Human induced translocation and introduction of species have reshaped parasite fauna on a global scale. The introduction of the large American liver fluke Fascioloides magna from North America to ...Europe is an example of an invasive alien parasite causing significant ecological and economic damage. Recent genetic studies have shown that F. magna was introduced to Europe on multiple occasions forming three permanent foci of infection. This study primarily focuses on the poorly researched genetic structuring of F. magna flukes originating from Croatia and Serbia. Additional samples from USA and Italy are also included, thereby providing novel insights into F. magna’s biogeography. Partial cox1 and nad1 genes were amplified from 216 F. magna flukes extracted from red deer, roe deer, fallow deer, white-tailed deer and wild boar. Seven cox1 and nine nad1 haplotypes were identified, of which two cox1 and four nad1 haplotypes have not been not previously found. Our analysis has expanded the knowledge about possible sources of F. magna introduction to Europe, by identifying a cox1 haplotype shared by flukes from the north-eastern parts of the USA and Italy and another cox1 haplotype shared by flukes also from north eastern parts of the USA and the Danube floodplains.
•New cox1 and nad1 haplotypes identified in Fascioloides magna from Serbia, Italy and USA.•Additional confirmation that F. magna was introduced to Europe at least twice.•Western North America was not the only source of F. magna introduction to Italy- New York state is a possible source of F. magna introduction to Europe.
Rehabilitation of injured or immature individuals has become an increasingly used conservation and management tool. However, scientific evaluation of rehabilitations is rare, raising concern about ...post-release welfare as well as the cost-effectiveness of spending scarce financial resources. Over the past 20 years, events of juvenile Eurasian lynx presumably orphaned have been observed in many European lynx populations. To guide the management of orphaned lynx, we documented survival, rehabilitation and fate after the release and evaluated the potential relevance of lynx orphan rehabilitation for population management and conservation implications. Data on 320 orphaned lynx was collected from 1975 to 2022 from 13 countries and nine populations. The majority of orphaned lynx (55%) were taken to rehabilitation centres or other enclosures. A total of 66 orphans were released back to nature. The portion of rehabilitated lynx who survived at least one year after release was 0.66. Release location was the best predictor for their survival. Of the 66 released lynx, ten have reproduced at least once (8 females and 2 males). Conservation implications of rehabilitation programmes include managing genetic diversity in small, isolated populations and reintroducing species to historical habitats. The lynx is a perfect model species as most reintroduced populations in Central Europe show significantly lower observed heterozygosity than most of the autochthonous populations, indicating that reintroduction bottlenecks, isolation and post-release management have long-term consequences on the genetic composition of populations. The release of translocated orphans could be a valuable contribution to Eurasian lynx conservation in Europe. It is recommended to release orphans at the distribution edge or in the frame of reintroduction projects instead of a release in the core area of a population where it is not necessary from a demographic and genetic point of view. Rehabilitation programmes can have conservation implications that extend far beyond individual welfare benefits.
Reintroductions may produce populations that suffer from decreasing genetic diversity due to isolation, genetic drift and inbreeding if not assisted by careful management. To assess the genetic ...outcomes of reintroductions in large carnivores, we used the Eurasian lynx (Lynx lynx) as a case study, which was the subject of several reintroduction attempts over the last 50 years. Although some restocking actions initially appeared successful, lynx recovery has stagnated in recent years. To reveal potential genetic causes of slow lynx recovery in Europe, we examined genome-wide patterns of genetic diversity and inbreeding using single nucleotide polymorphisms (SNPs) in all six successfully reintroduced populations in central Europe, as well as twelve natural populations across Europe and Asia. All reintroduced populations showed lower genetic diversity and elevated levels of inbreeding compared to source and other natural populations. Recent inbreeding is prevalent in all reintroduced populations with varying degrees of severity; the most severe cases are those with the lowest number of founding individuals. Interestingly, we found evidence of lower genetic diversity and recent inbreeding in the source population for five reintroduced populations, begging the question if individuals taken from these source populations can safeguard sufficient genetic diversity for future reintroductions. Given the observed genetic consequences, we advocate for standardized regular genomic assessment of source and target populations as well as individuals prior to release. Our study provides compelling evidence for the serious consequences of founder population size on the genetic diversity of reintroduced large carnivore populations, which has broad implications for their conservation.
•A high number of genetically tested founders in large mammal reintroduction programs are essential.•Reintroduced Eurasian lynx populations across Central Europe exhibit genome wide diversity loss.•Several reintroduced populations suffer from considerable recent inbreeding (ROH analysis).•Urgent natural or human-mediated reconnection of reintroduced populations is essential.
Quantification of animal phenotypic traits could allow objective description of individuals and their morphology, reducing bias caused by human subjectivity, skill and experience. The goal of our ...study was to research a quantitative approach to analyzing the four types of coat patterns recognized in endangered Eurasian lynx (Lynx lynx) in Croatia and to track frequencies of coat patterns over time. A total of 195 photographs of lynx individuals from Croatia, collected in the 1978–2019 period, were visually assigned to one of four types of coat patterns: no spots, small spots, big spots, and rosettes. Then, using metrics available within the public-domain software ImageJ, we quantified lynx spot traits and compared the characteristics of the four coat patterns to detect objective differences. All metrics that were analyzed differed significantly between “no spots” and other coat patterns (p < 0.05), whereas none of the metrics differed significantly between coats of small spots and coats of rosettes. Luckily, researchers visually distinguished easily coats of rosettes from coats of small spots. In contrast, when coats of big spots were numerically compared to those of small spots, they differed significantly in spot size on the whole body, while in some lynx individuals these two patterns proved to be most difficult for researchers to distinguish by eye. When looking at the occurrence of the four coat patterns inside the two temporal categories, they differed significantly between individuals photographed in 1978–1999 and those photographed in 2001–2019. The frequency of coats without spots fell from 14% to zero, the frequency of rosettes dropped from 23% to 9%, while the frequency of big spots increased from 46% to 80%. Significant inbreeding and low population size were genetically proven in Croatian lynx population, but to link inbreeding with the phenotypic change we observed, further research should be conducted.
Estimating abundance of wild animal populations is crucial for their management and conservation. While spatial capture-recapture models are becoming increasingly common to assess the densities of ...elusive species, recent studies have indicated potential bias that can be introduced by unaccounted spatial variation of detectability. We used camera-trapping data collected in collaboration with local hunters from a transnational population survey of the Eurasian lynx (
Lynx lynx
) in Slovenia and Croatia, to provide the first density estimate for the threatened Eurasian lynx population in the Northern Dinaric Mountains. Population density was 0.83 (95% CI: 0.60–1.16) lynx/100 km
2
, which is comparable to other reintroduced Eurasian lynx populations in Europe. Furthermore, we showed that baseline detection rate was influenced by the type of site used, as well as by sex of the individual and local behavioural response. Scent-marking sites had on average a 1.6- and 2.5-times higher baseline detection rate compared to roads and other locations, respectively. Scent-marking behaviour is common for several mammals, and selecting sites that attracts the targeted species is used to increase detection rates, especially for rare and cryptic species. But we show that the use of different location types for camera trapping can bias density estimates if not homogenously distributed across the surveyed area. This highlights the importance of incorporating not only individual characteristics (e.g., sex), but also information on the type of site used in camera trapping surveys into estimates of population densities.
The daily activity patterns of animals are modulated by external factors such as habitat selection, temporal niche selection, prey availability and predation risk. Furthermore, different species show ...a variety of responses to human disturbance; therefore, to understand the effects of human activities on wildlife, it is crucial to consider the disturbance characteristics (e.g. type, frequency, timing and location of human activity). Our objective was to evaluate whether vehicles on forest roads altered the daily temporal activity patterns of three apex predators; Eurasian lynx (Lynx lynx), the grey wolf (Canis lupus) and brown bear (Ursus arctos), using an extensive camera trap data set collected across a gradient of forest roads and wildlife trails in the Croatian part of the Dinaric mountains. We expected a low temporal overlap between humans and apex predators but predicted this even lower at sites where vehicles are present. Consistent with our expectations, the general overlap in temporal activity of all three apex predators and humans was low, the former being primarily active at night/dawn/dusk hours and the latter during daylight hours. In contrast, our results showed similarity in the temporal activity of all three predators on wildlife trails and forest roads where human activity was more frequent and diverse.
During the early 1900s, Northern chamois (
Rupicapra rupicapra
) populations in the northern Dinaric Mountains were extirpated. During the 1960s and 1970s there were several reintroductions of ...individuals from two Northern chamois subspecies (Alpine chamois,
R. r. rupicapra
and Balkan chamois,
R. r. balcanica
) from neighbouring areas in the attempt to re-establish the population. Accurate taxonomic classification, at subspecies level, of the autochthonous extirpated population was not known. To clarify which subspecies was present before reintroduction, we genotyped four male chamois skulls originating from Velebit Mountain, collected around 25 years before the population local extinction. DNA was successfully extracted from middle layer and outer sheath of horns. Assignment based on microsatellite loci, using both Bayesian clustering in STRUCTURE (with q values between 0.55 and 0.73) and DAPC (with individual membership probabilities of 0.99 and 1.00) indicated higher assessed likelihood for the Alpine subspecies.
Tapeworms of the genus
Mesocestoides
(Cestoda: Cyclophyllidea: Mesocestoididae) are still enigmatic to scientists, due to their high morphological variability, low host specificity, and unknown ...details of their life cycle. They are found worldwide, with carnivorous mammals as the main definitive hosts, and the disease is potentially zoonotic. After ingestion by a definitive host, the tetrathyridium can occasionally migrate through the intestinal wall and reach the peritoneal cavity or abdominal organs causing peritoneal metacestodosis. Here, we report on a case of metacestodosis of a European wild cat (
Felis silvestris silvestris
) found dead in Croatia. At necropsy, a large number of white, rice-like structures were found free in the abdominal and thoracic cavities, as well as along the serous surfaces and in the lungs. DNA isolated from the nodules was genotyped and based on a 320-base pair long 12S fragment classified as
Mesocestoides vogae
. Although post-mortem changes were advanced, severe emaciation due to the severe parasitic infection and gastrointestinal bleeding was diagnosed as the likely cause of death. Intestinal cestodosis was previously reported in wild cats, but according to our knowledge, this is the first description of peritoneal and pleural metacestodosis caused by
M. vogae
tetrathyridia (metacestodes) in any wild carnivore species.
Large American liver fluke (Fascioloides magna) was introduced to Europe at least twice, via invaded North American deer species. These imports resulted in formation of three permanent foci of ...fascioloidosis - Italian, Czech and Danube floodplain forests. Molecular analysis revealed that flukes in Italian foci represent separate genetic group, and that flukes from Czech and Danube foci are genetically identical. Since previous studies of genetic structure of F. magna from Croatia were based on samples collected from red deer in one limited area (Baranja), the aim of this study was to analyse genetic diversity of 111 fluke samples collected from various hosts (red, roe and fallow deer, wild boar) and geographic locations in Croatia. On 355 base pair long cytochrome oxidase subunit 1 sequence, three haplotypes were identified - previously published CO1-Ha3 and CO1-Ha4, and one new haplotype named CO1-Ha36. Results obtained in our study confirmed as expected, that F. magna in Croatia has a Danube origin and that haplotypes are shared among different final host species.
Alveolar echinococcosis, caused by the tapeworm Echinococcus multilocularis, is one of the world's most dangerous zoonosis and an emerging disease with growing incidence in humans. The disease has ...been reported in new areas and host species in the last two decades, and the primary hosts of the parasite - red fox, golden jackal and grey wolf - are expanding their distribution in Europe. Here we report the morphological and molecular identification of Echinococcus multilocularis tapeworms in one of 29 carcasses of adult golden jackals in Croatia, where the only previous report of the parasite was in red foxes in 2016. These results suggest that alveolar echinococcosis should be treated as an emerging disease in Croatia.