both attractants reduced the sampling time required to ascertain that a species was absent to between 42% and 15% of baseline values. [Conclusions]: The tested attractants greatly improved the detectability of most Iberian mesocarnivores. Although chicken was preferable for some species such as stone marten, Val-LU is most efficient for detecting the whole mesocarnivore community, including rare species such as wildcats. [Implications]: Attractant selection in studies using non-invasive detection methods must be supported by quantitative assessment of the detection probability associated to each attractant. Researchers must choose those attractants best fitting target species and study aims., This study was funded by Organismo Autónomo Parques Nacionales, project OAPN 352/2011. F. Díaz-Ruiz was supported by a Juan de laCierva postdoctoral contract (Ministerio de Ciencia e Innovación, Funder Id: 10.13039/501100004837, FJCI-2015-24949) from the Spanish Ministry of Economy, Industry and Competitiveness). P. Monterroso was granted a postdoctoral fellowship by the project ‘Genomics Applied to Genetic Resources’ co-financed by North Portugal Regional Operational Program 2007/2013 (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF).

The interactions between animals and their environment vary across species, regions, but also with gender. Sex-specific relations between individuals and the ecosystem may entail different behavioral choices and be expressed through different patterns of habitat use. Regardless, only rarely sex-specific traits are addressed in ecological modeling approaches. The European wildcat (Felis silvestris silvestris) is a species of conservation concern in Europe, with a highly fragmented and declining distribution across most of its range. We assessed sex-specific habitat selection patterns for the European wildcat, at the landscape and home range levels, across its Iberian biogeographic distribution using a multipopulation approach. We developed resource selection functions in a use-availability framework using radio-telemetry data from five wildcat populations. At the landscape level, we observed that, while both genders preferentially established home ranges in areas close to broadleaf forests and far from humanized areas, females selected mid-range elevation areas with some topographic complexity, whereas males used lowland areas. At the home range level, both females and males selected areas dominated by scrublands or broadleaf forests, but habitat features were less important at this level. The strength of association to habitat features was higher for females at both spatial levels, suggesting a tendency to select habitats with higher quality that can grant them enhanced access to shelter and feeding resources. Based on our results, we hypothesize that sex-biased behavioral patterns may contribute to the resilience of wildcats' genetic integrity through influencing the directionality of hybridization with domestic cats. Our study provides information about European wildcats' habitat use in an Iberian context, relevant for the implementation of conservation plans, and highlights the ecological relevance of considering sex-related differences in environmental preferences., This work was supported by a postdoctoral fellowship to PM by FEDER funds through the Operational Programme for Competitiveness Factors—COMPETE and by National Funds through FCT—Foundation for Science and Technology (grant numbers UID/BIA/50027/2013, POCI-01-0145-FEDER-006821); and by a research contract “Juan de la Cierva” to FD-R (grant number FJCI-2015-24949) from the Spanish Ministry of Economy, Industry, and Competitiveness.

[ES]: Actualmente se desconoce la presencia y distribución de los mamíferos en muchos lugares remotos, pese a que suelen ser lugares ricos en biodiversidad. El objetivo de este trabajo fue caracterizar la comunidad de mamíferos terrestres de la Reserva de Huinay, sur de Chile, mediante tres metodologías: i) encuestas a residentes y visitantes de la zona (n=42); ii) transectos de indicios (excrementos, huellas, etc; se recorrieron 80 km en total); y iii) foto-trampeo (se colocaron 18 cámaras-trampa con un esfuerzo total de 590 trampas-día). Se identificaron 13 especies de mamíferos terrestres. El pudú (Pudu puda), la güiña (Leopardus guigna) y el quique (Galictis cuja) fueron las únicas identificadas mediante los tres métodos. Nuestros resultados sugieren que diferentes metodologías pueden ser complementarias para determinar la presencia y distribución de las especies en áreas remotas., [EN]: The presence and distribution of mammals in remote areas are currently poorly known, although these areas are usually rich in biodiversity. The main objective of this study was to characterize the terrestrial mammal community within the reserve of Huinay, southern Chile, using three methodologies: i) questionnaires to residents and visitors to the area (n=42); ii) transects of mammals’ presence (scats, tracks, etc; the total length of transects was 80 km); iii) camera-trapping (18 camera-traps were set with a total sampling effort of 590 trap-days). A total of 13 species of mammals were identified, and only three of them (pudu, Pudu puda, kodkod, Leopardus guigna and lesser grison, Galictis cuja) were recorded with all the methods employed. Our results suggest that different methodologies can complement each other for surveying species presence and distribution in remote areas., Este estudio ha sido financiado por el acuerdo entre la Fundación Endesa, Fundación San Ignacio del Huinay y el CSIC. M. Delibes-Mateos está financiado actualmente por la Consejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía y el 7º programa marco de la Unión Europea para investigación, desarrollo tecnológico y demostración bajo el acuerdo 267226. J. Caro tuvo un contrato postdoctoral financiado por la Junta de Comunidades de Castilla-La Mancha y el FSE en el marco del programa operacional FSE 20072013.

Daily activity patterns in mammals depend on food availability, reproductive stage, habitat selection, intraspecific interactions and predation risk, among other factors. Some mammals exhibit behavioral plasticity in activity patterns, which allows them to adapt to environmental changes. A good example of this can be found in the red fox Vulpes vulpes. This species is adapted to living in highly humanized environments, where it is often culled because it may affect human interests (e.g. through the consumption of game species or livestock). We assessed the potential main drivers of the daily activity patterns of the red fox in 12 Iberian Mediterranean areas through the use of camera traps. Among drivers, we considered main prey availability (European wild rabbits Oryctolagus cuniculus), degree of human disturbance (e.g. distance to human settlements, and intensity of predator control) and habitat structure. Our results revealed a predominantly crepuscular and nocturnal activity of foxes with local variations. Although overall fox activity increased with rabbit availability, the temporal overlap with prey activity was on average low, because foxes increased activity when rabbits decreased theirs (twilight-night). Red fox activity rhythms seemed to be determined by human presence where human disturbance is high. In addition, diurnal activity decreased in areas with higher levels of human disturbance (closer to human settlements and high predator control intensity) and increased in dense habitats. Our study shows that daily activity patterns of highly adaptable species are determined by several interacting drivers, resulting in complex behavioral patterns. This suggests that further ecological studies should consider different factors simultaneously for a better understanding of daily activity patterns of wildlife in different landscapes., This study was funded by projectsCGL2009-10741 (Spanish Ministry of Science and Innovation and EU-FEDER funds); HUNTing for Sustainability(212160, FP7-ENV-2007-1), and OAPN352/2011 (Organismo Autónomo de Parques Nacionales, Spain). F. Díaz-Ruiz and J. Caro enjoyed postdoctoral contracts financedby the European Social Fund (ESF) and the Junta de Comunidades de Castilla-La Mancha (Operational Programme FSE 2007/2013). M. Delibes-Mateos is currently funded by Consejería de Economía, Innovación, Ciencia y Empleo of Junta de Andalucía, and the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement 267226.

How foraging behaviour of predators is influenced by prey abundance is often not clear. Predators may behave as generalist or specialist depending on the relationship between the predator feeding behaviour and prey abundance, known as functional response. The European rabbit (Oryctolagus cuniculus) is a key species for most Iberian vertebrate predators, especially for large raptors such as the eagle owl (Bubo bubo). The eagle owl functional response was analysed in central Iberian Peninsula by fitting different models (null, linear, two asymptotic and two sigmoidal models) between rabbit abundance and rabbit consumption by the eagle owl. Rabbit consumption increased as did its abundance until reaching an asymptote. Rabbit-consumed biomass better fitted to a type II functional response (convex, typical of specialist predators), whereas rabbit frequency in eagle owl diet better fitted to a type III functional response (sigmoidal, typical of generalist predators). Trophic diversity increased as rabbit abundance decreased. The consumption of other prey, such as Iberian hare (Lepus granatensis) and medium-size birds (mainly galliformes and columbiformes), increased as rabbit abundance decreased. The eagle owl is highly dependent on rabbits in central Spain, even at low rabbit abundance. In this situation, the eagle owl diversifies its diet, making it difficult to define the eagle owl as a specialist or as a generalist predator. Therefore, the eagle owl in the centre of the Iberian Peninsula should be rather considered as a facultative predator on wild rabbits., This study is a partial result of CGL2005–02340, CGL2009–10741, and CGL2013-43197 projects, from I+D National Plan funded by the Spanish Ministry of Science and Innovation and EU–FEDER funds. J. Fernandez-de-Simon benefitted from a FPI PhD scholarship (BES–2006–12562) funded by the Spanish Ministry of Science and Innovation and the European Social Fund. J. Fernandez-de-Simon and F. Diaz-Ruiz are currently holding a postdoctoral fellowship from Junta de Castilla-La Mancha and the European Social Fund (Operational Programme FSE 2007/2013).

Biogeographical diversity is central to the trophic ecology of predators. Under- standing the biogeographical trophic patterns of generalist predators, such as the red fox Vulpes vulpes, is particularly challenging because of their wide distribu- tions, broad trophic spectra and high ecological plasticity, which often generate conflicts with humans. 2. We reviewed 55 studies from the Iberian Peninsula concerning the diet of the red fox to describe its trophic patterns from a biogeographical perspective. 3. We considered the frequency of occurrence of seven food groups and charac- terized each study site according to environmental variables. We tested relation- ships between geographical variables and each food group independently, and assessed the consumption of lagomorphs in relation to the other food groups. We also tested the relationships between trophic diversity, the main food groups, lati- tude and altitude, and finally investigated changes in the consumption of all food groups in relation to habitat type and seasonality. 4. We found a latitudinal pattern in the diet of the red fox, which was character- ized by a greater consumption of lagomorphs and invertebrates in southern areas, and a higher intake of small mammals and fruits/seeds in northern regions. Addi- tionally, the consumption of invertebrates increased from east to west, while fruit/ seed consumption increased from west to east. Consumption of lagomorphs decreased, and of small mammals increased, with altitude. Trophic diversity was not associated with geographical variables. The intake of lagomorphs and small mammals was greatest in Mediterranean scrub and forest, respectively. Reptiles and invertebrates were consumed mostly during summer; fruits/seeds in autumn. 5. Iberian red foxes show variation in their feeding habits associated with envi- ronmental variables, which are in turn associated with the availability of their main prey. Foxes select rabbits where they are abundant, and feed on small mammals and fruits/seeds where lagomorphs are scarce. bs_bs_banner

Widespread generalist predators may affect declining keystone prey populations. However, this phenomenon is not well understood. In this paper, we assessed whether the abundance and population growth of European rabbits Oryctolagus cuniculus, a keystone prey species in Mediterranean Iberia, was related to the abundance and diet of red foxes, Vulpes vulpes, a widespread generalist predator. In a locality in central Spain, where rabbit population abundance declined, we estimated rabbit abundance during almost 3 years and determined fox abundance and diet during two concurrent years. We calculated a fox predation index (percentage of consumed rabbit biomass × fox abundance) to assess the importance of rabbits to foxes. We employed a multi–model approach to explain rabbit abundance and population growth. Foxes consumed between 60 and 99 % rabbit biomass in their diets, and this was independent of rabbit abundance. Periods of higher fox predation index coincided with lower rabbit density and vice versa. Two models best explained rabbit abundance and four rabbit population growth. They included the fox predation index and its interaction with rabbit abundance during the previous month. Altogether, fox predation, intraspecific density dependence, and their interaction partly explained rabbit population dynamics. We conclude that in order to propel the recovery of the rabbit in Iberia, it is essential to better understand the role of these factors in driving the abundance of the species., This is a partial result from the I+D National Plan Projects CGL2005-02340, CGL2009-10741 and CGL2013-43197, funded by the Spanish Ministry of Science and Innovation and EU FEDER funds. JFdS benefitted from a FPI PhD scholarship (BES- 2006-12562) funded by the Spanish Ministry of Science and Innovation and the European Social Fund. J. Fernandez-de-Simon and F. Díaz-Ruiz are currently holding a postdoctoral fellowship from Junta de Castilla-La Mancha and the European Social Fund (Operational Programme FSE 2007/2013). M. Delibes-Mateos is currently funded by Junta de Andalucía and the EU FP7, under grant agreement 267226.

[Capsule]: Feeding habits of the Black-billed Magpie are of interest for researchers, conservationists and hunters since magpies are considered as predators of eggs and chicks of both songbirds and gamebirds. [Aims]: To characterize the feeding habits of magpies during their breeding season in agricultural environments of central Spain, and to assess the occurrence and incidence of birds and eggs in the magpie's diet. [Methods]: Diet was determined by the analysis of gizzard contents from 118 culled magpies. The diet was described as the frequency of occurrence (FO) and the percentage of volume (VOL) of a certain food item and for each gizzard. [Results]: Magpies presented a generalist diet, which included a wide range of foods. Arthropods and cereal seeds were the most frequently consumed food groups (FO > 60%). Eggs and birds were consumed only occasionally (FO < 6% and 17%, respectively; percentage of volume, VOL < 4%). [Conclusion]: Our findings suggest that other birds and their eggs do not represent an important food for magpies in Mediterranean agricultural environments under the conditions found during this study. Nevertheless, more complex studies in different scenarios (i.e. different population sizes of magpies and prey), and over longer temporal scales, are still necessary to clarify this controversial issue., The study was funded by Consejería de Medio Ambiente of Junta de Comunidades de Castilla-La Mancha (Project PREG-05-23). F. Díaz-Ruiz holds a postdoctoral contract financed by the European Social Fund (ESF) and the Junta de Comunidades de Castilla-La Mancha (Operational Programme FSE 2007/2013). M. Delibes-Mateos is supported by the Talentia Postdoc Program launched by the Andalusian Knowledge Agency, co-funded by the European Union’s Seventh Framework Program, Marie Skłodowska-Curie actions (COFUND – Grant Agreement n° 267226) and the Ministry of Economy, Innovation, Science and Employment of the Junta de Andalucía.