Niche partitioning between sympatric wild canids: the case of the golden jackal (Canis aureus) and the red fox (Vulpes vulpes) in north-eastern Italy

Dietary Differentiation Mitigates Interspecific Interference Competition Between Sympatric Pallas's Cats (Otocolobus manul) and Red Foxes (Vulpes vulpes)

The comparative analysis of the feeding ecology among sympatric small carnivores reveals both differentiation and overlap in resource utilization patterns, which serves as a critical pathway for understanding interspecific interactions and maintaining ecosystem stability. In this study, we collected fecal samples from sympatric Pallas's cats (Otocolobus manul, n = 26) and red foxes (Vulpes vulpes, n = 13) within the Sanjiangyuan National Park (SNP) in China. Subsequently, DNA barcoding technology was employed to analyze the dietary composition and interspecific differences of these two small carnivores. The results demonstrated that both species primarily prey on plateau pikas (Ochotona curzoniae) and small rodents. Despite a high trophic niche overlap between Pallas's cats and red foxes (Ojk = 0.81), interspecific competition is mitigated through differentiate feeding proportions of shared prey species. Furthermore, the trophic niche breadth of red foxes (B = 267.89) exceeds that of Pallas's cats (B = 162.94), reflecting a greater diversity of prey resources utilized by red foxes. Consequently, the two small carnivores achieve sympatric coexistence via differentiated resource utilization. These findings enhance our understanding of the coexistence mechanisms within carnivore communities and provide a scientific basis for the conservation of wildlife in the SNP.

Acoustic Localisation as a Tool to Aid Monitoring of Golden Jackals (Canis aureus)

Golden jackals (Canis aureus) have rapidly expanded their range across Europe, raising ecological and socioeconomic concerns. As a highly vocal species, jackals can be monitored using howl surveys or passive acoustic monitoring (PAM) to estimate population sizes and habitat preferences. A recent advancement in PAM is acoustic localisation, which estimates the source of sounds by measuring the time differences of their arrival at multiple synchronised recorders. This technique can improve the accuracy of population and density estimates by more precisely calculating distances between vocalising animals and recorders. However, GPS-synchronised acoustic recorders are costly, which limits their broader use. In this study, we tested the efficacy of a low-cost recorder, the CARACAL, for acoustic localisation of golden jackals. We deployed 10 CARACALs over a 10 km2 area of the Lunca Mureşului Natural Park, Romania, for seven nights. Alongside passively recording jackal howls, we also conducted howl surveys. We recorded jackal howls every night of the survey and successfully localised 27 jackal and 16 human howls, with human howls localised to within an average of 41 m of their actual location. The average distance between the recorders and estimated positions of vocalising jackals was just under 1 km, with howls detected from as far as 2.5 km away. However, some jackal howls were not detected clearly, or at all, on active recorders that were as little as 0.9 km away. Based on these results, we recommend a conservative spacing of 0.8-1 km between recorders in future deployments, though this will depend on local environmental conditions. Overall, this study highlights acoustic localisation as a valuable tool for improving monitoring efforts and gathering more detailed data on jackal ecology. This information could significantly contribute to understanding their expanding range across Europe while informing the development of effective monitoring and management strategies for golden jackals.

Retrospective multidisciplinary analysis of human alveolar echinococcosis in Hungary using spatial epidemiology approaches

Human alveolar echinococcosis (HAE), which is caused by the larval stage of the Echinococcus multilocularis tapeworm, is an increasing healthcare issue in Hungary. Among the 40 known cases in the country, 25 were detected in the last five years. Our study aimed to reveal the geographically underlying risk factors associated potentially with these cases. We investigated the spatial pattern and the impact of potential risk factors of HAE by cluster analysis, and local and global regression models. Also, a questionnaire survey on the patients' lifestyle was implemented. We found two HAE hyperendemic foci in the country with very dissimilar biotic and climatic features, and controversial impact of different environmental factors. Four factors, viz. forest cover (β = 0.291, p < 0.0001), surface soil wetness (β = - 0.157, p = 0.033), fox infection rate (β = 0.369, p < 0.0001) and socio-economic development (β = - 0.216, p = 0.009), proved important countrywide. The most forested and the least developed districts showed the highest HAE risk. Among the patients, kitchen gardening (67.86%) and dog ownership (67.86%) seemed the riskiest activities. Our models detected an anomaly in one of the poorest regions of Hungary where all risk factors behaved contrary to that of the neighboring areas. This phenomenon was supposed to be the result of under-detection of the disease, and it called attention to the urgent priority of knowledge dissemination to the public and the healthcare professionals.

Diversity and cross-species transmission of viruses in a remote island ecosystem: implications for wildlife conservation

The ability of viruses to emerge in new species is influenced by aspects of host biology and ecology, with some taxa harbouring a high diversity and abundance of viruses. However, how these factors shape virus diversity at the ecosystem scale is often unclear. To better understand the pattern and determinants of viral diversity within an ecosystem, and to describe the novel avian viruses infecting an individual avian community, we performed a metagenomic snapshot of the virome from the entire avian community on remote Pukenui/Anchor Island in Aotearoa New Zealand. Through total RNA sequencing of 18 bird species, we identified 50 avian viruses from 9 viral families, of which 96% were novel. Of note, passerines (perching birds) exhibited high viral abundance and diversity, with viruses found across all nine viral families identified. We also identified numerous viruses infecting seabirds on the Island, including megriviruses, hepaciviruses, and hepatoviruses, while parrots exhibited an extremely low diversity of avian viruses. Within passerines, closely related astroviruses and hepatoviruses, and multiple identical hepe-like viruses, were shared among host species. Phylogenetic reconciliation analysis of these viral groups revealed a mixture of co-divergence and cross-species transmission, with virus host-jumping relatively frequent among passerines. In contrast, there was no evidence for recent cross-species virus transmission in parrots or seabirds. The novel pegiviruses and a flavivirus identified here also pose intriguing questions regarding their origins, pathogenicity, and potential impact on vertebrate hosts. Overall, these results highlight the importance of understudied remote island ecosystems as refugia for novel viruses, as well as the intricate interplay between host ecology and behaviour in shaping viral communities.

Daily Activity Patterns and Overlap Activity of Medium-Large Mammals in Sülüklü Lake Nature Park, Western Black Sea Region, Türkiye

Türkiye, due to its position as a bridge between Asia and Europe, encompassing three distinct biogeographic regions and its diverse climatic conditions and geographical features, exhibits the characteristics of a small continent in terms of biodiversity, hosting a very high number of mammalian species. However, information on these mammals' activity patterns and co-occurrence, specifically in Türkiye, is limited. Our study aimed to reveal the daily activity patterns and temporal overlaps of mammalian species detected using camera traps in Sülüklü Lake Nature Park. The white-breasted hedgehog was strictly nocturnal, while the European badger, gray wolf, European hare, wild boar, and beech marten tended to be nocturnal. The Caucasian squirrel was strictly diurnal, and the roe deer tended to be diurnal. The highest temporal overlap was found between the white-breasted hedgehog and the beech marten (∆4 = 0.84, 95% CI), followed by the red fox and roe deer (∆1 = 0.77, 95% CI). The lowest temporal overlap (∆1 = 0.081, 95% CI) was found between the white-breasted hedgehog and the Caucasian squirrel. The second lowest overlap (∆1 = 0.136, 95% CI) occurred between the Caucasian squirrel and the European badger. Our findings have provided new and detailed insights into the diversity of mammalian species within the nature park located in Northwestern Anatolia. These data will support and facilitate future research aimed at understanding the mechanisms of species coexistence in this ecosystem. The results obtained will enable a deeper examination of ecosystem dynamics and contribute to developing strategies for biodiversity conservation.

Different coexistence patterns between apex carnivores and mesocarnivores based on temporal, spatial, and dietary niche partitioning analysis in Qilian Mountain National Park, China

Carnivores play key roles in maintaining ecosystem structure and function as well as ecological processes. Understanding how sympatric species coexist in natural ecosystems is a central research topic in community ecology and biodiversity conservation. In this study, we explored intra- and interspecific niche partitioning along spatial, temporal, and dietary niche partitioning between apex carnivores (wolf Canis lupus, snow leopard Panthera uncia, Eurasian lynx Lynx lynx) and mesocarnivores (Pallas's cat Otocolobus manul, red fox Vulpes vulpes, Tibetan fox Vulpes ferrilata) in Qilian Mountain National Park, China, using camera trapping data and DNA metabarcoding sequencing data. Our study showed that apex carnivore species had more overlap temporally (coefficients of interspecific overlap ranging from 0.661 to 0.900) or trophically (Pianka's index ranging from 0.458 to 0.892), mesocarnivore species had high dietary overlap with each other (Pianka's index ranging from 0.945 to 0.997), and apex carnivore and mesocarnivore species had high temporal overlap (coefficients of interspecific overlap ranging from 0.497 to 0.855). Large dietary overlap was observed between wolf and snow leopard (Pianka's index = 0.892) and Pallas's cat and Tibetan fox (Pianka's index = 0.997), suggesting the potential for increased resource competition for these species pairs. We concluded that spatial niche partitioning is likely to key driver in facilitating the coexistence of apex carnivore species, while spatial and temporal niche partitioning likely facilitate the coexistence of mesocarnivore species, and spatial and dietary niche partitioning facilitate the coexistence between apex and mesocarnivore species. Our findings consider partitioning across temporal, spatial, and dietary dimensions while examining diverse coexistence patterns of carnivore species in Qilian Mountain National Park, China. These findings will contribute substantially to current understanding of carnivore guilds and effective conservation management in fragile alpine ecosystems.

Identification and phylogenetic analysis of Taenia spp. parasites found in wildlife in the Emilia-Romagna region, northern Italy (2017-2022)

The recent expansion of the habitat of several wildlife species, comprising anthropized areas, is a relevant risk factor for many zoonotic diseases and should be considered in national and regional sanitary monitoring systems. We evaluated adult intestinal Taenia spp. parasites isolated from wild carnivores and cystic larval forms isolated from wild mammals analysed at the Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia-Romagna (IZSLER) as part of the regional wildlife sanitary surveillance plan. Then, we assessed parasite species through molecular analysis (multiplex PCR followed by ribosomal 12S subunit gene sequencing) in order to update the epidemiological situation on Taeniids infection in the Emilia-Romagna wildlife, reporting the prevalence of each isolated species. The most commonly isolated species was Taenia serialis, which we detected in both wolves and foxes as definitive hosts and in roe deer as intermediate host. More attention on the distribution of Taeniids in wildlife should be paid, considering their potential zoonotic role: several Taenia spp. (Taenia solium, Taenia multiceps, Taenia serialis, Taenia brauni, Taenia glomerulatus) are known for causing coenurosis in humans, with possible severe or fatal outcomes.

Wolf Is Back: A Novel Sensitive Sentinel Rejoins the Trichinella Cycle in the Western Alps

Trichinella is a foodborne parasite whose wildlife reservoirs are represented by carnivores and omnivores with predatory and scavenger behavior. The aim of the present study was to investigate the occurrence of Trichinella infection in grey wolves (Canis lupus) that recolonized the Western Alps from the end of the past century, and discuss the epidemiological role played by this apex predator in the early phases of its return. During the period 2017–2022, diaphragm samples were obtained from 130 individuals collected in the frame of a wolf mortality survey. Trichinella larvae were found in 15 wolves (11.53%) with a parasite intensity of 11.74 larvae per gram. Trichinella britovi was the only species identified. This is the first prevalence survey of Trichinella in wolves recolonizing the Alps. Results suggest that, in this particular biotope, the wolf has rejoined the Trichinella cycle and has the potential to play an increasingly important role as maintenance host. Arguments in favor and against this perspective are discussed and knowledge gaps highlighted. The calculated Trichinella larval biomass in the estimated wolf population roaming in Northwest Italy will serve as baseline value to explore possible shifts in the relative importance of wolves as Trichinella reservoir within the regional carnivore community. Finally, wolves re-colonizing the Alps already appear as sensitive sentinels to monitor the risk of Trichinella zoonotic transmission by infected wild boar meat.

Is resource partitioning between two sympatric species of Gracilinanus (Didelphimorphia: Didelphidae) related to trophic and spatial niches?

Small mammal species may occur in sympatry, and it is relevant to investigate the mechanisms that lead to coexistence of the closely related species. Despite this, studies evaluating the coexistence of closely related Neotropical marsupials are insipient. The aim of this study was to analyse the mechanisms of resource partitioning between the sympatric species of mouse opossums Gracilinanus agilis and G. microtarsus (Didelphidae), evaluating their trophic and spatial niche. We hypothesized that G. agilis and G. microtarsus differ in at least one niche dimension (space use or food preferences) as a mechanism of coexistence. In the study we analysed trophic niche by evaluating the frequency of occurrence of food items present in Gracilinanus faeces. Also, we analysed spatial niche by comparing the vegetal stratum where the individuals were captured and its relationship with the environmental complexity. Both species presented a high trophic niche overlap, with differences in the frequencies of occurrence of the consumed items. Although the most frequent items in the faeces were Hymenoptera, Isoptera and Coleoptera, their proportion differed significantly between the two species. The variety of food items also differed, with flowers being more frequent in G. agilis diet, whereas fruits were more recorded for G. microtarsus. The spatial niche was very similar, with both species being more captured in the forest understory. However, habitat complexity influenced the abundance of both species, especially litter depth and its biomass of leaves. The results indicated that the coexistence of the two species is associated with the trophic and spatial niche, and that this niche segregation could be allowing closely related species of Gracilinanus to coexist.

From the Balkan towards Western Europe: Range expansion of the golden jackal (Canis aureus)-A climatic niche modeling approach

In recent decades, a rapid range expansion of the golden jackal (Canis aureus) towards Northern and Western Europe has been observed. The golden jackal is a medium-sized canid, with a broad and flexible diet. Almost 200 different parasite species have been reported worldwide from C. aureus, including many parasites that are shared with dogs and cats and parasite species of public health concern. As parasites may follow the range shifts of their host, the range expansion of the golden jackal could be accompanied by changes in the parasite fauna in the new ecosystems. In the new distribution area, the golden jackal could affect ecosystem equilibrium, e.g., through changed competition situations or predation pressure. In a niche modeling approach, we project the future climatic habitat suitability of the golden jackal in Europe in the context of whether climatic changes promote range expansion. We use an ensemble forecast based on six presence-absence algorithms to estimate the climatic suitability of C. aureus for different time periods up to the year 2100 considering different IPCC scenarios on future development. As predictor variables, we used six bioclimatic variables provided by worldclim. Our results clearly indicate that areas with climatic conditions analogous to those of the current core distribution area of the golden jackal in Europe will strongly expand towards the north and the west in future decades. Thus, the observed range expansion may be favored by climate change. The occurrence of stable populations can be expected in Central Europe. With regard to biodiversity and public health concerns, the population and range dynamics of the golden jackal should be surveyed. Correlative niche models provide a useful and frequently applied tool for this purpose. The results can help to make monitoring more efficient by identifying areas with suitable habitat and thus a higher probability of occurrence.