Context
Connectivity assessments typically rely on resistance surfaces derived from habitat models, assuming that higher-quality habitat facilitates movement. This assumption remains largely untested ...though, and it is unlikely that the same environmental factors determine both animal movements and habitat selection, potentially biasing connectivity assessments.
Objectives
We evaluated how much connectivity assessments differ when based on resistance surfaces from habitat versus movement models. In addition, we tested how sensitive connectivity assessments are with respect to the parameterization of the movement models.
Methods
We parameterized maximum entropy models to predict habitat suitability, and step selection functions to derive movement models for brown bear (
Ursus arctos
) in the northeastern Carpathians. We compared spatial patterns and distributions of resistance values derived from those models, and locations and characteristics of potential movement corridors.
Results
Brown bears preferred areas with high forest cover, close to forest edges, high topographic complexity, and with low human pressure in both habitat and movement models. However, resistance surfaces derived from the habitat models based on predictors measured at broad and medium scales tended to underestimate connectivity, as they predicted substantially higher resistance values for most of the study area, including corridors.
Conclusions
Our findings highlighted that connectivity assessments should be based on movement information if available, rather than generic habitat models. However, the parameterization of movement models is important, because the type of movement events considered, and the sampling method of environmental covariates can greatly affect connectivity assessments, and hence the predicted corridors.
The abundance and distribution of large carnivores in Europe have been historically reduced. Their recovery requires multilevel coordination, especially regarding transboundary populations. Here, we ...apply nuclear and mitochondrial genetic markers to test for admixture level and its impact on population genetic structure of contemporary brown bears (Ursus arctos) from the Eastern, Southern, and Western Carpathians. Carpathian Mountains (Europe). Nearly 400 noninvasive brown bear DNA samples from the Western (Poland) and Eastern Carpathians (Bieszczady Mountains in Poland, Slovakia, Ukraine) were collected. Together with DNA isolates from Slovakia and Romania, they were analyzed using the set of eight microsatellite loci and two mtDNA regions (control region and cytochrome b). A set of 113 individuals with complete genotypes was used to investigate genetic differentiation across national boundaries, genetic structuring within and between populations, and movement between populations. Transboundary brown bear subpopulations (Slovakia and Poland) did not show significant internal genetic structure, and thus were treated as cohesive units. All brown bears from the Western Carpathians carried mitochondrial haplotypes from the Eastern lineage, while the Western lineage prevailed in the brown bears from the Bieszczady Mountains. Despite similar levels of microsatellite variability, we documented significant differentiation among the studied populations for nuclear markers and mtDNA. We also detected male‐biased and asymmetrical movement into the Bieszczady Mountains population from the Western Carpathians. Our findings suggest initial colonization of the Western Carpathians by brown bears possessing mtDNA from the Eastern lineage. Genetic structuring among populations at microsatellite loci could be a result of human‐mediated alterations. Detected asymmetric gene flow suggests ongoing expansion from more abundant populations into the Bieszczady Mountains and thus supports a metapopulation model. The knowledge concerning this complex pattern can be implemented in a joint Carpathian brown bear management plan that should allow population mixing by dispersing males.
This study is focused on genetic differentiation among two transboundary Carpathian brown bear populations subjected to different conservation/management. We obtained results that are coherent for mitochondrial DNA and microsatellites, unveiling significant differentiation which is homogenized to some extent by male‐biased gene flow. These results can be implemented in a joint Carpathian brown bear management plan, pointing to retention of population connectivity via the Carpathian migratory corridor.
Phylogeographic studies of highly mobile large carnivores suggest that intra-specific genetic differentiation of modern species might be the consequence of the most recent Pleistocene glaciation. ...However, the relative influence of biogeographical processes and subsequent human-induced population fragmentation requires a better understanding. Poland represents the western edge of relatively continuous distributions of many wide-ranging species, e.g. lynx (
Lynx lynx
), wolves (
Canis lupus
), moose (
Alces alces
) and, therefore, a key area for understanding historic and contemporary patterns of gene flow in central Europe. We examined wolf genetic structure in Poland and in a recently recolonized area in eastern Germany using microsatellite profiles (
n
= 457) and mitochondrial DNA sequencing (mtDNA,
n
= 333) from faecal samples. We found significant genetic structure and high levels of differentiation between wolves in the Carpathian Mountains and the Polish lowlands. Our findings are consistent with previously reported mtDNA subdivision between northern lowlands and southern mountains, and add new and concordant findings based on autosomal marker variation. Wolves in western Poland and eastern Germany showed limited differentiation from northeastern Poland. Although the presence of private alleles suggests immigration also from areas not sampled in this study, most individuals seem to be immigrants from northeastern Poland or their descendants. We observed moderate genetic differentiation between certain northeastern lowland regions separated by less than 50 km. Moreover, mtDNA results indicated a southeastern subpopulation near the border with Ukraine. The observed structure might reflect landscape fragmentation and/or ecological differences resulting in natal habitat-biased dispersal.
Following protection measures implemented since the 1970s, large carnivores are currently increasing in number and returning to areas from which they were absent for decades or even centuries. ...Monitoring programmes for these species rely extensively on non‐invasive sampling and genotyping. However, attempts to connect results of such studies at larger spatial or temporal scales often suffer from the incompatibility of genetic markers implemented by researchers in different laboratories. This is particularly critical for long‐distance dispersers, revealing the need for harmonized monitoring schemes that would enable the understanding of gene flow and dispersal dynamics. Based on a review of genetic studies on grey wolves Canis lupus from Europe, we provide an overview of the genetic markers currently in use, and identify opportunities and hurdles for studies based on continent‐scale datasets. Our results highlight an urgent need for harmonization of methods to enable transnational research based on data that have already been collected, and to allow these data to be linked to material collected in the future. We suggest timely standardization of newly developed genotyping approaches, and propose that action is directed towards the establishment of shared single nucleotide polymorphism panels, next‐generation sequencing of microsatellites, a common reference sample collection and an online database for data exchange. Enhanced cooperation among genetic researchers dealing with large carnivores in consortia would facilitate streamlining of methods, their faster and wider adoption, and production of results at the large spatial scales that ultimately matter for the conservation of these charismatic species.
Home-range size of Eurasian lynx Lynx lynx was studied in two different mountain ranges of the Polish Carpathians during 1999-2004. We live-trapped and radio-collared five adult lynx (two males and ...three females). One female was probably killed only 10 days after being radio-collared. Home-range size of radio-collared individuals calculated for the whole period of radio-tracking (MCP with 100% observations) was 164 km2 for male M1 from the Beskid Sądecki Mountains, and it was 124 and 190 km2, respectively, for the two females F1 and F2 and 199 km2 for male M2 in the Bieszczady Mountains.
Abstract
Following protection measures implemented since the 1970s, large carnivores are currently increasing in number and returning to areas from which they were absent for decades or even ...centuries. Monitoring programmes for these species rely extensively on non‐invasive sampling and genotyping. However, attempts to connect results of such studies at larger spatial or temporal scales often suffer from the incompatibility of genetic markers implemented by researchers in different laboratories. This is particularly critical for long‐distance dispersers, revealing the need for harmonized monitoring schemes that would enable the understanding of gene flow and dispersal dynamics.
Based on a review of genetic studies on grey wolves
C
anis lupus
from
E
urope, we provide an overview of the genetic markers currently in use, and identify opportunities and hurdles for studies based on continent‐scale datasets.
Our results highlight an urgent need for harmonization of methods to enable transnational research based on data that have already been collected, and to allow these data to be linked to material collected in the future. We suggest timely standardization of newly developed genotyping approaches, and propose that action is directed towards the establishment of shared single nucleotide polymorphism panels, next‐generation sequencing of microsatellites, a common reference sample collection and an online database for data exchange.
Enhanced cooperation among genetic researchers dealing with large carnivores in consortia would facilitate streamlining of methods, their faster and wider adoption, and production of results at the large spatial scales that ultimately matter for the conservation of these charismatic species.
Although the increasing body of knowledge in the field of immunohistochemistry and molecular biology has allowed for better understanding of the biology of breast cancer; nevertheless, a search is ...still in progress for new factors that would make it possible to preselect patients and employ target therapies. Predictive factors that arouse interest include topoisomerases. The authors evaluated the response to treatment and survival rates depending on expression of topoisomerase II alpha (TOP2A) and other predictive factors, as well as assessed treatment effectiveness employing therapeutic schemes based on anthracycline depending on TOP2A expression. The investigations demonstrated that the response to treatment and survival of patients with TOP2A expression were similar to the response and survival of those with tumours demonstrating the presence of other recognized predictors. The employed adjuvant therapy according to anthracycline therapeutic protocols was markedly more effective in TOP2A-positive patients as compared to the remaining individuals. Thus, TOP2A constituted a predictive factor. The study demonstrated that in adjuvant therapy employed in infiltrating ductal carcinoma of the breast, not only HER2 but also TOP2A determination in cancer cells was of importance; for this reason, routine determinations by immunohistochemistry should be performed, especially when anthracycline treatment is planned.
Parasitological surveys of freshwater fishes rarely include comparisons between two ecologically different bodies of water. Such studies might help to understand processes of establishment of ...parasite faunas in estuary areas. The results obtained could also provide useful tools for discriminating various fish populations based on the composition of their parasite faunas. The present authors attempted to study such data from Resko Lake-a freshwater coastal lagoon (6 km2 surface area), and the adjacent areas of the Baltic Sea. Resko Lake, located 12 km west of the city of Kołobrzeg, is shallow (1.5 m) and is connected to the sea through a small canal (1.3 km long, 30 m wide).
The material was collected from April 1969 and July 1970. A total of 159 perch were collected, in this number 104 fish from the lake, 43 from the sea, and 12 from the canal.
A total of 32 parasite species were recovered from the fish necropsied. The parasites represented 7 higher taxa: Protozoa (3 species), Cestoda (4), Digenea (13), Nematoda (5), Acanthocephala (3), Mollusca (1), and Crustacea (3). The parasite fauna of perch from the sea was definitely more abundant (31 species) compared to that of the lake (21), and the canal (12 species). Infection parameters of 13 parasite species demonstrated significant differences between the locations studied. The infection level of 6 parasite species was significantly higher in perch from the sea: Bothriocephalus scorpii, Ligula sp., Brachyphallus crenatus, Camallanus truncatus, Hysterothylacium aduncum, and Echinorhynchus gadi. On the other hand, infection levels of 7 other species were higher at the lake: Triaenophorus nodulosus, Bucephalus polymorphus, Azygia lucii, Tylodelphys clavata, Camallanus lacustris, Acanthocephalus lucii, and Achtheres percarum. The infection parameters of the fish from canal were similar to those from the lake. Interesting observations were made on the seasonality of certain parasites of both lake- and Baltic perch. The presently observed differences between parasite faunas of the fish from ecologically different adjacent estuarine locations are certainly caused by diversified environmental conditions that affected the processes of formation of the parasite communities there. Among important factors that could affect compositions of the parasite faunas could have been: availability of the intermediate hosts, exchange of waters (Baltic water influxes to the lake), fish migrations (spawning), and finally the separate identity of the two fish stocks studied.
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