Genetic effects and radioactive contamination of large mammals, including wild boar (Sus scrofa), have been studied in Japan because of dispersal of radionuclides from the Fukushima Dai-ichi Nuclear Power Plant in 2011. Such studies have generally demonstrated a declining trend in measured radiocesium body burdens in wildlife. Estimating radiation exposure to wildlife is important to understand possible long-term impacts. Here, radiation exposure was evaluated in 307 wild boar inhabiting radioactively contaminated areas (50–8000 kBq m⁻²) in Fukushima Prefecture from 2016 to 2019, and genetic markers were examined to assess possible germline mutations caused by chronic radiation exposures to several generations of wild boar. Internal Cs activity concentrations in boar remained high in areas near the power plant with the highest concentration of 54 kBq kg⁻¹ measured in 2019. Total dose rates to wild boar ranged from 0.02 to 36 μGy h⁻¹, which was primarily attributed to external radiation exposure, and dose rates to the maximally exposed animals were above the generic no-effects benchmark of 10 μGy h⁻¹. Using the estimated age of each animal, lifetime radiation doses ranged from <0.1 mGy to 700 mGy. Despite chronic exposures, the genetic analyses showed no significant accumulation of mutation events. Because wild boar is an occasional human dietary item in Japan, effective dose to humans from ingesting contaminated wild boar meat was calculated. Hypothetical consumption of contaminated wild boar meat from radioactively contaminated areas in Fukushima, at the per capita pork consumption rate (12.9 kg y⁻¹), would result in an average effective annual dose of 0.9 mSv y⁻¹, which is below the annual ingestion limit of 1 mSv y⁻¹. Additionally, a consumption rate of about 1.4 kg y⁻¹ of the most contaminated meat in this study would not exceed annual ingestion limits.

Extended-spectrum β-lactamases (ESBL)-producing Enterobacterales have been classified as critical priority pathogens by the World Health Organization (WHO). ESBL are universally distributed and, in 2006, were firstly reported on a wild animal. Understanding the relative contributions of wild animals to ESBL circulation in the environment is urgently needed. In this work, we have conducted a nationwide study in Portugal to investigate the occurrence of bacteria carrying clinically significant antimicrobial resistance genes (ARG), using widely distributed wild ungulates as model species. A total of 151 antimicrobial resistant-Enterobacterales isolates were detected from 181 wild ungulates: 50% (44/88) of isolates from wild boar (Sus scrofa), 40.3% (25/62) from red deer (Cervus elaphus), 41.4% (12/29) from fallow deer (Dama dama) and 100% (2/2) from mouflon (Ovis aries subsp. musimon). Selected isolates showed a diversified resistance profile, with particularly high values corresponding to ampicillin (71.5%) and tetracycline (63.6%). Enterobacterales strains carried blaTEM, tetA, tetB, sul2, sul1 or dfrA1 ARG genes. They also carried blaCTX₋M-type genes, which are prevalent in human infections, namely CTX-M-14, CTX-M-15 and CTX-M-98. Strikingly, this is the first report of CTX-M-98 in wildlife. Almost 40% (n = 59) of Enterobacterales were multi-drug resistant. The diversity of plasmids carried by ESBL isolates was remarkable, including IncF, K and P. This study highlights the potential role of wild ungulates as environmental reservoirs of CTX-M ESBL-producing E. coli and in the spill-over of AMR bacteria and their determinants. Our findings suggest that wild ungulates are useful as strategic sentinel species of AMR in terrestrial environments, especially in response to potential sources of anthropogenic pollution, providing early warning of potential risks to human, animal and environmental health.

Here we study the occurrence of abnormalities on bone tissue composition and turnover mechanisms through the Pb-mediated disruption of vitamins A and D in wild ungulates living in a lead (Pb)-polluted mining area. Red deer (Cervus elaphus) and wild boar (Sus scrofa) from the mining area had significantly higher liver and bone Pb levels than controls, which were associated with the depletion of liver retinyl esters and the corresponding increase of free retinol levels both in deer and boar from the mining area. Pb-exposed adult deer had lower carbonate content in bone mineral than controls, which was associated with the increased free retinol percentage. In wild boar, the degree of bone mineralization was also positively associated with higher burdens of retinyl esters. These results suggest that Pb-associated changes in bone composition and mineralization is likely influenced by the depletion of vitamin A in wildlife exposed to environmental Pb pollution.

This is the first field study to evaluate lead exposure in dogs fed game meat and offal and, to our knowledge, the first study exploring associations between game consumption and dog health status. We quantified lead concentrations in blood and hair and haematological parameters of 31 dogs fed game meat and offal from wild boar (Sus scrofa) and axis deer (Axis axis) culled with lead ammunition in El Palmar National Park, Argentina. Despite variable weekly frequency in game consumption, dogs had detectable blood and hair lead levels, demonstrating recent and chronic exposure. Lead geometric mean and SD were 18.91 ± 346.85 μg/dL w.w. in blood (range = 0.53–216.58), and 0.721 ± 6.444 μg/gr d.w. in hair (range = 0.007–34.800). Hair lead levels were relatively low in most samples, except for the oldest dog which had an atypically high value concurrent with anaemia, a common outcome of chronic lead exposure. Dog’s owner was significantly predictive of both blood and hair lead levels, which reflects the same feeding patterns for all dogs owned by the same person. Body condition was associated with hair lead, with dogs in good condition presenting higher lead levels. This could be related to greater game consumption by those dogs, resulting in higher lead ingestion. Dogs fed game meat and offal at very low or low frequency (≤4 times per week) showed higher blood lead levels, suggesting there might not be a risk-free frequency for game provision to dogs. Considering the risks of dietary lead exposure, avoiding feeding dogs lead-killed game and replacing lead ammunition with non-toxic alternatives are recommended. This would allow using hunted game as a valuable food resource without unnecessary risk for the health of consumers and the environment.

The role feral pigs (Sus scrofa) as a source of fecal contamination in Pacific Island ecosystems is not well understood. This study investigated the effects of feral pigs on enterococci (ENT) in runoff and soils of a Hawaiian forest. Seven sites were established with paired fenced/unfenced runoff plots in the Manoa watershed. Runoff was collected monthly from these plots after rain events from June 2008 to April 2009; soil ENT at each plot were also quantified. ENT in runoff were highly variable ranging from below the detection limit to >4.38 log10 most probable number (MPN) 100 mL−1. A repeated measures ANOVA found no overall fencing effects. This ANOVA did reveal a month by site interaction, indicating that while ENT in runoff were the highest in the wet season, this was not consistent across all sites. Soil ENT ranged from 14 to 511 MPN g−1 and differed among sites but not between fencing treatments. The only variables that were significantly correlated to ENT in runoff were runoff volume and soil ENT; slope, throughfall, soil moisture, bare soil cover, and total suspended solids in runoff were not correlated with ENT. While concentrations of ENT in runoff were highly variable across the months and sites, these forested headwaters did serve as sources of ENT to downstream ecosystems throughout the year. To minimize effects on human health, we recommend that public authorities employ greater warnings (i.e., signage) at streams and beaches in the lower reaches of this and other forested Hawaiian watersheds that are frequently used by both residents and tourists.

Contaminant monitoring in tissues of wild species can help in the knowledge not only of their health, but also of the environmental health conditions in the zones where they live. In this study, concentrations of toxic metals (As, Cd, Hg, and Pb) and an essential metal (Zn) were measured in the hair of red deer (Cervus elaphus) and wild boar (Sus scrofa) inhabiting in protected areas of South-Western Spain. Zn (69.02 ± 1.03 mg kg⁻¹, 70.31 ± 2.22 mg kg⁻¹), Pb (0.61 ± 0.05 mg kg⁻¹, 0.68 ± 0.08 mg kg⁻¹), and As (0.33 ± 0.03 mg kg⁻¹, 0.53 ± 0.08 mg kg⁻¹) were detected in the hair of red deer and wild boar, respectively. The other metals (Cd and Hg) were under the quantification limit (0.1 mg kg⁻¹). No differences in the level of elements between both species were found. The levels of the detected elements in the hair showed low concentrations and similar to those observed in animals of the same species from unpolluted zones, reflecting a lack of contamination by these elements in the studied areas. Based on critical values of these elements established for organs of mammals, red deer and wild boar from the studied territories did not suffer toxicosis by the studied elements. Age-related differences in the content of As in the hair of red deer and age- and gender-related differences in the content of As in the hair of wild boar were detected, which should be considered for biomonitoring purposes. Finally, positive (Pb-As in both species) and negative (Zn-Pb in wild boar) interrelationships between elements were found.

Consumption of meat from animals hunted with Pb ammunition can cause toxic accumulation with consequent health risks, even if relatively small amounts are consumed in each exposure. In El Palmar National Park, Argentina, invasive alien mammals, wild boar (Sus scrofa) and axis deer (Axis axis), are culled with Pb ammunition and their meat is consumed. In this study, we evaluated blood Pb concentrations in 58 consumers of culled game and examined Pb exposure risk according to their demographics, duty, and consumption habits. Likewise, the likelihood of exposure was evaluated by quantifying Pb concentrations in meat samples of seven culled axis deer. Twenty-seven participants (46%) had detectable blood Pb levels (limit of detection = 3.3 μg/dL), with an average 4.75 ± 1.35 μg/dL (geometric mean ± geometric S.D.); the average for all participants was 3.25 ± 1.51 μg/dL. Blood Pb concentrations were significantly higher in hunters, in participants who reported consuming game meat more than 5 times per week, and in participants who reported frequently consuming cured game meat (compared to cooked or pickled). Pb concentration varied significantly along the trajectory of the bullet in deer muscle, being highest at mid-point but with detectable Pb levels even in distant tissue samples (control), suggesting potential for dietary intake by consumers. These findings provide evidence of Pb exposure risk in consumers and emphasize the relevance of replacing Pb ammunition with non-toxic alternatives. This change would reduce dietary exposure in frequent consumers and allow the use of game meat as safe food for people whilst eliminating collateral risks to wild animals and the environment.

Environmental heterogeneity contributes to various habitats and may influence the diversity and activity patterns of wildlife among habitats. We used camera traps to assess wildlife habitat use in Guanyinshan Nature Reserve from 2009 to 2012. We focused on four types of habitat including open areas with gentle slope (<15°) (Type1), low elevation areas (about 1500–1700 m) with high bamboo coverage (Type2), high elevation areas (about 2100–2300 m) with high canopy coverage (Type3), and wildlife migration passages (Type4). We analyzed the differences in species richness, relative abundance index (RAI), species diversity, and animals’ activity pattern among habitats. Total six species were analyzed on activity pattern, which are Takin (Budorcas taxicolor), tufted deer (Elaphodus cephalophus), Himalayan goral (Naemorhedus goral), wild boar (Sus scrofa), golden pheasant (Chrysolophus pictus), and porcupine (Hystrix hodgsoni). The results are (1) that there were significant differences in richness and RAIₜ among habitats; (2) Type4 habitat had the highest richness and RAIₜ while Type2 had the highest species diversity; giant pandas were found in these two habitats; (3) there were significant differences in species’ activity during daytime and nighttime; and (4) differences appeared in habitat preference of the most abundant species. Takin and tufted deer preferred Type1, Himalayan goral preferred Type2, and golden pheasant preferred Type3. Type4 habitat was used by most animals. All these revealed that habitat heterogeneity plays an important role in species diversity and the importance for conservation.

The aim of this study was to evaluate the level of lead (Pb) in the livers and kidneys of free-living animals from Poland, with regard to the differences in tissue Pb content between the species. The research material consisted of liver and kidney samples collected from roe deer (Capreolus capreolus), red deer (Cervus elaphus), and wild boar (Sus scrofa) that had been hunted in 16 voivodeships of Poland. The concentration of lead had been measured using inductively coupled plasma optical emission spectrometry (ICP-OES) method. The results show that differences in lead concentration in the organs depended on the geographic location. In roe deer and red deer, the highest mean lead concentrations in the livers and kidneys, observed in the central region of Poland, were twice as high as the lowest concentration of Pb in these animals from the northeastern region of the country. In wild boar, the highest mean concentration of Pb was noted in the livers of animals from the central region of Poland and in the kidneys of animals from the northwestern region, while the lowest lead concentrations in both organs were typical for wild boar from the southeast part of the country. Our results show that areas located in the center and in the north of Poland carry most of the burden of lead bioaccumulation.

The aims of the present study were to investigate Pb and Cd levels in tissues of wild boar (Sus scrofa) from the Sierra Nevada Natural Space (SNNS) (southern Spain). Heavy metal concentrations in livers, kidneys and bones from 111 animals were determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Bones and kidneys were the most Pb- and Cd-contaminated tissues, respectively; Cd concentrations were 5.6 times higher in kidneys than in livers. This is the first biomonitoring study of these pollutants in wild boar tissues in the SNNS, and findings indicate that this population is chronically exposed to these heavy metals. The detected Pb and Cd concentrations were lower than those found in many studies performed in Europe on the same species.