Targeted and untargeted metabolomic profiles in wild rabbit does (Oryctolagus cuniculus) of different breeding states (pregnant and lactating).

Ecological nutrition aims to unravel the extensive web of nutritional links that drives animals in their interactions with their ecological environments. Nutrition plays a key role in the success of European wild rabbit (Oryctolagus cuniculus) and could be affected by the breeding status of the animals and reflected in the metabolome of this species. As nutritional needs are considerably increased during pregnancy and lactation, the main objective of this work was to determine how the breeding status (pregnant and lactating) of European wild rabbit does affects nutritional requirements and their metabolome (using targeted and untargeted metabolomics), aiming to find a useful biomarker of breeding status and for monitoring nutritional requirements. To address this gap, 60 wild European rabbits were studied. Animals were divided according to their breeding status and only pregnant (n = 18) and lactating (n = 11) rabbit does were used (n = 29 in total). The body weight and length of each animal were analyzed. The relative and absolute chemical composition of the gastric content and whole blood sample were taken, and targeted and untargeted metabolomics were analyzed. As a main result, there were no differences in biometric measurements, gastric content, and targeted metabolomics, except for live weight and nonesterified fatty acids (NEFA), as pregnant animals showed higher live weight (+12%; p = 0.0234) and lower NEFA acid levels (-46%; p = 0.0262) than lactating females. Regarding untargeted metabolomics, a good differentiation of the metabolome of the two breeding groups was confirmed, and it was proven that pregnant animals showed higher plasmatic levels of succinic anhydride (3.48 more times; p = 0.0236), succinic acid (succinate) (3.1 more times; p = 0.0068) and propionic acid (3.98 more times; p = 0.0121) than lactating animals. However, lactating animals showed higher levels of N-[(3a,5b,7b)-7-hydroxy-24-oxo-3-(sulfoxide) cholan-24-yl]-Glycine (cholestadien) (2.4 more times; p < 0.0420), 4-maleyl-acetoacetate (MAA) (3.2 more times; p < 0.0364) and irilone (2.2 more times; p = 0.0451) than pregnant animals, any of these metabolites could be used as a potential biomarker. From these results, it can be concluded that the most notable changes were observed in the metabolome of individuals, with most of the changes observed being due to energy and protein mobilisation.

Exposure to Coxiella burnetii in Wild Lagomorphs in Spanish Mediterranean Ecosystems.

Coxiella burnetii is an important zoonotic pathogen of worldwide distribution that can infect a wide range of wild and domestic species. The European wild rabbit (Oryctolagus cuniculus) can play a role as a reservoir for this bacterium in certain epidemiological scenarios, but, to date, a very limited numbers of large-scale serosurveys have been conducted for this species worldwide. Although exposure in hare species has also been described, C. burnetii in Iberian hare (Lepus granatensis) has never been assessed. Here, we aimed to determine the seroprevalence and risk factors associated with C. burnetii exposure in wild lagomorphs in the Mediterranean ecosystems of southern Spain. Between the 2018/2019 and 2021/2022 hunting seasons, blood samples from 638 wild lagomorphs, including 471 wild rabbits and 167 Iberian hares, were collected from 112 hunting grounds distributed across all eight provinces of Andalusia (southern Spain). The overall apparent individual seroprevalence was 8.9% (57/638; 95% CI: 6.8-11.4). Antibodies against C. burnetii were found in 11.3% (53/471; 95% CI: 8.4-14.1) of the wild rabbits and 2.4% (4/167; 95% CI: 0.1-4.7) of the Iberian hares. Seropositive animals were detected for 16 (14.3%; 95% CI: 7.8-20.8) of the 112 hunting grounds tested and in all the hunting seasons sampled. A generalized estimating equations model showed that the geographical area (western Andalusia) and presence of sheep were risk factors potentially associated with C. burnetii exposure in wild lagomorphs. A statistically significant spatial cluster (p < 0.001) was identified in the south-west of Andalusia. Our results provide evidence of moderate, endemic and heterogeneous circulation of C. burnetii in wild lagomorph populations in Spanish Mediterranean ecosystems. Risk-based strategies for integrative surveillance programs should be implemented in these species to reduce the risk of transmission of the bacterium to sympatric species, including humans.

A new HaCV-EBHSV recombinant lagovirus circulating in European brown hares (Lepus europaeus) from Catalonia, Spain.

In 2020/2021, several European brown hare syndrome virus (EBHSV) outbreaks were recorded in European hares (Lepus europaeus) from Catalonia, Spain. Recombination analysis combined with phylogenetic reconstruction and estimation of genetic distances of the complete coding sequences revealed that 5 strains were recombinants. The recombination breakpoint is located within the non-structural protein 2C-like RNA helicase (nucleotide position ~ 1889). For the genomic fragment upstream of the breakpoint, a non-pathogenic EBHSV-related strain (hare calicivirus, HaCV; GII.2) was the most closely related sequence; for the rest of the genome, the most similar strains were the European brown hare syndrome virus (EBHSV) strains recovered from the same 2020/2021 outbreaks, suggesting a recent origin. While the functional impact of the atypical recombination breakpoint remains undetermined, the novel recombinant strain was detected in different European brown hare populations from Catalonia, located 20-100 km apart, and seems to have caused a fatal disease both in juvenile and adult animals, confirming its viability and ability to spread and establish infection. This is the first report of a recombination event involving HaCV and EBHSV and, despite the recombination with a non-pathogenic strain, it appears to be associated with mortality in European brown hares, which warrants close monitoring.

Nutritional ecology of European rabbit (Oryctolagus cuniculus): Factors affecting chemical composition of gastric content.

Nutritional ecology seeks to unravel the extensive web of nutritional links that directs animals in their interactions with their ecological and social environments. European rabbit (Oryctolagus cuniculus) populations its endemic locations are declining and it is considered a keystone species of the Mediterranean ecosystem prompteing the interest in its conservation. The main aim of this study was to determine the nutritional composition of the diet of European rabbits through the relative and absolute chemical composition of the gastric content. To address this objective, gastric content was collected from 80 European rabbits in a Mediterranean area for the analysis of its chemical composition. To this end, gastric content was analyzed for dry matter (DM), organic matter (OM), ash, crude protein (CP), highly digestible nonnitrogenous nutrients (HDNN), neutral detergent fibre (NDF), acid detergent fibre (ADF) and lignin. The rabbits were divided into two groups: EMPTY and FULL, depending on the level of stomach filling, directly related to food intake. Our results revealed a positive correlation between the rabbits weight with DM in the gastric content, total gastric content with DM in the gastric content, and DM in gastric content with all chemical parameters analysed. The mean relative values obtained were 8.8%, 25.5%, 40.4% and 25.4%, for ash, CP, NDF and HDNN, respectively. Moreover, EMPTY rabbits had both a proportional (+19%, p = 0.002 and -40%; p = 0.004, on NDF and HDNN, respectively) and absolute (-38%, p = 0.014, -52%; p = 0.012, -52%; p = 0.011 and +83%; p = 0.008 for OM, ash, HDNN, and lignin, respectively) different proportion of nutrients in gastric contents than FULL animals. Since there is a connection between this availability and the fitness of this species, understanding the chemical composition of the rabbit's diet can be utilised to delve into its biology. Our study provides information that will help elucidate the factors affecting the chemical composition of the gastric content of European rabbits to assist land use planners and conservationists in identifying sites for conservation in Mediterranean ecosystems.

The nutritional strategy of European rabbits is affected by age and sex: Females eat more and have better nutrient optimisation.

The ecological interest in the European rabbit (Oryctolagus cuniculus) has grown since it was declared an endangered species. Nutrition is fundamental in its dispersion and the key to its success. This is the main reason why knowledge of their nutritional preferences/requirements could play a fundamental role in rabbit biology and, therefore, in their conservation. The objectives of the work will be to elucidate how age and sex affect both nutritional preferences/requirements, and the nutrient optimisation of European rabbits. To address this gap, 70 wild European rabbits were studied. The rabbits were divided according to their age: adult (n = 43) and young (n = 27). Two groups were differentiated according to the adult rabbits' sex: females (n = 28) and males (n = 15). We analysed the relative (%) and absolute (g) chemical composition of the rabbits' gastric contents: dry matter (DM), ashes (ASH), crude protein (CP), ether extract (EE), neutral detergent fibre (NDF), acid detergent fibre (ADF), and lignin, hemicelluloses and celluloses, highly digestible nonnitrogenous nutrients (HDNN: fat, starch, and soluble fibre), well from the blood was analysed with plasmatic urea nitrogen (PUN), nonesterified fatty acid (NEFA) and glucose (GLU). As a nutrient optimisation measure, the following indices between blood metabolites and stomach content were calculated: PUN/CP total content, NEFA/DM total content and GLU/DM total content ratios. Our works showed that age and sex affected the nutritional strategy of rabbits. Regarding age: adults showed lower CP (-14%; p = 0.0217) and higher HDNN (+21%; p = 0.0399) relative content than young rabbits, and absolute amount of most nutrients: DM (+59%; p = 0.001), OM (+43%; p = 0.0049), ASH (+54%; p = 0.0085), Hemicelluloses (+73%; p = 0.0084), Cellulose (+27%; p = 0.0452), and HDNN (+63%; p = 0.0012). In addition, adults showed better nutrient optimisation. Sex did not affect the relative chemical composition of the gastric content, but it showed a clear higher gastric content by females (+85%; p < 0.0001) and higher intake of most of the absolute chemical components: DM (+64%; p < 0.001), CP (+56%; p = 0.0005), OM (+58%; p = 0.0001), ASH (+44%; p = 0.0123), HDNN (+39%; p = 0.001), NDF (+59%; p = 0.001), ADF (+64%; p = 0.0003), lignin (+82%; p = 0.0036) and cellulose (+58%; p = 0.0002). Finally, we observed that females had better nutrient optimisation than males. This works supports the idea that feeding ecology and nutrition are particularly relevant to reproductive success and fitness in wild animals.

Comparison of the Impact between Classical and Novel Strains of Rabbit Haemorrhagic Disease on Wild Rabbit Populations in Spain.

The outbreaks of two strains of rabbit haemorrhagic disease (RHD) (GI.1 and GI.2) in the Iberian Peninsula have caused substantial economic losses in commercial rabbitries and have affected the conservation of rabbit-sensitive predators due to the dramatic decline of their natural populations. However, the assessment of the impact of both RHD strains on wild rabbit populations has been limited to a few small-scale studies. Little is known about the overall impact within its native range. In this study, we described and compared the effects of GI.1 and GI.2 countrywide by using time series of hunting bag data widely available across the country and compared their trend during the first eight years after the first outbreak of GI.1 (i.e., 1998) and GI.2 (i.e., 2011), respectively. We used Gaussian generalised additive models (GAM) with the number of hunted rabbits as the response variable and year as the predictor to evaluate the non-linear temporal dynamics of the population at the national and regional community levels. The first GI.1 caused a population decline of around 53%, affecting most Spanish regional communities where the disease occurred. The positive trend observed after GI.1 in Spain ended with the initial outbreak of GI.2, which did not appear to cause a national population decline. In contrast, we found significant variability in the rabbit population trend among regional communities, where some increased, and others decreased. Such a disparity is unlikely to be explained by a single factor; rather, it appears to result from several factors, such as climatic conditions, host resistance improvement, virulence attenuation, or population density. Our study suggests that a national comprehensive hunting bag series could aid in elucidating the differences in the impact of emerging diseases on a large scale. Future research should focus on national longitudinal serological studies to shed light on the immunological status of rabbit populations in different regions to better understand the evolution of RHD strains and the resistance gained by the wild populations.

Vole outbreaks may induce a tularemia disease pit that prevents Iberian hare population recovery in NW Spain.

Iberian hare populations have suffered severe declines during recent decades in Spain. Between 1970 and 1990s, a rapid increase in irrigation crop surface in NW Spain (Castilla-y-León region) was followed by a common vole massive range expansion and complete colonization of lowland irrigated agricultural landscapes from mountainous habitats. The subsequent large cyclic fluctuations in abundance of colonizing common voles have contributed to a periodic amplification of Francisella tularensis, the etiological agent that causes human tularemia outbreaks in the region. Tularemia is a fatal disease to lagomorphs, so we hypothesize that vole outbreaks would lead to disease spill over to Iberian hares, increasing prevalence of tularemia and declines among hare populations. Here we report on the possible effects that vole abundance fluctuations and concomitant tularemia outbreaks had on Iberian hare populations in NW Spain. We analysed hare hunting bag data for the region, which has been recurrently affected by vole outbreaks between 1996 and 2019. We also compiled data on F. tularensis prevalence in Iberian hares reported by the regional government between 2007 and 2016. Our results suggest that common vole outbreaks may limit the recovery of hare populations by amplifying and spreading tularemia in the environment. The recurrent rodent-driven outbreaks of tularemia in the region may result in a "disease pit" to Iberian hares: at low host densities, the rate of population growth in hares is lower than the rate at which disease-induced mortality increases with increased rodent host density, therefore, keeping hare populations on a low-density equilibrium. We highlight future research needs to clarify tularemia transmission pathways between voles and hares and confirm a disease pit process.

Molecular detection of Ehrlichia spp. in ticks parasitizing wild lagomorphs from Spain: characterization of a novel Ehrlichia species.

BACKGROUND: Several species belonging to the genus Ehrlichia are considered pathogenic for animals and humans. Although wildlife are known to play an important role in the epidemiology of these bacteria, information on the role of wild lagomorphs in their sylvatic cycle is limited. Thus, the objective of the present study was to assess the occurrence of Ehrlichia spp. in ticks collected from wild lagomorphs in Spanish Mediterranean ecosystems. METHODS: A total of 1122 pooled ticks (254 pools) collected from 506 wild rabbits (Oryctolagus cuniculus) and 29 Iberian hares (Lepus granatensis) were analysed using a nested PCR assay targeting the partial groEL gene. Ehrlichia spp.-positive samples were further subjected to a second PCR assay targeting 16S rRNA. RESULTS: Three (1.2%) tick pools comprising Rhipicephalus pusillus collected from nine wild rabbits were positive for Ehrlichia spp. All the Ehrlichia DNA sequences were identical, and use of sequence and phylogenetic analyses allowed us to identify a novel Ehrlichia species. CONCLUSIONS: We provide evidence that a novel Ehrlichia species, named herein as 'Candidatus Ehrlichia andalusi', which may be of concern for animal and public health, is circulating in R. pusillus in Spanish Mediterranean ecosystems. Further studies are warranted to assess the epidemiology, pathogenicity and zoonotic potential of this Ehrlichia species.

Unravelling the Role of Metabolites for Detecting Physiological State of Wild Animals: European Rabbit's (Oryctolagus cuniculus) Case.

European wild rabbit (Oryctolagus cuniculus) has been defined as a keystone species in the Mediterranean ecosystem. Rabbits have been classed as "endangered" by the IUCN within their native range. In this sense, animal nutrition may play a fundamental and limiting role in the conservation of wild species. The overarching goal of ecological nutrition is to unravel the extensive web of nutritional links that direct animals in their interactions with their ecological environments. The main aim of this work was to evaluate the effect of different feed intake, geographic location, animal sex, and reproductive stage on glucose, non-esterified fatty acids (NEFA), and plasmatic urea nitrogen (PUN), albumin, glutamate, and total protein metabolites. Additionally, we examined the potential of these metabolites as biomarkers. Full stomach contents and blood samples were collected from European wild rabbits (n = 89) for the analysis of the metabolites described above. Our work shows that the levels of these metabolites are affected by the sex of the animals, as well as by their reproductive stage (glucose, NEFA and albumin). There were signs of better optimisation of resources by females than by other groups of animals. These data may be interesting in the study of nutritional components that could be affecting physiological state of this species.

Nutritional Metabolites as Biomarkers of Previous Feed Intake in European Rabbit (Oryctolagus cuniculus): Applications on Conservation.

European wild rabbit (Oryctolagus cuniculus) populations have drastically reduced, and recently, rabbits have been classed as "endangered" by the IUCN. This animal plays an important ecological role in Mediterranean ecosystems and its introduction could significantly contribute to ecological restoration. Rabbits have high nutrient requirements that apparently cannot be covered in all ecosystems, and there are clues that nutrition can limit their abundance and density. On the other hand, some studies reflect the effects of food availability on the metabolomic status of other animal species, but there are no specific studies on this keystone species. The main aim of this work is to find biomarkers to assess the previous levels of ingestion of European rabbits (Oryctolagus cuniculus). To address this gap, gastric content and blood samples were collected from European rabbits (n = 99) in a Mediterranean area for the analysis of glucose, non-esterified fatty acids (NEFA), plasmatic urea nitrogen (PUN), albumin, glutamate and total protein metabolites. Depending on their previous feed intake (gastric content and the ratio between the gastric content and the weight of the animal), the animals were divided into two groups (lower and normal previous feed intake). Our work shows that the metabolomic profiles of the animals were affected. Levels of glucose (+82%; p = 0.0003), NEFA (−61%; p = 0.0040) and PUN (+139%; p < 0.001) were different in the animals with lower previous feed intake than the animals with normal previous feed intake. This work summarises that metabolic phenotype can be interesting when seeking to discover the limiting nutrients and food availability in diets that could affect the ecological fitness and conservation of European wild rabbits. It is important to mention that in this work, only the effects on six different metabolites have been analysed and more studies are necessary to complement the knowledge of possible metabolites that indicate the level of ingestion in this species and others. These (and new) biomarkers could be used as a tool to provide information about individual or population characteristics that other physiological parameters cannot detect, improving the conservation physiology field.

Molecular identification of zoonotic Rickettsia species in Ixodidae parasitizing wild lagomorphs from Mediterranean ecosystems.

A survey study was carried out to identify tick species parasitizing wild lagomorphs in Mediterranean ecosystems in southern Spain and to determine the occurrence of Rickettsia species present in these ticks in this region. A total of 1304 European wild rabbits (Oryctolagus cuniculus) and 58 Iberian hares (Lepus granatensis) were individually examined for the presence of ticks. Ticks were found in 42.9% and 50% of the wild rabbits and hares sampled, respectively. A total of 1122 ticks were collected and five species, including Rhipicephalus pusillus, Hyalomma lusitanicum, Haemaphysalis hispanica, Ixodes ventalloi and Rhipicephalus sanguineus sensu lato (s.l.), were microscopically and molecularly identified at the 16S rRNA gene. This is the first study on Ixodidae parasitizing Iberian hares. The presence of Rickettsia DNA was assessed in 254 tick pools (according to hunting states, lagomorph species, tick species and tick development stage) using PCR assays targeting the rOmpA, rOmpB and gltA. Twenty-seven pools (10.6%) were positive to Rickettsia DNA. Five zoonotic Rickettsia species were identified, being Rickettsia massiliae the most frequent (4.7%), followed by Rickettsia sibirica subsp. mongolitimonae (2.8%), Rickettsia slovaca (2.0%), Rickettsia aeschlimannii (0.8%) and Rickettsia africae (0.4%). The results suggest that wild rabbits and Iberian hares are parasitized by a wide range of tick species and that these lagomorphs may play an important role in the sylvatic cycle of some zoonotic Rickettsia species in Mediterranean ecosystems. Our data represent the first report of R. massiliae, R. aeschlimannii, R. slovaca and R africae in ticks collected in wild lagomorphs in Europe, and the first report of not imported R. africae in this continent. Since R. slovaca and R. africae DNA was detected in tick species different to their main vectors, further studies are warranted to unravel the role of wild lagomorphs in the epidemiology of these vector-borne pathogens.

Lack of evidence for differences in the spread of classic (Lagovirus europaeus/GI.1) and novel (Lagovirus europaeus/GI.2) rabbit haemorrhagic disease viruses in Europe and North Africa.

BACKGROUND: Fast-spreading diseases affecting wildlife populations threaten biodiversity. Two caliciviruses, Lagovirus europaeus/GI.1 and Lagovirus europaeus/GI.2, caused rabbit haemorrhagic disease virus (RHDV) in wild rabbits. Despite having different characteristics, these variants spread quickly, posing a threat to wild rabbit populations. METHODS: In this study, we conducted a thorough review of the scientific literature and reports of international organisations of first detections of both variants of RHDV in the Euro-Mediterranean region. We concentrated on this area to avoid bias due to intentional human introductions. RESULTS: The estimated mean spread rate of GI.2 was higher than that of GI.1 (GI.2: 479 km/year, range: 47-7346; GI.1: 330 km/year, 37-6248). These differences were not statistically significant. This lack of difference may be due to the interactions between each variant's virulence characteristics. Humans may have a dominant effect on their spread. Potential limitations associated with the observational process could have hindered our ability to identify statistical differences. CONCLUSIONS: The lack of difference in the spread patterns of the two variants could be due to a biological cause, human facilitation or a lack of statistical power. Adapting protocols to detect diseases in wildlife using homogeneous criteria will be indispensable in the coming years.

Spatiotemporal monitoring of Cysticercus pisiformis in European wild rabbit (Oryctolagus cuniculus) in Mediterranean ecosystems in southern Spain.

Cysticercosis in wild lagomorphs is caused by Cysticercus pisiformis, the larval stage of Taenia pisiformis. Although previous studies have reported the presence of T. pisiformis in different wild carnivore species, information about the prevalence of C. pisiformis in their intermediate hosts is still very scarce. An epidemiological surveillance program was carried out to determine the prevalence and spatiotemporal patterns of cysticercosis in wild rabbits (Oryctolagus cuniculus) from Spanish Mediterranean ecosystems. A total of 2,923 animals were sampled in 164 hunting estates from Andalusia (southern Spain) during four study periods: 2009-2012 (P1), 2012-2015 (P2), 2015-2018 (P3) and 2018-2020 (P4). The presence of cysticerci was assessed by macroscopical examination and a subset of the collected parasites were molecularly identified by conventional PCR targeting the ITS-1 and 12S rRNA partial genes of Taenia spp. Risk factors associated with cysticercus infection were assessed by generalized estimating equation (GEE) analysis. A spatial statistical analysis was carried out using a Bernoulli model to identify statistically significant spatial clusters. Cysticercus infection was confirmed in 81 (2.8 %; 95 % CI: 2.2-3.4) rabbits. Cysticerci from 18 infected animals were molecularly identified as T. pisiformis. The GEE model showed the study period as the only risk factor associated with C. pisiformis infection in wild rabbits. Significantly higher prevalence was found in P2 (6.1 %; 95 % CI: 4.4-8.4) compared to the rest of the periods. At least one cysticerci-positive animal was detected in 41 (25.0 %; 95 % CI: 18.4-31.6) out of the 164 hunting estates. No statistically significant spatial clusters of high cysticercus prevalence were identified. Our results indicate an endemic circulation of C. pisiformis in wild rabbits in southern Spain. The spatial results highlight a widespread distribution of this parasite in their populations. Further studies should focus in determining which sympatric species may act as definitive hosts for T. pisiformis and the relevance of other potential intermediate host species (e.g. hares and rodents), as the relevance of wild rabbits in the sylvatic cycle of this cestode in Mediterranean ecosystems seems to be low.

Spillover event of recombinant Lagovirus europaeus/GI.2 into the Iberian hare (Lepus granatensis) in Spain.

Viruses that affect lagomorphs have decades of reported history of spillover events. One of these viruses is the causative agent of the so-called rabbit or 'lagomorph' haemorrhagic disease (e.g. Lagovirus europaeus/GI.1 and L. europaeus/GI.2). In particular, L. europaeus/GI.2 has shown a great capacity to recombine with existing lagoviruses. In fact, it has replaced the former GI.1 genotype in the wild, and recently, an increase on spillover events has been detected among several lagomorph species including European and North American species of hares. In this study, we report for the first time the infection of a wild Iberian hare with GI.2 (RHDV2/b), potential shedding and associated histopathological alterations. We identify the recombinant GI.4P-GI.2 as causative of the infection and discuss plausible causes regarding the origin of the spillover event and its potential consequences for the Iberian hare wild populations, which is an endemic species of the Iberian Peninsula as well as an important game and prey species for many predators, including endangered species.

Individual fate and gut microbiome composition in the European wild rabbit (Oryctolagus cuniculus).

Studies connecting microbiome composition and functional performance in wildlife have received little attention and understanding their connections with wildlife physical condition are sorely needed. We studied the variation in gut microbiota (hard fecal pellets) between allopatric subspecies of the European wild rabbit in wild populations and in captured individuals studied under captivity. We evaluated the influence of environmental and host-specific factors. The microbiome of wild rabbit populations reduced its heterogeneity under controlled conditions. None of the host-specific factors tested correlated with the microbiota composition. We only observed significant intra-group dispersion for the age factor. The most diverse microbiomes were rich in Ruminococcaceae potentially holding an enriched functional profile with dominance of cellulases and xylanases, and suggesting higher efficiency in the digestion of fiber-rich food. Conversely, low diversity gut microbiomes showed dominance of Enterobacteriaceae potentially rich in amylases. We preliminary noticed geographical variations in field populations with higher dominance of Ruminococcaceae in south-western than in north-eastern Spain. Spatial differences appeared not to be subspecies driven, since they were lost in captivity, but environmentally driven, although differences in social structure and behavior may also play a role that deserve further investigations. A marginally significant relationship between the Ruminococcaceae/Enterobacteriaceae ratio and potential life expectancy was observed in captive rabbits. We hypothesize that the gut microbiome may determine the efficiency of feeding resource exploitation, and can also be a potential proxy for life expectancy, with potential applications for the management of declining wild herbivorous populations. Such hypotheses remain to be explored in the future.

Worldwide rapid spread of the novel rabbit haemorrhagic disease virus (GI.2/RHDV2/b).

We describe the extremely rapid worldwide spread of the Lagovirus europaeus/GI.2/RHDV2/b (henceforth GI.2), the causative infectious agent of the so-called 'novel' rabbit haemorrhagic disease of the European rabbit (Oryctolagus cuniculus). We tracked down all novel confirmed detections of GI.2 between May 2010 and November 2018 by carrying out a two-step in-depth review. We suggest that such spread would not have been possible without anthropogenic involvement. Our results also point out the importance of reviewing and adapting the protocols of virus detection and management in order to control, mitigate and contain properly, not only GI.2, but also new viruses that may emerge in the future.

GI.1b/GI.1b/GI.2 recombinant rabbit hemorrhagic disease virus 2 (Lagovirus europaeus/GI.2) in Morocco, Africa.

Rabbit hemorrhagic disease virus (RHDV) is highly lethal to the European rabbit (Oryctolagus cuniculus). It was first reported in 1984 in China, but in 2010, a new variant of the virus was detected (GI.2) in France. Several recombination events with pathogenic and non-pathogenic strains have been described. Here, we report the first sequences of RHDV in Africa, isolated from Moroccan rabbits, and these resemble GI.1b/GI.1b/GI.2 recombinants found in the Iberian Peninsula. Monitoring and characterization of strains from future outbreaks are advised to guarantee the success of current programs on small-rabbit production for poverty alleviation in African countries.

A large-scale assessment of European rabbit damage to agriculture in Spain.

BACKGROUND: Numerous small and medium-sized mammal pests cause widespread and economically significant damage to crops all over the globe. However, most research on pest species has focused on accounts of the level of damage. There are fewer studies concentrating on the description of crop damage caused by pests at large geographical scales, or on analysis of the ecological and anthropogenic factors correlated with these observed patterns. We investigated the relationship between agricultural damage by the European rabbit (Oryctolagus cuniculus) and environmental and anthropogenic variables throughout Spain. RESULTS: Rabbit damage was mainly concentrated within the central-southern regions of Spain. We found that rabbit damage increased significantly between the early 2000s and 2013. Greater losses were typical of those areas where farming dominated and natural vegetation was scarce, where main railways and highways were present, and where environmental conditions were generally favourable for rabbit populations to proliferate. CONCLUSION: From our analysis, we suggest that roads and railway lines act as potential corridors along which rabbits can spread. The recent increase in Spain of such infrastructure may explain the rise in rabbit damage reported in this study. Our approach is valuable as a method for assessing drivers of wildlife pest damage at large spatial scales, and can be used to propose methods to reduce human - wildlife conflict. © 2017 Society of Chemical Industry.