Rabbit Abundance Research Articles

A test of whether rabbit abundance increases following predator control in a rural landscape

A test of whether rabbit abundance increases following predator control in a rural landscape

Spatiotemporal analysis of landscape dynamics and their use as input for the design of a habitat suitability index: A case study of Oryctolagus cuniculus in a Mediterranean region

The connectivity of landscapes is increasingly threatened by urban sprawl, which leads to the fragmentation of habitats and thus endangers the species that live there. To address this situation, landscape dynamics in the literature have mostly been analyzed using predefined land cover classes, which were then not used to assess habitat suitability, but instead relied on physical variables. As a bridge between both aspects, this study aimed to model the spatiotemporal patterns of landscape fragmentation by analyzing the landscape metrics associated with four land cover groups classified according to their naturalness. Landscape metrics were then combined with a range of terrain, climate and proximity variables to develop a Habitat Suitability Index (HSI) for terrestrial animal species. The proposed methodology was tested using a case study in the Mediterranean region of the Valencian Community (Spain): landscape dynamics were assessed over the period 1992–2015, while the HSI was tested with the European rabbit (Oryctolagus cuniculus) as the target species. The results obtained in terms of landscape dynamics showed a growing presence of artificial surfaces at the expense of fewer transformed areas, which became progressively fragmented over time. Moreover, the results of the developed HSI were highly concordant with observations of rabbit abundance in the region, based in particular on variables related to the temperature in the area and the patch shape in the preferred habitats of this species. These outputs can be used to support the implementation of habitat restoration strategies aimed at increasing ecological connectivity through measures such as wildlife crossings.

Is the Iberian lynx a hunters’ ally? a case study from a reintroduced population in Portugal

The Iberian lynx (Lynx pardinus) is one of the most endangered felids in the world, and a high proportion of its populations occur in hunting grounds managed for red-legged partridge (Alectoris rufa) and wild rabbit (Oryctolagus cuniculus), both game species of high socio-economic value and the latter a key prey species for the lynx. In this case study from south-eastern Portugal, we evaluated the game management practices, the abundance of partridges and rabbits (expressed as Kilometric Abundance Index), and the occurrence of mesocarnivores in four hunting grounds, two with and two without breeding lynx. In all grounds game management was conducted but in those where lynx occurred, full-time gamekeepers were employed and hunting was the major source of income. The results showed that grounds with breeding lynx had higher KAI values for partridges and rabbits, together with reduced mesocarnivores occurrence (particularly red fox Vulpes vulpes and stone marten Martes foina), compared to those without breeding lynx. Our results confirm that lynx occurrence fits within the management traits of those hunting grounds in Iberia aiming to increase partridges and rabbits for sustainable hunting, as they act as ‘natural’ gamekeepers. This could be considered as a ‘win-win’ situation; successful for lynx’s establishment and small game conservation.

Variable importance and scale of influence across individual scottish wildcat hybrid habitat models

Understanding the scale dependence of species-habitat relationships is an important area of research in species distribution modeling. There has been little research focused on how habitat selection may depend on individual variation among organisms, geographical location and ecological context of that location. Furthermore, little is known about the extent and drivers of heterogeneity of scale dependence among individuals of a species inhabiting different ecological contexts, and few studies have compared scale dependence and variable importance in a spatially replicated framework. Two of the most important factors for interpreting habitat relationships models include: (1) the relative importance of variables in the model and (2) the spatial scale at which each variable has the largest influence. Based on the existing evidence we hypothesize a priori that landcover variables will generally be the most important predictors, followed by topography, then soil type (which influence both vegetation and prey), Normalized Difference Vegetation Index (NDVI) as an indicator of total vegetation density and perhaps a proxy for prey density, vegetation cover and rabbit abundance. We also expected a priori that there would be consistent patterns of scale dependence across individual wildcat hybrid models related to different variable groups. We expected topographical features to be selected at broad scales, as they influence broad-scale climatic and ecological conditions. We also expected that land cover classes and vegetation cover density to be selected at relatively broad scales given past research showing land cover generally influences habitat selection at relatively broad scales. We expected NDVI and soil type to be selected at finer scales, as their variation influences the distribution of resources and limiting conditions within landscapes. Finally, we expected that rabbit abundance and linear features would affect wildcat hybrid occurrence at the finest scales, given these are resources and conditions that vary over short distances and strongly influence wildcat and wildcat hybrid behavior and habitat use. Our results were consistent with the hypothesis that there may be consistency regarding which variables or variable groups are most important as predictors of wildcat hybrid occurrence in Scotland. Based on previous research we expected that there would be consistent patterns of scale dependence across individual wildcat hybrid models related to different variable groups. Finally, our results identify a clear and consistent trend of increasing frequency of inclusion of variables at increasingly broad scales. This is a linear trend in frequency of variables retained increasing as the scale increased. This suggests a consistent and monotonic pattern of more frequent retention of variables at increasingly broad scales.

Direct and indirect landscape-scale pathways structure carnivore communities in an agro-prairie ecosystem

Abstract Many carnivore populations have experienced substantial declines and are at increased risk of extinction, mainly due to negative interactions with humans and biological traits that make them susceptible to habitat loss and fragmentation, often driven by agricultural expansion. Carnivore community richness is likely influenced by many direct and indirect factors, though it is unclear how carnivore communities are structured in prairie landscapes that are considered one of the most imperiled ecosystems worldwide. Our goal was to identify landscape-scale effects driving carnivore community richness in a contemporary agro-prairie ecosystem. We used 3 years of presence data (2018–2020) from camera-trap sites (n = 381) distributed across western Kansas, United States and developed a structural equation model (SEM) to test a priori hypotheses explaining carnivore richness. Measures of water availability, native prairie, and agriculture—as well as sampling effort (i.e., days cameras were active)—were all positively associated with carnivore richness. Additionally, our index of rabbit abundances at sites had a direct positive effect on our measure of carnivore richness. Our SEM explained 42% of the variance in carnivore richness (χ2 = 8.76, d.f. = 21, P = 0.99) in this human-dominated landscape. Our results suggest that carnivore communities in agro-prairie landscapes are structured through multiple direct and indirect landscape-scale pathways. Contemporary agro-prairie mosaics may act as filters for the agricultural tolerance of carnivores, with species more vulnerable to native prairie loss becoming locally extirpated.

High Mortality of Wild European Rabbits during a Natural Outbreak of Rabbit Haemorrhagic Disease GI.2 Revealed by a Capture-Mark-Recapture Study

Rabbit haemorrhagic disease virus (RHDV) GI.2 has caused significant declines in the abundance of wild European rabbits (Oryctolagus cuniculus), contributing to the species being recently classified as “endangered” in its native range. The epidemiology of this virus is still poorly understood despite its relevance for domestic and wild rabbits. During a longitudinal capture-mark-recapture (CMR) study of wild Iberian rabbits, O. c. algirus, in a semiextensive breeding enclosure, an outbreak of RHDV GI.2 took place in January-February 2022, allowing us to estimate key epidemiological parameters of a natural outbreak. From April 2021 to July 2022, 340 rabbits were captured 466 times and individually identified, and some were vaccinated against myxoma virus (MYXV) and/or RHDV GI.2. Sera were collected and tested for IgG specific for MYXV and RHDV GI.2, and data were analyzed using multievent CMR models. During six weeks in January-February 2022, an estimated 81.0% (CI95 77.1–84.3%) of the population died. Intensive aboveground searches could recover 189 carcasses (50.5% of the estimated mortality, CI95 41.8–63.4%), with RHDV GI.2 detected in 6/7 tested. Apparent RHDV GI.2 seroprevalence rose from 15.4% (CI95 8.0–27.5%) in January 2022 to 87.9% (CI95 72.7–95.2%) in February 2022. The apparent mortality of RHDV GI.2-seropositive rabbits during the outbreak was estimated as null, while for seronegative rabbits, it was 76.0% (CI95 53.8–90.3%). Among the seronegative rabbits, mortality was higher in unvaccinated (100%) than in recently vaccinated (60.0 ± 16.6%) and in females (100%) than in males (52.0 ± 17.1%). Infected carcasses in the burrows might explain the medium-term disease persistence in the population following the outbreak. Rabbits with antibodies at the cutoff for seropositivity were fully protected from fatal infection. Females had a higher fatality rate than males, underscoring the impact of RHDV GI.2 on the population dynamics of this endangered species.

Seasonal and spatial variations in the diet of the Egyptian mongoose in its north-eastern Iberian range edge

The Egyptian mongoose (Herpestes ichneumon) is considered a generalist and opportunistic predator whose European distribution is restricted to Iberia. However, all the previous studies on the Egyptian mongoose’s diet in the Iberian Peninsula have been performed in Portugal and Doñana National Park (southwestern Spain), covering a small region of the species’ current distribution. To improve the knowledge on the trophic ecology of the species, we estimated the feeding habits of the Egyptian mongoose in central Spain, its north-eastern range edge. Our study was based on the analysis of (1) scats (n = 251) and (2) stomach contents (n = 32); samples were collected between 2018 and 2022. We calculated the relative frequency of occurrence (%RFO) and the percentage consumed biomass (%CB) for 12 food groups across central Spain and we assessed site-seasonal variations in diet composition in three study areas. We also estimated rabbit densities in the three study areas to assess the effect of rabbit abundance on mongoose diets. Overall, our results showed that European rabbits were the group with highest %CB (30.7%) in the diet of the Egyptian mongoose, followed by reptiles (19.9%) and small mammals (19.9%). In the intensively studied areas, the %CB of rabbits was the highest in the area with the highest abundance of this prey, whereas reptiles had the highest %CB in the area with the lowest availability of rabbits. Diet diversity (Shannon index) varied between 1.73 and 2.47 in those areas and was inversely related to the availability of rabbits. Our results confirm the dietary flexibility of this predator that adapts its diet to the relative availability of different prey species in different habitats.

Sustained Impact of RHDV2 on Wild Rabbit Populations across Australia Eight Years after Its Initial Detection.

Following the arrival of rabbit haemorrhagic disease virus 2 (RHDV2) in Australia, average rabbit population abundances were reduced by 60% between 2014 and 2018 based on monitoring data acquired from 18 sites across Australia. During this period, as the seropositivity to RHDV2 increased, concurrent decreases were observed in the seroprevalence of both the previously circulating RHDV1 and RCVA, a benign endemic rabbit calicivirus. However, the detection of substantial RHDV1 seropositivity in juvenile rabbits suggested that infections were continuing to occur, ruling out the rapid extinction of this variant. Here we investigate whether the co-circulation of two pathogenic RHDV variants was sustained after 2018 and whether the initially observed impact on rabbit abundance was still maintained. We monitored rabbit abundance and seropositivity to RHDV2, RHDV1 and RCVA at six of the initial eighteen sites until the summer of 2022. We observed sustained suppression of rabbit abundance at five of the six sites, with the average population reduction across all six sites being 64%. Across all sites, average RHDV2 seroprevalence remained high, reaching 60-70% in adult rabbits and 30-40% in juvenile rabbits. In contrast, average RHDV1 seroprevalence declined to <3% in adult rabbits and 5-6% in juvenile rabbits. Although seropositivity continued to be detected in a low number of juvenile rabbits, it is unlikely that RHDV1 strains now play a major role in the regulation of rabbit abundance. In contrast, RCVA seropositivity appears to be reaching an equilibrium with that of RHDV2, with RCVA seroprevalence in the preceding quarter having a strong negative effect on RHDV2 seroprevalence and vice versa, suggesting ongoing co-circulation of these variants. These findings highlight the complex interactions between different calicivirus variants in free-living rabbit populations and demonstrate the changes in interactions over the course of the RHDV2 epizootic as it has moved towards endemicity. While it is encouraging from an Australian perspective to see sustained suppression of rabbit populations in the eight years following the arrival of RHDV2, it is likely that rabbit populations will eventually recover, as has been observed with previous rabbit pathogens.

Cooke’s index: A simple, cost-effective method for multiple practitioners to estimate European rabbit abundance

The development of evidence-based tools that help to monitor wildlife populations is essential to assess the success of management interventions. Here, we evaluated the reliability of a simple method to estimate the abundance of the European rabbit (Oryctolagus cuniculus), which is likely one of the most managed vertebrate species worldwide. Cooke’s method involves noting the distribution and frequency of sightings of rabbit fecal pellets and accordingly scoring the abundance of rabbits on a scale 0–5. To assess its reliability, we used information collected during 101 rabbit surveys conducted across mainland Spain during the summer of 2022. In each 4-km walked transect, we estimated rabbit abundance using Cooke’s method every 400 m (i.e., 10 indexes), and pellet counts (2 plots per 100 m walked, i.e., 80 counts), which were used as a reference index. Our results revealed a strong correlation between the estimates of rabbit abundance obtained using Cooke’s method and the number of pellets counted per m2 regardless of the statistical approach used. This suggests that Cooke’s method provides a simple and inexpensive way of estimating the abundance of European rabbits, which we believe that can be very useful for non-expert land managers after a very short training period. Importantly, our findings demonstrate that it is reliable to estimate rabbit abundance in different land uses. In addition, Cooke’s method can be used in different seasons, is not affected by circadian activity of rabbits, seems to work well across the whole range of rabbit abundance, and may be useful for estimating rabbit abundance at different spatial scales. As everyday people rather than scientists are generally involved in managing European rabbits, we strongly recommend this simple method that allows rabbit abundance to be quickly estimated so that management decisions can be made. More broadly, we encourage researchers to investigate the usefulness of similar monitoring tools for other mammal species that are often surveyed through counting their pellets.

Forest raptor nest selection traits in Mediterranean forest (Maamora, North Africa): conservation implications

SummaryForest raptor nest-site selection is mostly influenced by the quality of the habitat, food resources, and competition. Here, we identified common targets of trees selected as breeding sites and differences in selection traits, i.e. prey availability and intra- and interspecific competition, among Booted Eagle, Long-legged Buzzard, Black Kite, and Common Kestrel in a Mediterranean Cork Oak forest (private protected reserve of 25 km2). Using generalised linear mixed models we developed species-specific models describing nesting habitat selection. We tested the overlap in nesting habitat selection among species using environmental principal component analysis. The densities of forest raptor breeding pairs were high (3.1 pairs/km2) and the distance between occupied territories was short, strongly connected with food availability and competition. The results showed that all the species, with the exception of Common Kestrel, selected for nesting areas characterised by higher conspecific distance, highlighting the importance of conspecific competition. Booted Eagle and Black Kite selected areas with a high abundance of rabbits. The height of the nesting tree, the size and distance between surrounding trees, and the scrub cover were significant habitat characteristics for Booted Eagle and Long-legged Buzzard. Indeed, the environmental analyses showed a moderate nest site overlap between Black Kite and both Booted Eagle and Long-legged Buzzard, and a high overlap between Common Kestrel and both Booted Eagle and Long-legged Buzzard. Our study improves knowledge of the habitat requirements for nest selection and the potential competitive interactions between these raptor species in Mediterranean forests, and highlights the need for implementation of habitat management and conservation strategies.

Spatiotemporal predictions of the alternative prey hypothesis: Predator habitat use during decreasing prey abundance

AbstractThe alternative prey hypothesis supposes that predators supported by a primary prey species will shift to consume alternative prey during a decrease in primary prey abundance. The hypothesis implies that during declines of one prey species, a predator modifies their behavior to exploit a secondary, or alternative, species. Despite occurring in many systems, the behavioral mechanisms (e.g., habitat selection) allowing predators to shift toward alternative prey during declines in the abundance of their primary prey are poorly understood. We evaluated habitat selection and use by a generalist predator with respect to two prey species during a dramatic decrease in the abundance of primary prey. Further, we evaluated how spatial variation in access to primary prey affected habitat selection, and assessed similarity and overlap between habitats used by each prey species. Coyotes (Canis latrans) exhibited decreasing selection for cottontail rabbits (Sylvilagus spp.; primary prey) during population decreases but did not shift habitat selection toward neonate mule deer (Odocoileus hemionus; alternative prey). Use of rabbit habitat remained high even during historically low rabbit abundance, while mule deer habitat was used in proportion to its availability. Coyotes seemingly do not make large shifts in habitat selection toward alternative prey following spatial and temporal decreases in the abundance of primary prey, but instead, take advantage of habitat overlap to facilitate prey‐switching behavior. Our work extends previous research conducted under the alternative prey hypothesis by explicitly evaluating the influence of habitat overlap between prey species and variation in access to prey habitat as factors affecting prey‐switching behaviors in predators.

Iberian lynxes scavenging on ungulate carcasses: An overlooked important resource and potential risk for an endangered predator

Carrion is a valuable food source for predators, but its role for specialist predators has received little attention. We recorded the unnoticed scavenging behavior of the endangered Iberian lynx (Lynx pardinus) on wild ungulate carcasses in a reintroduced lynx population of central Spain. Seven of the 13 carcasses experimentally placed (54 %) were visited and scavenged by Iberian lynxes. Five carcasses (38 %) were scavenged by more than one lynx (one to seven individuals) and sometimes by several individuals at the same time (two adults and one young). Large proportion of the lynxes in the study area (12 of 17; 71 %) ate carrion. Our observations are surprising and suggest that this behavior is probably more common in this species than previously assumed. In addition, this behavior has implications for the conservation of this threatened species, since it confirms the potential risks associated with the consumption of carrion from animals killed by disease, or by human activities such as livestock rearing or hunting. The potential conservation problems that may arise from carrion consumption by lynxes, such as exposure to disease-causing pathogens, toxins, poisoning due to the lead ammunition or even intentional poisoning, should be evaluated in-depth. Likewise, the use of ungulate carrion could be an important resource for lynxes in areas with low rabbit abundance, and probably as a management tool in conservation programs.

First insular population of the critically endangered Cistus heterophyllus subsp. carthaginensis on Cabrera Archipelago National Park (Balearic Islands, Spain)

Cistus heterophyllus subsp. carthaginensis is considered one of the most endangered plants of Spain and has been object to many conservation programs and research projects. Until now, only two small spots were located in Europe: a population of one self-incompatible specimen was found in Valencia and another small population in Cartagena, disturbed by human impact and hybridization with close-relatives. Therefore, the conservation of this taxon has been one of the most defeating issues in the current plant conservation strategies of the Mediterranean workgroups. In this study, we report, describe and cense a new population of this taxon located at the furthest accessible area of the isle of Cabrera Gran in Cabrera Archipelago National Park. The population contains 59 individuals of C. heterophyllus subsp. carthaginensis, the most abundant known population of this species, with a high representation of young individuals (83%). However, some threats are currently compromising the stability of this population: the presence of Cistus albidus in surrounding areas is producing hybrids (Cistus × clausonii) and the high abundance of rats and rabbits is affecting the population recruitment. For this reason, urgent conservation actions must be designed to protect and enhance this population. Overall, this new finding offers new insights on the distribution and conservation strategies of this species.

Predation impact on threatened spur-thighed tortoises by golden eagles when main prey is scarce

A reduction in adult survival in long-living species may compromise population growth rates. The spur-thighed tortoise (Testudo graeca) is a long-lived reptile that is threatened by habitat loss and fragmentation. Golden eagles (Aquila chrysaetos), whose breeding habitats overlap that of tortoises, may predate them by dropping them onto rocks and breaking their carapaces. In SE Spain, the number of golden eagles has increased in the last decades and the abundance of their main prey (i.e., rabbits Oryctolagus cuniculus) has decreased. Our aims were to 1) describe the role of tortoises in golden eagles’ diet, and 2) estimate the predation impact of golden eagles on tortoises in eagles’ territories and in the regional tortoise population. We collected regurgitated pellets and prey remains under eagle nests and roosts, and obtained information on tortoise abundance and population structure and rabbit abundance. We found that tortoises were an alternative prey to rabbits, so that eagles shifted to the former where the latter were scarce. The average predation rate on tortoises was very low at the two studied scales. However, eagles showed a marked selection for adult female tortoises, which led the tortoise sex ratio to be biased towards males in those eagle territories with higher tortoise predation. Whether this may compromise the spur-thighed tortoise long-term population viability locally deserves further attention.

Long-term response of open-habitats species to wildfire salvage logging: the endangered European wild rabbit as example

Salvage logging treatments, a type of logging to economic returns after natural disturbance, are often applied in the aftermath of wildfires. Specialist or dependent species of open-habitat usually increase their populations in the short-term after wildfires and post-fire salvage logging. However, the long-term effects on threatened open-habitat species such as the European wild rabbit (Oryctolagus cuniculus L.) are still poorly known. Thus, plant productivity, habitat heterogeneity and rabbit abundance were studied in the north-east Iberian Peninsula in four type of post-fire treatment plots: (1) unburnt, (2) salvage logging with branches left on the ground, (3) salvage logging and manual removal of branches, and (4) recurrent fires. Both the time since the fire and the treatment affected plant productivity and habitat heterogeneity. Plant productivity was quicker in treatments when branches were left on the ground or when branches were removed than in recurrent fire plots. Rabbit relative abundance increased in the short term but dramatically declined over time after fires, especially in the plots where branches were left on the ground and with recurrent fires, in which rabbit abundances fell dramatically. In the long-term, the lack of food availability and adequate habitat structure are the main factors affecting the maintenance of the rabbit population. An appropriate moment for managing burnt areas to favour the persistence of rabbit is between the fifth and sixth year after the fire. These actions also benefit the reduction of environmental biomass and so help prevent future severe wildfires.

Fifty-year review: European rabbit fleas,

European rabbit fleas were released among Australian wild rabbits in the late 1960s to supplement mosquitoes as vectors of myxoma virus. Data from study sites across southern Australia in the 1960s and 1970s are reviewed to discern common elements of flea-borne myxomatosis epizootics and a simple model is proposed to explain how virus virulence and food quality interact to determine rabbit abundance. Low, stable populations of rabbits implied that, despite virus attenuation and increased rabbit disease resistance, flea-borne myxomatosis was extremely important in controlling rabbit populations. Despite the enhancement of myxomatosis, livestock producers benefitted little from the additional pasture because marketing difficulties were not conducive to industry growth. Native wildlife likely benefitted, nonetheless.

Recovering Australia's arid‐zone ecosystems: learning from continental‐scale rabbit control experiments

Introduced rabbits are a continuing threat to native Australian flora and fauna. Three interventions using biological control agents, myxomatosis, European rabbit fleas, and rabbit hemorrhagic disease, have reduced rabbit abundance and kept numbers low over the last 70 years. We considered the benefits of biological control for native fauna to put the role of rabbits in influencing vegetation cover, food supply, and predation into better perspective. Numerous examples exist demonstrating increases in native vegetation and the expansion and recovery of native animal populations at landscape scales following intense rabbit suppression. Ongoing research on methods for supplementing the impact of biological control agents and managing introduced predators are needed to restore Australia's arid‐zone ecosystems. However, many biologists and rangeland managers first need to reevaluate the misconception that removing rabbits also introduces other serious and insurmountable problems such as prey‐switching by introduced cats and foxes.

The ecological costs and benefits of a feral cat poison‐baiting programme for protection of reintroduced populations of the western quoll and brushtail possum

AbstractConservation practitioners implement management interventions for the protection of threatened species, but the benefits are rarely measured. We investigated the efficacy of aerial poison baiting for feral cats, a species identified as a threat to reintroduced populations of two Australian mammals. We measured individual survival, short‐term changes in activity and longer term population trajectories in cats and reintroduced western quolls and brushtail possums before and after annual baiting events. Between 87% and 100% of radiocollared feral cats that remained in the baited area died from poisoning in 2017, 2018 and 2019. Camera detection rates significantly declined after each event (40–77%), and the proportion of cameras occupied remained lower after baiting commenced (20–60% before vs. &lt;20% after). Cat decline on cameras was significantly higher in areas with low rabbit abundance, suggesting controlling alternative prey would improve baiting success. Importantly, none of 37 radiocollared quolls died from poisoning despite pre‐baiting trials determining that they were the most common species removing baits (26%). We detected no negative impact of baiting on the quoll and possum populations but could not demonstrate a significant net benefit. Trapping data suggested no change in annual quoll survival after baiting despite a slight increase in survival of radiocollared quolls. Quoll detection rates on camera did not significantly decline after each baiting event. A decline in the last two years of monitoring was possibly due to drought conditions. Approximately 10% of radiocollared possums died from poisoning after the first baiting event, but trapping and camera detections suggested a stable or increasing population. Poison baiting successfully reduced cat abundance, and there was no measurable negative effect on populations of reintroduced species. Long‐term monitoring through a range of seasonal conditions is required to determine the net benefit of predator control for reintroduced populations where paired impact and control sites are impractical.

Exploratory and territorial behavior in a reintroduced population of Iberian lynx

In reintroduction projects, an analysis of dispersal, exploratory movements and territorial behavior of the species concerned offers valuable information on the adaptive management of threatened species and provides a basis for the management of future reintroductions. This is the case of the Iberian lynx (Lynx pardinus) an endemic and endangered species reintroduced in Extremadura (Spain) in 2014. We analysed spatial data from 32 individuals just after their reintroduction. Our findings show exploratory movements sufficient to colonise and connect population nuclei within a radius of about 50 km of the reintroduction area. No significant differences were found in the exploratory movements capacity or in any directionality of males and females. Our results showed an effect of sex on the sizes of the territories established, as well as an inverse relationship between them and the time elapsed since release. No effects of rabbit abundance and lynx density on the size of territories are occurring during the early stages of reintroduction. On average, the territories of reintroduced individuals were less stable than those previously described in natural populations. Findings indicate that the reintroduced population has successfully been established but it takes more than 5 years to stabilize the territories in the area. Exploratory movements of reintroduced lynx can be large and in any direction, even when there is still a lot of high quality habitat available, which should be taken into account when reintroducing species, especially terrestrial carnivores.

Wildcat population density in NE Portugal: A regional stronghold for a nationally threatened felid

AbstractPopulation density data on depleted and endangered wildlife species are essential to assure their effective management and, ultimately, conservation. The European wildcat is an elusive and threatened species inhabiting the Iberian Peninsula, with fragmented populations and living in low densities. We fitted spatial capture–recapture models on camera‐trap data, to provide the first estimate of wildcat density for Portugal and assess the most influential drivers determining it. The study was implemented in Montesinho Natural Park (NE Portugal), where we identified nine individuals, over a total effort of 3,477 trap‐nights. The mean density estimate was 0.032 ± 0.012 wildcat/km2, and density tended to increase with distance to humanized areas, often linked to lower human disturbance and domestic cat presence, with forest and herbaceous vegetation cover and with European rabbit abundance. Although, this density estimate is within the range of values estimated for protected areas elsewhere in the Iberian Peninsula, our estimates are low at the European level. When put in context, our results highlight that European wildcats may be living in low population densities across the Iberian Mediterranean biogeographic region. No phenotypic domestic or hybrid cats were detected, suggesting potentially low admixture rates between the two species, although genetic sampling would be required to corroborate this assertion. We provide evidence that Montesinho Natural Park may be a suitable area to host a healthy wildcat population, and thus be an important protected area in this species' conservation context.