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The incidence of West Nile fever (WNF) is highly variable in emerging areas, making it difficult to identify risk periods. Using clinical case records has important biases in understanding the transmission dynamics of West Nile virus (WNV) because asymptomatic infections are frequent. However, estimating virus exposure in sentinel species could help achieve this goal at varying spatiotemporal scales. To identify the determinants of inter-annual variation in WNV transmission rates, we designed a 15-year longitudinal seroepidemiological study (2005–2020) in five environmentally diverse areas of southwestern Spain. We modeled individual annual area-dependent exposure risk based on potential environmental and host predictors using generalized linear mixed models. Further, we analyzed the weight of predictors on exposure probability by variance partitioning of the model components. The analysis of 2418 wild ungulate sera (1168 red deer - Cervus elaphus - and 1250 Eurasian wild boar - Sus scrofa) with a highly sensitive commercial blocking ELISA identified an average seroprevalence of 24.9% (95% confidence interval (CI): 23.2–26.7%). Antibody prevalence was slightly higher in wild boar (27.5%; CI: 25.1–30.1%) than in deer (22.2%; CI: 19.8–24.7%). We observed a spatial trend in exposure, with higher frequency in the southernmost areas and a slight, although area-dependent, increasing temporal trend. Host-related predictors were important drivers of exposure risk. The environmental predictor with the highest weight was annual cumulative precipitation, while temperature variations were also relevant but with less weight. We observed a coincidence of spatiotemporal changes in exposure with the notification of WNF outbreaks in horses and humans. That indicates the usefulness of wild ungulates as sentinels for WNV transmission and as models to understand its spatiotemporal dynamics. These results will allow the development of more accurate predictive models of spatiotemporal va

Understanding the dynamics of a wildlife population in relation to hunting strategies is essential to achieve sustainable management. We used monitoring data over 25 years from two red deer (Cervus elaphus) populations with different management (with and without supplemental feeding) in South Central Spain to: (i) characterise the density dependence of population dynamics under contrasted management, and (ii) provide the basis for sustainable extraction by considering the theoretical maximum sustainable yield (MSYt) as the reference. The red deer population displayed a typical management reactive culling approach (‘saw-tooth-like’ curves), with occasional strong annual harvests but not occurring on a regular basis. Interestingly, we found reduced population growth at high densities in both populations, indicating that density-mediated factors determined population growth even when artificial feeding was provided. However, no effects of sex not age class of the extracted population on the population growth rate were determined. The total number of animals hunted was only slightly above those predicted by MSYt (i.e. K50%) in both populations, despite high densities close to theoretical K, being consistent throughout the study period. The extraction rates (30.3 and 34.0%, for supplemented and unsupplemented populations, respectively) were 13.3% and 10.2% lower compared to the MSYt situation in the unsupplemented and supplemented populations, respectively. Long term population monitoring data provided feasible and suitable baseline values to optimise the sustainable exploitation of red deer populations in the Mediterranean ecosystem under these contrasting management scenarios. Adaptive management, involving objective-driven decision making informed by data on red deer population dynamic, can contribute (i) to maximising the total extraction over the long term while (ii) reducing the ecological impact of high population densities.

Crimean-Congo haemorrhagic fever virus (CCHFV) continues to cause new human cases in Iberia while its spatial distribution and ecological determinants remain unknown. The virus remains active in a silent tick-animal cycle to which animals contribute maintaining the tick populations and the virus itself. Wild ungulates, in particular red deer, are essential hosts for Hyalomma ticks in Iberia, which are the principal competent vector of CCHFV. Red deer could be an excellent model to understand the ecological determinants of CCHFV as well as to predict infection risks for humans because it is large, gregarious, abundant and the principal host for Hyalomma lusitanicum. We designed a cross-sectional study, analysed the presence of CCHFV antibodies in 1444 deer from 82 populations, and statistically modelled exposure risk with host and environmental predictors. The best-fitted statistical model was projected for peninsular Spain to map infection risks. Fifty out of 82 deer populations were seropositive, with individual population prevalence as high as 88%. The highest prevalence of exposure to CCHFV occurred in the southwest of the Iberian Peninsula. Climate and ungulate abundance were the most influential predictors of the risk of exposure to the virus. The highest risk regions were those where H. lusitanicum is most abundant. Eight of the nine primary human cases occurred in or bordering these regions, demonstrating that the model predicts human infection risk accurately. A recent human case of CCHF occurred in northwestern Spain, a region that the model predicted as low risk, pointing out that it needs improvement to capture all determinants of the CCHFV infection risk. In this study, we have been able to identify the main ecological determinants of CCHFV, and we have also managed to create an accurate model to assess the risk of CCHFV infection.

Flaviviruses of the Japanese Encephalitis complex such as West Nile (WNV) and Usutu (USUV) viruses are emerging as causes of viral meningoencephalitis cases in animals and humans in Spain. Wild birds are natural reservoirs for WNV and USUV and, in liaison with competent mosquitoes, responsible for their maintenance and transmission. However, the intimate link between wild birds, domestic animals (horses), mosquitoes and humans in continental Spain is not yet well understood. With the goal of better understanding the ecology of flaviviruses at the wildlife-livestock-human interface, we captured birds in 2018/2019 in a decreasing wildlife-livestock interaction gradient in 5 horse farms. Birds were captured with mist nets at three sites per farm: (1) the farm; (2) a site 500-1,000m away from the farm; and (3) a site at a 3-5 km distance from the farm without livestock. We collected blood from the brachial vein, oral and cloacal swabs, and growing feathers from captured birds(N=580). The presence of Flavivirus antibodies in bird sera was estimated by a multispecies blocking ELISA that is highly specific for WNV, whereas a duplex quantitative real-time reverse transcription PCR allowed detecting Flavivirus infection. Twenty-eight of 451 sera were positive (6.2%) and the highest proportion of positives occurred in the farms (8.1%) in comparison to sites 2 and 3 (4.6% and 5.8%, respectively). Four of the 503 PCR tests (feathers/swabs) were positive (0.8%) but only one sample (Turdus merula) could be confirmed by sequencing as USUV (99.6% homology). PCR positive birds were only found in sites 1 and 2. These findings confirm the active circulation of flaviviruses in continental Spain and, especially, close to horse farms. The interaction with wild birds is high in the environment of the farms, so these results show that horses (and humans) are at risk of developing viral meningoencephalitis caused by WNV.

Deer venison is increasingly valued as a natural meat. This study examines the three main sources of venison: farmed venison from New Zealand (NZ), the world’s leading producer, and wild deer from Spain (SP), the second largest producer, which mainly supplies venison from traditional autumn–winter driven hunts (monteria), involving packs of dogs, and a smaller proportion culled through summer selective stalking. Meat from NZ contained more protein, lower shear force and lower n-6/n-3 ratio (P < 0.01). Spanish meat had a greater content of total, essential and non-essential amino acids (P < 0.01). Meat from deer culled in winter had lower intramuscular fat and saturated fatty acids (FA) but higher polyunsaturated FA (P < 0.01) and pH (P < 0.001) than meat from summer stalked deer. Therefore, venison presents differences by country of origin for composition, FA and texture that are likely to affect its health characteristics. Anomalies observed in meat between the winter driven hunt and non-stressful summer stalking may be attributed to the level of death stress in the case of variables such as pH. However, the effect on fat and mineral composition seems to be seasonal, depending respectively on wild diet or cyclic osteoporosis in males.

The current demographic expansion of red deer populations in the northern hemisphere has led to conflicts at the levels of health, the economy, and conservation. Potential tools for deer management include the delivery of contraceptives that impair reproduction in order to control populations or the delivery of treatments/vaccines in order to control health. To successfully implement these control strategies, it is necessary to develop suitable methods with which to deliver treatments to red deer in field settings. The objectives of this study were (i) to evaluate the specificity and palatability of three bait types—alfalfa, feed, and molasses-based—for red deer (Cervus elaphus) and (ii) to describe the constraints that limit or enhance the effectiveness of the bait deployment method—on the ground or in specific red deer feeders—for the oral delivery of treatments to red deer in Mediterranean ecosystems. Our results show that alfalfa baits are the least palatable but the most deer-selective type of bait, whereas feed and molasses baits are highly palatable but low specific (mean bait consumption rates on the ground were 0.811, 0.949, and 0.955, respectively). The appropriate season for oral treatments using alfalfa baits both on the ground and in deer feeders is late summer (mean bait consumption rate on the ground for alfalfa-based baits was 0.939 in summer period). These results indicate that alfalfa baits are sufficiently palatable and specific in summer for them to be an efficient means to deliver treatments to red deer in Mediterranean ecosystems.

[Context]: Supplemental feeding of large mammalian herbivores is a common management tool mainly aimed at promoting healthy populations and at increasing productivity and trophy sizes. Such management measure may indirectly affect herbivore effects on plant communities through altered foraging patterns. The quantification of the ecological effects of large herbivore management is important for designing holistic management and conservation programs. [Aims]: Here we aimed at quantifying the ecological effects of supplemental feeding of Iberian red deer, Cervus elaphus hispanicus, on the composition of and on the browsing effects on Mediterranean woody plant community. [Methods]: An experiment was set up in a hunting rangeland located in central Spain, where female deer were kept in enclosures with either exclusive access to natural forages or with additional ad libitum access to a nutritionally rich concentrate. The experiment also included a control area where deer were absent. [Key results]: We observed significant differences in browsing impacts among the supplemented, non-supplemented and control areas, and such effect varied for the different plant species. Plant species which nutritional content complemented that of fodder were more highly consumed, for instance, Erica spp., which digestible fibre content is higher and N content lower than that of provided fodder. The presence of deer and the concentrate supplied, instead, did not influence the relative abundances of shrub species. [Conclusions]: Artificial supplemental feeding provided to ungulates led to increased browsing on plant species which nutritional composition complemented that of the supplement provided. [Implications]: So as to alleviate herbivory impact on all shrubs, we suggest that composition of supplemental feeding should adjust both to the natural forage availability and quality and to ungulate requirements across seasons.

[Objectives]: Host individual, host population and environmental factors interact to modulate parasite abundance in hosts. Since size dimorphism, life history traits and segregation observed in red deer (Cervus elaphus) are linked to sex and this ungulate species constitutes a highly relevant host for adult exophilic ticks, it was hypothesized that tick parasitism on stags and hinds would be differentially influenced by each of these factors. [Method]: Ticks from 306 red deer were collected during 7 years in a red deer population. By generalized linear models we modelled tick abundance on deer with 20 potential predictors. Three models were developed: one for stags, another for hinds, and one combining data from both sexes and including >sex> as factor. Our rationale was that if tick burdens on males and hinds relate to the explanatory factors in a differential way, it is not possible to precisely and accurately predict the tick burden on one sex using the model fitted on the other sex, or with the model that combines data from both sexes. Our results showed that deer males were the primary target for ticks, the weight of each factor differed between sexes, and each sex specific model was not able to accurately predict burdens on the animals of the other sex. [Conclusions]: Results support for sex-biased differences in tick parasitism in red deer. The higher weight of host individual and population factors in the model for stags show that intrinsic deer factors more strongly explain tick burden than environmental host-seeking tick abundance. In contrast, environmental variables better explained tick burdens in hinds.

The interactions between host individual, host population, and environmental factors modulate parasite abundance in a given host population. Since adult exophilic ticks are highly aggregated in red deer (Cervus elaphus) and this ungulate exhibits significant sexual size dimorphism, life history traits and segregation, we hypothesized that tick parasitism on males and hinds would be differentially influenced by each of these factors. To test the hypothesis, ticks from 306 red deer-182 males and 124 females-were collected during 7 years in a red deer population in south-central Spain. By using generalized linear models, with a negative binomial error distribution and a logarithmic link function, we modeled tick abundance on deer with 20 potential predictors. Three models were developed: one for red deer males, another for hinds, and one combining data for males and females and including >sex> as factor. Our rationale was that if tick burdens on males and hinds relate to the explanatory factors in a differential way, it is not possible to precisely and accurately predict the tick burden on one sex using the model fitted on the other sex, or with the model that combines data from both sexes. Our results showed that deer males were the primary target for ticks, the weight of each factor differed between sexes, and each sex specific model was not able to accurately predict burdens on the animals of the other sex. That is, results support for sex-biased differences. The higher weight of host individual and population factors in the model for males show that intrinsic deer factors more strongly explain tick burden than environmental host-seeking tick abundance. In contrast, environmental variables predominated in the models explaining tick burdens in hinds.

Although Mycobacterium bovis infection is commonly reported in red deer (Cervus elaphus), potential differences in the effects of infection on male and female animals in terms of body condition and clinical biochemistry have not been reported. Between November 2000 and January 2006, serum and biometrical data were collected post-mortem from 88 red deer.M. bovis-infected deer, particularly males, were typically older, heavier and in poorer body condition than uninfected animals. Serum triglyceride, cholesterol (both particularly in males) and total protein concentrations were lower, whereas serum creatinine (more evident in females), and immunoglobulin G and M concentrations were higher in the infected deer. These sex-related differences in the response to M. bovis infection in red deer should be considered when undertaking epidemiological assessments and designing disease control strategies as they may reflect differing roles of male and female animals as potential reservoirs or disseminators of disease.

Body condition is a useful measure of the nutritional status and performance in ungulates. The most widely used indicators of body condition are based on fat reserves, mainly those surrounding the kidneys. To estimate the body condition in large herbivores, researchers often collect and pool the data from both kidneys and their perirenal fat in order to compensate for potential differences between the body condition indicators obtained from the left and right kidneys. Since these differences do not seem to be properly established in wildlife, we checked for the potential differences between the body condition indicators, derived from both kidneys, in wild ungulates. In the present study, we used red deer Cervus elaphus, both under experimental and field conditions, as a model to analyse the patterns of response of the body condition indicators, calculated from left and right kidneys, to supplementary feeding, sex, age class and season. By considering two analytical approaches-kidney fat index and fat weight (including kidney weight as a covariate)-we consistently obtained similar statistical results and the same ecological interpretations by using left, right and average indicators for all the factors tested. In the experimental study, supplementary feeding had a significant effect on all the body condition indicators of red deer hinds. Under field circumstances, the condition indicators were statistically higher in females than in males and they increased with age. Sex related differences were significant in the winter. Taking into account our results, we hypothesize that information from only one kidney will be enough to assess the body condition in red deer and probably in other wild ungulates. However, a standardized sample (i.e. always using the same kidney and associated fat) should be used, while a better understanding regarding possible asymmetries in the amount of the energy reserves on each side of the animals' bodies has not been reached. Our study has cl

We attempted to determine why after an exceptionally hard winter deer antlers fractured more often than usual. We assessed mechanical properties, structural variables and mineral composition of deer antlers grown in a game estate (LM) after freezing temperatures (late winter frosts, LWF), which resulted in high incidence of antler fractures despite being grown later in the year, and those grown after a standard winter (SW). Within each year, specimens from broken and intact antlers were assessed. LWF was associated with reduced impact energy (U) and somewhat reduced work to peak force (W), Young's modulus (E) and physical density, as well as cortical thickness. LWF was associated with considerably increased Si and reduced Na. In each year, broken antlers had lower Mn, P and physical density, and they had more Na and B than unbroken antlers. Because no such effect was found in farmed deer fed whole meal, and because freezing in plants usually produces an increase in Si content, which in turn reduces Mn, it is likely that LWF produced a diet rich in Si and low in Mn. Because antlers are grown transferring calcium phosphate from the own skeleton and Ca/P levels were slightly reduced, it seems likely that Mn reduction may have increased antler fractures. A comparison between farm deer and those in another game estate (LI) also shows a link between lower Mn content and lower W. Thus, small changes in minor bone minerals, probably induced by diet, may have marked effects in mechanical properties of bone.

The influence of short- and long-term (cohort) effects of climate and density on the life-histories of ungulates in temperate regions may vary with latitude, habitat, and management practices, but the life-histories of ungulates in the Mediterranean region are less well known. This study examined the short- and long-term effects of rainfall and absolute density on hinds in two of the southernmost populations of red deer (Cervus elaphus hispanicus) in Europe. One population received supplementary forage. Unlike more northerly latitudes, where red deer hinds lose body mass in winter as a result of adverse weather, in the Spanish populations, hinds did not lose body mass. Hinds in the population that received supplementary forage were heavier and more likely to become pregnant than were the hinds in the unsupplemented population. The likelihood of pregnancy occurring was strongly influenced by hind body mass; the proportion of yearlings that became pregnant was consequently lower in the unsupplemented population than in the population that received supplementary forage. Cohort effects on hind body mass (negative for density and positive for rainfall at birth) and on the probability of pregnancy (negative for density at birth) were apparent only in the unsupplemented population, which implies that supplemental feeding may partially compensate for negative density-dependent factors during early growth, and that supplemented deer hinds may experience reduced selection pressures. These results reflect the particular seasonal variation in the abundance and quality of food in Mediterranean habitats. The delayed effects of climate and density at birth on adult hind body mass and the prevalence of pregnancy probably affects population dynamics and constitutes a mechanism by which cohort effects affect the population dynamics in Iberian red deer. The management of Iberian red deer populations should take into account cohort effects and supplemental feeding practices, which can

The major histocompatibility complex (MHC) contains the most variable functional genes described in vertebrates. Individuals from natural populations deal constantly with a diverse range of pathogens and the polymorphism at MHC loci is what determines the diversity of foreign antigens that the host immune system can recognize. Polymorphism at individual loci may result in variable MHC class II (MHC-II) haplotypes. We characterized for the first time, the allelic diversity at the second DRB locus of the MHC-II in the Iberian red deer Cervus elaphus hispanicus. The studied population was sampled from a fenced estate that has been managed for hunting purposes and may provide information of the effect of game management on the genetic diversity of this species. Deer presented high levels of variation at MHC-II DRB-2 with 18 different alleles detected in 94 individuals. However, a significant heterozygous deficiency was found for MHC-II DRB-2 locus (92.5% of individuals only amplified one allele), whereas genotype frequencies at three neutral microsatellite loci were according to Hardy–Weinberg equilibrium, with heterozygosity over 50%. The analysis of control Iberian red deer from different geographic locations identified two expressed DRB-2 loci with a high degree of heterozygosis. The annual diversity index of MHC-II DRB-2 alleles significantly decreased along the 16-year study period, which was confirmed with losses in microsatellite markers. Although we cannot exclude positive non-assortative mating and/or substructured breeding (Wahlund effect) within our reference population, such unexpected apparent homozygosity at MHC DRB-2 loci is suggestive of null alleles occurring at our population. The observed pattern could be the result of a founder effect in this recently established population. Nonetheless, the loss of MHC-II DRB-2 allele diversity could reflect the effects of inbreeding in this fenced population managed for hunting. These findings support the importanc

Host genetic diversity plays an important role in buffering populations against pathogens. We characterized the allelic diversity at the second exon of the b (DRB-2) chain of the major histocompatibility complex class II (MHC-II) locus in a population of Iberian red deer (Cervus elaphus hispanicus) and its impact on parasitism by macroparasites, on a microparasite causing tuberculosis, and on relevant life history traits (spleen size and body condition)., No DRB-2 haplotype conferred general resistance or susceptibility against all parasites. However, specific significant correlations were found between some DRB-2 haplotypes and specific parasites. We also detected associations between DRB-2 haplotypes and body condition and spleen size after controlling for body size, sex and age. Our results evidenced a functional significance of MHC-II genes in the defence of Iberian red deer against parasites. These results also support a role of MHC-II as a fitness-enhancing genetic element which can be mediated by parasite effects on life traits with a genetic basis., We conclude that MHC immunogenetic studies may assess management decisions in Iberian red deer because (i) loss of genetic diversity may lead to increased disease occurrence, and (ii) MHC genes are ecologically relevant since they underlie host infection rates and life history traits.

Elaphostrongylus cervi (Nematoda, Metastrongyloidea) is an extrapulmonary lungworm of red deer (Cervus elaphus) whose first-stage larvae (L1) require terrestrial gastropods as intermediate hosts. The seasonal pattern of fecal excretion of E. cervi L1 in Iberian red deer (Cervus elaphus hispanicus) was monitored during three annual periods (June 2000–May 2003) on a hunting estate from south-central Spain. The lowest rates of mean intensity of fecal L1 were found in summer, whereas no seasonal variation was found for prevalence. Monthly intensity of excretion was positively associated with early rainfall (the next month) rather than with rainfall of the same month. This seasonal rhythm of E. cervi L1 discharge may be the result of parasite adaptation to the seasonal Mediterranean climate and habitat constraints to improve the chance of parasite transmission. We have standardized the sampling period to compare E. cervi L1 infection rates of Iberian red deer populations in Mediterranean Spain, a natural limit of both the parasite and deer historical ranges, for potential use in the assessment of management strategies.

Several theories predict offspring biases towards males or females with increasing reproductive resources of the mother to maximize reproductive returns by offspring, or as a result of prohibitive cost of the most expensive sex for young mothers or those in poor condition. This study examines foetus sex of 221 harvested hinds in a food-supplemented game estate for 10 years, according to hind age class (yearlings, subadults or adults), precise age, body mass and condition, and jaw length. A logistic model showed that hinds had a greater probability of bearing a male foetus with increasing age class, but not with any other variable. The greatest bias was found in yearling hinds. After controlling for age class and mass, jaw length was smaller in pregnant compared to non-pregnant yearlings and subadults, which suggests a trade-off between reproduction and growth. The bias towards females in yearlings increased as gestation proceeded, which suggests that the bias might be a result of selective abortion of male foetuses. Although results do not exclude an investment in males to increase number of grand-offspring, they suggest that young hinds may produce daughters as a trade-off between low energetic-cost offspring and their need to grow.

We studied the pattern of infection and the inter-annual variation and individual factors affecting the infection of 2 species of nasopharyngeal bot flies, Cephenemyia auribarbis and Pharyngomyia picta (Diptera: Oestridae), in a population of Iberian red deer (Cervus elaphus hispanicus) from south central Spain (10 annual periods between 1990 and 2003). Mean prevalence±S.E.95%CI of infection was 35·19±4·24% (n=486). The frequency distribution of the parasites was markedly aggregated (K: 0·213, mean abundance±S.D.: 5·49±12·12). Parasite load of Oestridae peaked at calf and subadult age groups and declined thereafter, which suggests that acquired immunity may be acting. In common with other host–parasite relationships, male hosts were found to have higher prevalence and abundance levels than females. The prevalence of P. picta was positively affected by the presence of C. auribarbis whereas the intensity of infection of P. picta was negatively affected by the presence of C. auribarbis. Intensity of P. picta in concomitant infections with C. auribarbis was lower than in pure P. picta infections, whilst the intensity of C. auribarbis infections did not change. This provides good evidence of interspecific competence, which could be dealt with by parasites by means of asynchronous life-cycles and different maturation periods. Weather also affects the dynamics and transmission rates of these parasites. Previous annual rainfalls positively affected the level of infection with oestrids. Yearly autumn rainfalls affected positively P. picta, possibly due to an effect on the pupal stage survival. Infection of Oestridae affected body condition in calves and subadults, suggesting that oestrids could have sublethal effects on Iberian red deer. Future research is needed to investigate the effect of parasites on the dynamics of the Iberian red deer.

[EN] Given that the introduction of allochthonous deer breeds in Spanish farms and hunting estates is becoming increasingly common, it is urgent to describe the morphology of Iberian red deer (Cervus elaphus hispanicus) antlers. We use over 2,000 cast antlers collected in Sierra Morena (southern Spain) to provide reference values for beam and first (brow) tine length, beam and burr circumference, and antler weight, depending on the number of antler points. In addition, this study includes a mean gross score of the trophy calculated according to the official formulae, as well as its correlation with the antler variables considered in this study. Beam length is the single most important factor for high score trophies, while factors such as antler weight or the number of antler points contribute little to the gross score. Management implications of these data are discussed., [DE] Da die EinbÜrgerung von allochthonen Rotwildunterarten in spanischen Jagdrevieren immer Üblicher wird, ist es wichtig die Morphologie des Geweihes bei der Iberischen Unterart (Cervus elaphus hispanicus) zu beschreiben. In der vorliegenden Studie werden Über 2000 Abwurfstangen aus der Sierra Morena (SÜdspanien) beschrieben. FÜr jede Endenzahl werden Referenzdaten Über Stangenlänge, Augsprossenlänge, Stangenumfang zwischen Aug- und Mittelsprosse, Rosenumfang und Gewicht angegeben. Weiterhin wird untersucht, wie diese Faktoren die offizielle Bewertung beeinflussen. Die Stangenlänge ist der wichtigste Fakor fÜr hochwertige Trophäen. Gewicht oder Endenzahl haben dagegen einen relativ geringen Einfluss. Die Management-Konsequenzen dieser Ergebnisse werden diskutiert.