European Journal of Wildlife Research最新文献

Increasing abundance of large ungulates is raising human-wildlife impacts and the effectiveness of recreational hunting to reduce their population growth is increasingly questioned. We report on long-term trends (> 15 years) in wildlife-vehicle collisions (WVC) and hunting bags, and on associations between the annual growth rate of WVC and that of hunting bags for three ungulates – the wild boar, the red deer, and the roe deer – and the grey wolf in northwest Spain to evaluate the regulating capacity of recreational hunting at large spatial scale. Wildlife-vehicle collisions increased by 332% in 16 years and 91% of all traffic accidents were caused by collisions with these three ungulates. All ungulate species showed significant positive trends in WVC and hunting bags, but we did not observe a negative association between annual growth rate of hunting bags and that of WVC except for the wild boar. Results suggest that recreational hunting was unable to reduce ungulate population growth at the regional scale. There was no upward trend of vehicle collisions with wolves over the study period, possibly reflecting stable wolf populations. Natural mortality due to predation could be promoted through the protection of apex predators, but the lethal management of apex predators, often based on sociopolitical pressures rather than damage levels, can conflict with the strategy for mitigating ungulate impacts. Ungulate management needs to be reconsidered from an ecological perspective that integrates human management measures, including recreational hunting, based on the population dynamics and the recovery of predator–prey interactions by favoring the expansion of apex predators.

Camera-trapping-based social network analysis (SNA) is a valuable tool to characterize communities and identify species with an outstanding role in pathogen maintenance. This study provides new insights into the contentious debate on the effect of biodiversity on disease risk by combining SNA with the assessment of host diversity indicators and pathogen richness in Spain. The apparent species richness detected by camera traps at each study site ranged from 10 to 33 species (mean ± standard error (SE): 20.73 ± 1.94) and their apparent diversity rates (i.e., Shannon index) ranged from 0.57 to 2.55 (mean ± SE: 1.97 ± 0.16). At the community level, vertebrate host diversity had a marginal dilution effect on the disease risk and was negatively correlated to pathogen richness. The exposure to multiple pathogens, as a proxy of disease risk, was negatively associated with apparent host diversity. The disease risk was driven by the interaction of apparent biodiversity with the presence of livestock and with the centrality of the indicator species (i.e., the wild boar). The maximum risk of co-exposure to pathogens was reached when the lowest apparent biodiversity rates coincided with the highest wild boar centrality in the host community or with the presence of livestock, respectively. The highest confluence of pathogens occurred at lower apparent diversity indexes, higher wild boar relative abundances and predominance of agricultural lands. Our results suggest that the diversity-disease relationship is not linear and depends on the environment and host community characteristics, thereby opening avenues for designing new prevention strategies.

Most studies which deal with natural populations require a reliable and convenient way of age estimation. However, even rough aging of live individuals is often a real challenge. In this study, we develop a radiographic method for age estimation in Ellobius talpinus, a promising model species for population and behavioral ecology. Using portable X-ray equipment, we radiographed wild, non-sedated animals from the population that had been subjected to extensive mark-recaptures for 3 years. Two molar metrics strongly dependent on age and easy to measure on radiographs were selected: the lengths of the synclinal folds of the 1st upper and 1st lower molars. No influence of sex on the molar condition age dynamics was found. Discriminant function analysis based on molar condition and date of radiography in 86 animals of known age classes assigned X-ray images to three age classes (young of the year, yearlings, and 2 years or older) with an accuracy of 99%. Leave-one-out cross-validation yielded 97% correct assignments. All age estimates for 52 repeatedly radiographed individuals were consistent across images. The analysis of the repeated X-ray images obtained from the same animals showed that the 1st lower molars change faster in the first summer of life than later whereas the change rate of the 1st upper molars decreases little throughout life. We propose the X-ray technique as a useful alternative to direct skull and dental morphometry for age estimation of wild small mammals, saving the investigator’s time and lives of animals.

The increasing frequency of wildlife-vehicle collisions (WVCs) is a globally recognized problem that can severely impact both the animals and humans involved in these accidents. Introduced wild pigs (Sus scrofa) have been present in various parts of the USA for centuries, but no study on wild pig-vehicle collisions (WPVCs) has been conducted on a national scale for the USA Using data provided by State Farm, we derived the number of vehicle collisions with wild pigs by state in the USA over the 2015–2022 period and the associated vehicle damage costs. In 2022, we estimated that a total of 16,714 wild pig-vehicle collisions occurred, which necessitated $103.8 million in vehicle repair costs. Texas bore the highest burden ($56.2 million), followed by Florida ($12.4 million). We showed that the ratio of collisions with wild pigs to vehicle miles traveled increased with state-level wild pig density and that this ratio is more than seven times higher in Hawaii and Texas than could be expected based solely on the local wild pig densities. Compared to other WVCs, only 1.64% of these accidents were caused by WPVCs. Nationally, WPVCs caused 0.18% of the annual attrition in wild pig populations. WPVCs impose a substantial financial burden to the USA that is unlikely to decrease in the immediate future. WPVC risks are driven by state-specific effects indicating the presence of strong influencing factors at the individual state level. It is thus imperative that transportation and wildlife managers adequately study the issue and collect the data required for mitigation.

Squirrels traded for pets or consumption have the potential to be vectors for zoonotic disease transmission and to establish themselves as invasive species. Callosciurus spp. (Greek for beautiful squirrel) are popular in the pet trade due to their medium size and many colour variants, though several feral populations have established themselves in various parts of the world and these wild-caught individuals can carry and spread infectious diseases. Here, we investigate the live trade in Prevost’s squirrels (C. prevosti) in Indonesia where they are naturally found on the islands of Sumatra, Bangka and Borneo. Between 2016 and 2024, we recorded 284 Prevost’s squirrels for sale, viz., 115 in the physical markets and 169 online. We detected the species for sale in Sumatra (13 individuals), Bangka (7) and Borneo (3), i.e. within their natural range, but also on Java (242) and Bali (4). The mean asking price per individual was US$63, and younger individuals commanded higher prices than older ones. Asking prices were not higher in cities further away from the species’ native range nor in cities with higher purchasing power. All individuals were wild-caught, and with a domestic quota of five individuals allowed to be traded as pets per year (45 over the study period) most of this trade is illegal under Indonesian law. This is distinctly different from trade in Prevost’s squirrels in for instance Europe or the USA where legally captive-bred individuals are offered for sale. In Indonesia the illegal trade happens in the open and despite the risk of the spread of zoonotic diseases wherever it is traded there appears to be little incentive on the side of the authorities to curb this trade. Their widespread availability on Java and Bali risks the accidental or deliberate introduction on these two islands. Better coordination is needed between the Indonesian authorities, online sales sites, pet traders and consumers to stop the sale of illegally obtained Prevost’s squirrels to limit the risk of them becoming invasive species or contributing to the spread of emerging infectious diseases.

Comparative landscape genetics studies provide insights on the impact of landscape elements on gene flow patterns of different species inhabiting the same geographic area. We investigated the population genetic structure of two sympatric ungulates, roe deer Capreolus capreolus and Northern chamois Rupicapra rupicapra, in a mountain area of the central Italian Alps (Trentino, northern Italy). A total of 122 chamois and 72 roe deer samples were genotyped by two species-specific panels of 11 polymorphic microsatellite loci and analyzed by aspatial and spatially explicit analyses. While the roe deer population resulted unstructured, a clear population structure was detected in chamois, with two main groups, one inhabiting the eastern and the other spread in the western part of the study area. Landscape genetics analysis confirmed these scenarios and revealed a different effect of landscape on gene flow. An IBD (Isolation-By-Distance) model best explained genetic variation in roe deer, while IBR (Isolation-By-Resistance) was found as the process underlying genetic variation patterns in chamois, suggesting arable lands, coniferous forests, watercourses, and main roads as potential barriers. Species distribution and landscape use might explain these results: roe deer mostly occupy valley floors relatively connected to each other, and their spatial behavior may promote gene flow across areas. On the other hand, chamois prefer higher elevations and their movements may be hindered by valleys, rivers, and road networks. This study highlights the different impacts of natural and anthropic landscape elements on gene flow in two sympatric species, resulting from their different ecological requirements.

Mast seeding drives large-scale population fluctuations in forest-dwelling animals, including the wild boar Sus scrofa. Many studies of the masting effects on population dynamics of wild boars have been conducted in cool- and warm-temperate forests; however, studies on wild boar populations inhabiting subtropical forests, which have more diverse plant resources than temperate forests, are limited. The mast seeding effects of Castanopsis sieboldii on the reproductive schedule and population fluctuations of wild boars inhabiting the subtropical climate zone of the Ryukyu Islands (Japan) were investigated using 14 years of camera trap data. The reproductive schedule, estimated based on the emergence of piglets, varied in response to masting. The piglet emergence during the January–February period was higher in the years after masting than in the years that followed non-masting events, evidencing that the reproductive season started earlier and lasted longer in the years after masting. The Bayesian state-space model incorporating direct density-dependence and masting effects revealed that the relative population size was negatively affected by the population size of the previous year and positively affected by the previous year’s occurrence of masting. These observations indicate that masting is a critical factor driving population dynamics of wild boars living in subtropical forests and also highlight the importance of mast seeding effects on population fluctuations of wild boars when developing management plans for these animals.

Marking free-living wild mammals may be desirable during field studies and management interventions; however, doing so presents practical challenges. In the context of disease management interventions, different approaches such as vaccination and culling may be deployed in adjacent areas resulting in a need to identify previously vaccinated individuals to avoid losses of vaccination benefits. Badgers (Meles meles) have been identified as a wildlife reservoir of bovine tuberculosis in several countries. In England, the primary means of controlling disease in badger populations has been culling, although policy also includes the use of badger vaccination. Vaccination and culling can therefore increasingly take place in adjacent areas. The current means of marking vaccinated badgers is to apply a fur clip; however, the performance of this method has not been assessed. In this study, we assessed the field performance of livestock markers not previously trialled on badgers. We also assessed the performance of fur clips in terms of (a) how likely they are to be detected on recapture and (b) their detectability using remote cameras. None of the livestock markers trialled persisted well on badger fur. Detectability of fur clips on re-captured badgers fell to 50% in adult badgers by approximately 3 months from application. In cubs, detectability fell to less than 50% within 3 weeks of application. We suggest it is highly likely that, if vaccination and culling were carried out in adjacent areas and fur clipping was the primary means of determining vaccination status, a proportion of recently vaccinated badgers would be removed, particularly cubs. This has important implications for disease control, and we suggest options for minimising such losses.

Abstract

Mountainous regions are very vulnerable to climate changes, as they experience higher temperature increases than the surrounding environments. A general movement of species toward higher altitudes, in search of suitable sites, is being observed. In the case of the Italian Alps, an expansion of the brown hare (Lepus europaeus) is possible within the zones occupied by the mountain hare (Lepus timidus), which frequents higher altitudes. The risk is an increase in the hybridization and a contraction of the mountain hare’s range. In this study, we analyzed the hunting bags (weighted by the number of active hunters each year) of brown and mountain hares from the period of 1980–2020, in the province of Sondrio (Central Alps) in northern Lombardy (N-Italy), with the aim of (i) highlighting any population trends in relation to climate change, (ii) identifying altitudinal changes in the distribution of the two species over the years, (iii) identifying the environmental variables that influence the distribution of the two species, and (iv) creating suitability maps in the study area. To study population trends, the hunting bag data were corrected by dividing the number of hare shot by the number of active hunters in that year. For both species, no population trends were found between 1980 and 2020. Weather variables do not seem to have influenced population trends. No significant trends in the altitudinal distribution of the two species were observed over the period investigated. The results indicate that the two species select different altitudes, with the exception of the belt between 1600 and 1800 m a.s.l. Both species select meadows.

Emotional responses to wildlife can guide human responses to wildlife conflicts. At the same time, responses to wildlife often relate to cultural contexts. In this study, emotions associated with wolves and wild boars were examined in two samples taken from Turkish (N = 637) and German (N = 415) university students. As expected, different patterns of emotional responses emerged in the two samples. For example, while negative emotions such as disgust and anger toward the wild boar were prevalent in the Turkish sample, positive emotions such as joy, surprise, and interest occurred in the German sample. Significant differences between the emotions associated with wolves and wild boars were revealed in both samples. In the Turkish sample, wolves caused stronger fear, joy, and interest, whereas wild boars caused stronger anger and disgust. In the German sample, wolves caused stronger joy, surprise, interest, and sadness, whereas wild boars caused stronger disgust. Fear, however, was expressed toward both wolves and wild boars in both samples. The predictive power of emotions on students’ intentions to protect wild boars and wolves was examined as well as intentions to protect human interests against these animals. Disgust was the strongest (negative) predictor of a protection intention toward the wild boar in the Turkish sample. In the German sample, joy and interest were the emotions that best predicted conservation intentions (positive) for both animals.