European Journal of Wildlife Research最新文献

The very large demand for songbirds in Indonesia undermines the efforts of the Government of Indonesia to regulate and control harvest and trade. As more species become increasingly rare, new species are sought after and included in the trade to supply demand from hobbyists, traders and songbird competition participants. One such group of species is the butcherbirds. Four species of butcherbirds are native to Indonesia and prior to 2016 these birds were hardly found in trade. Since then, the trade has grown rapidly and during 57 surveys of bird markets in 12 cities on Java, Bali and Lombok, we recorded 235 butcherbirds. We found 43 advertisements online offering butcherbirds for sale. The highest numbers were recorded in the easternmost cities we surveyed (Mataram, 11.5 birds/survey; Denpasar 9.0 birds/survey) and we recorded higher numbers of butcherbirds for sale nearer to their natural distribution range. Compared to other species, butcherbirds command high prices (hooded butcherbird: US$185; black butcherbird: US$122). Despite the authorities attempting to regulate the exploitation of butcherbirds with annual harvest and trade quotas (set at zero for 2022), the trade evidently is challenging to control and may pose a threat to the conservation of these species in the wild.

Populations of large herbivores can be efficiently managed by regulating the number of females, which is directly related to recruitment. This study aims to determine seasonal changes in the attractiveness of salt water to female Sika deer (Cervus nippon) in order to cull females more efficiently. Females drank saltwater well at similar times of the year for saltwater with different installation dates. In particular, the frequency of drinking increased from early April to mid-July. Previous studies have shown that salt water is an effective attractant for capturing females, but the results of this study suggest that females may be captured more effectively in spring and early summer. This is the birthing season for sika deer. Culling females in late pregnancy and lactation may also directly reduce recruitment due to higher mortality of young. Saltwater-induced culling of female sika deer may be an effective method of managing overpopulation of the deer.

Identification and assessment of habitat suitability are essential to the conservation of threatened species such as the Asiatic black bear (Ursus thibetanus) in Pakistan. Regionally, for example, in the Hindu Kush Mountains, there has been growing public concern regarding negative impacts on the bears’ natural habitats due to land use and climate change. Many of the efforts to identify and conserve suitable habitats are based on limited data and have been unable to accurately predict habitat preferences. This study aims to fill this gap by developing predictive models for U. thibetanus based on the integration of new occurrences and climate and land cover data. We installed camera traps in 81 different locations across a gradient of elevation. Over the duration of 413 trap nights, we collected 110 different bear detections at 31 camera stations. The bear favored densely forested regions between 1,835 m and 3,348 m above sea level, with a catch rate of 26.6/100 trap nights. Our models demonstrated high levels of prediction accuracy (AUC > 0.97) and predicted that 43% of the total area would make a good habitat for bears. The mean temperature of coldest quarter, normalized difference vegetation index, and annual mean temperature were the main determinants of habitat suitability. The findings of this study, which is the first to map the current distribution and suitable habitat of the Asiatic black bear in the Hindu Kush Mountain Range, contribute new local-scale habitat suitability data to the study of bears in Swat Valley, Pakistan. Our results may be used to provide important conservation information for U. thibetanus that is useful to policymakers for improving future management planning.

The pond slider (Trachemys scripta) is a major invasive species in freshwater habitats across the world. For decades, the main cause of individuals’ occurrences in the wild was the illegal release of pet animals. Recently, as an important component of their management, there has been an increasing focus on their ability to successfully reproduce in the invaded regions. In Romania, the species is reported as widespread in urban wetland environments within major cities, but information about its nesting and potential breeding remains scarce or anecdotal. We surveyed a large population of pond sliders in an artificial urban wetland site in Constanţa, SE Romania, and described their nesting ecology and reproductive output. Although eggs from several nests failed to hatch or were predated, potentially limiting their reproductive success, sliders were found to breed successfully at this site, with 18.6% viable hatchlings recorded. Our study could serve as a baseline for additional targeted surveys and to inform decision-making for successfully managing this invasive species. Although the importation, trading, and breeding of this species are prohibited by EU legislation, active and effective management is now required to address the successful reproduction and further potential spread of T. scripta.

Infestation by the sheep bot fly Oestrus ovis was firstly reported in a single roe deer from Central Spain in 2022. For assessing the current situation of nasal myiases in this ungulate in this area, the nasopharyngeal cavities of 184 roe deer hunted in Central Spain between January-June 2023 were examined. All larvae were recovered and morphologically identified; in addition, species identification was molecularly confirmed in a subset of specimens. Forty-four roe deer (23.9%; CI 95 17.95–30.74) were positive for different Oestrinae larval stages. Twenty-six animals (14.1%; CI 95 9.44–20.02%) were infested by the roe deer nasal bot fly (Cephenemyia stimulator) with a mean intensity of 35.2 (SD 49.71) larvae/infested animal, and eighteen (9.8%; CI 95 5.90-15.02%) roe deer harboured the sheep bot fly (O. ovis), with a mean intensity of 2.0 (SD 1.33) larvae/infested animal. No mixed infestations by both Oestrinae were found in a single animal. All larval instars (L1, L2 and L3) of both species were identified. Most C. stimulator specimens were located at the nasal turbinates, and a small percentage (3.2%) at the pharynx; all O. ovis larvae were found at the nasal turbinates. Since O. ovis is highly prevalent in sheep and goat flocks from Central Spain, the high sympatry between roe deer and small ruminant populations in the studied area may have increased the risk of cross-infection. Moreover, the finding of mature L3 of O. ovis suggests that this species can complete its life cycle in roe deer. Therefore, monitoring bot flies in sheep and goat flocks as well as in sympatric wild ruminants is strongly recommended for achieving an optimum control of nasal myiases.

Thyroid hormones play a role in the control of seasonal reproduction in wild and domestic ruminants such as red deer and sheep. Horn growth shows an inverse relationship with reproductive activity, but the effect of thyroid function on the regulation of the seasonal pattern of horn growth is unknown. This work examines the seasonal pattern of plasma thyroxine concentration, and its effect on testosterone secretion and seasonal changes in horn growth, in male Iberian ibexes (Capra pyrenaica). Plasma testosterone, plasma thyroxine, and horn growth were measured over a year in four males kept under natural photoperiod conditions. In another four, thyroxine was administered coinciding with the period of physiological reduction in plasma testosterone (January–February). In the first four, seasonal changes in the plasma concentration of thyroxine were detected with the highest concentrations recorded in October, November, and December, coinciding with the greatest testosterone secretion. In the second four, thyroxine treatment affected neither plasma testosterone concentration nor horn growth. The plasma concentrations of testosterone and thyroxine appear to be closely related in the ibex, but the seasonal pattern of horn growth does not seem to be modulated by seasonal changes in thyroxine.

Harmonising methodology between countries is crucial in transborder population monitoring. However, immediate application of alleged, established DNA-based methods across the extended area can entail drawbacks and may lead to biases. Therefore, genetic methods need to be tested across the whole area before being deployed. Around 4,500 brown bears (Ursus arctos) live in Norway, Sweden, and Finland and they are divided into the western (Scandinavian) and eastern (Karelian) population. Both populations have recovered and are connected via asymmetric migration. DNA-based population monitoring in Norway and Sweden uses the same set of genetic markers. With Finland aiming to implement monitoring, we tested the available SNP-panel developed to assess brown bears in Norway and Sweden, on tissue samples from a representative set of 93 legally harvested individuals from Finland. The aim was to test for ascertainment bias and evaluate its suitability for DNA-based transnational-monitoring covering all three countries. We compared results to the performance of microsatellite genotypes of the same individuals in Finland and against SNP-genotypes from individuals sampled in Sweden (N = 95) and Norway (N = 27). In Finland, a higher resolution for individual identification was obtained for SNPs (PI = 1.18E-27) compared to microsatellites (PI = 4.2E-11). Compared to Norway and Sweden, probability of identity of the SNP-panel was slightly higher and expected heterozygosity lower in Finland indicating ascertainment bias. Yet, our evaluation show that the available SNP-panel outperforms the microsatellite panel currently applied in Norway and Sweden. The SNP-panel represents a powerful tool that could aid improving transnational DNA-based monitoring of brown bears across these three countries.

In the European Union, African swine fever (ASF) affects wild boar (Sus scrofa) populations in several Member States. Knowledge of population connectivity is important for the implementation of control measures, in particular the establishment of effective barriers. Population genetic comparisons of neighbouring populations can be very helpful in this respect. The present study investigated the genetic differentiation of wild boar in eastern Germany. This region has been affected by ASF since September 2020. A total of 1,262 wild boars from 31 hunting grounds (populations) in ASF-affected and ASF-free districts were sampled over a total area of almost 100,000 km². The study area encompassed a network of geographical factors that promote (roads, rivers, cities) or inhibit (natural areas, habitat corridors) genetic differentiation between wild boar populations. The genetic differentiation of the areas was based on 12 microsatellite markers. Three different Bayesian algorithms were used to analyse the data. The results were combined into a common approach with 9 clusters. Based on the cluster distribution in each population, the connectivity between the areas was quantified. The strongest differentiation was found along an imaginary line along the lower Elbe valley through Berlin and the A11 freeway to the Szczecin Lagoon. In contrast, the Mecklenburg Lake District and the south-east of the study area showed strong connectivity between areas. The special features of the landscapes along the lower Elbe valley, which was assessed as highly connective, and the high barrier effect of the A11 freeway in contrast to the other freeways in the study area show that barrier effects cannot be generalised in principle, but are actually determined by the circumstances of individual structures. The results of the connectivity analysis were compared with the distribution of viral lineages and variants. The genotypes of the wild boar populations and the ASFV lineages and variants showed a good explanatory approach for the observed disease dynamics in the study area. The newly gained knowledge on barriers and regionally different connectivity between wild boar populations can support considerations and measures for the containment of ASF in the affected areas by improving the understanding of wild boar dispersal dynamics.

An increasing number of GPS telemetry studies have helped to gain important insights into predator-prey relationships in recent years. However, considerable time and effort is needed to evaluate whether GPS location clusters (GLCs) reflect predation events. To reduce field effort, predictive models are being developed to calculate predator kill intervals, but few studies have attempted to do this for a specific species of prey. Between 2013 and 2018, we studied predation by 13 GPS-collared Eurasian lynx (Lynx lynx) on Alpine chamois (Rupicapra rupicapra) in the northwestern Swiss Alps. Our objectives were to predict the total number of killed chamois, including potential kills in unchecked GLCs, and to evaluate if model predictions were sufficiently accurate. We built a set of generalized linear models (GLM) predicting the occurrence of GLCs containing lynx-killed chamois (1) versus GLCs containing other prey types or no prey (0) and compared their predictive performance by means of k-fold cross-validation. We found that model performance was very similar for all candidate models, with the full model yielding the best cross-validation result (accuracy = 0.83, sensitivity = 0.43, specificity = 0.94). Female lynx killed on average one chamois every 11.9 days (10.6–13.0 days, 95% CI); male lynx killed one chamois every 7.2 days (6.7–7.6 days, 95% CI). Our model showed high specificity for detecting non-chamois GLCs, but sensitivity for detection of GLCs with actual chamois kills was low. We conclude that the sensitivity of the models should be further improved, but the results can be sufficient for practical application. Predictive modelling approaches do not replace extensive fieldwork but require large sets of field data, high individual variability and thorough knowledge of a predator’s ecology and prey community. Our approach may provide useful results for binary classifications in rather simple predator-prey systems, but extrapolations from one study system to another might be difficult.

The U Minh wetlands of southern Vietnam in Ca Mau and Kieng Giang provinces are a degraded, peat-swamp wetland mosaic known to retain several globally threatened species. We deployed 83 targeted camera-traps across U Minh Thuong National Park and U Minh Ha National Park from December 2019 to May 2020, and from November 2020 to June 2021, respectively. Our aim was to detect threatened otters, wild cats, and pangolins in each protected area, to identify relative abundance, activity patterns, and what potential threats they may face to inform conservation priorities for park managers. Our results showed that both protected areas harbour significant regionally important populations of globally threatened Sunda pangolins (Manis javanica), and Hairy-nosed otters (Lutra sumatrana). However, Fishing cats (Prionailurus viverrinus) and Large-spotted civet (Viverra megaspila) previously recorded from U Minh Thuong National Park, were not observed, emphasising the probability of local extirpation. Other than wide-ranging species that are less sensitive to human disturbance (i.e., Common palm civets and Leopard cats), all small carnivores were most active in Melaleuca and swamp/Melaleuca habitats in U Minh Thuong, and both the wetland plantations and disturbed forests of U Minh Ha according to their photographic rates. Human and domestic dogs’ activity periods in both protected areas overlapped strongly with Hairy-nosed otters, which could influence their dispersal abilities and access to resources. Long-term and short-term threats are discussed with relevance to U Minh ecosystem health and future recommendations.