Context
Romania is currently one of the best-connected landscapes, with high-quality habitats and a high density of brown bears. However, regional development measures are needed for the nation’s ...economic growth, and without responsible government actions, these measures pose a threat to brown bear connectivity, a vital pillar of the entire Carpathian region. Despite having important implications for the species conservation, bears sex-specific behaviour has been overlooked in connectivity assessments.
Objectives
The study’s main goals were to (i) develop sex-specific distribution and connectivity models, (ii) assess the movement patterns differences between females and males, and (iii) identify high-quality areas to be secured for species connectivity conservation.
Methods
We designed a methodological framework based on interdisciplinary approaches and modelling tools for landscape connectivity combined with novel spatial analysis. Telemetry data of sixteen bears (females and males) were utilized to predict habitat selection (MaxEnt), and circuit-theoretic approaches (Circuitscape) were applied to identify the potential movement corridors of both sexes and high-priority areas.
Results
The obtained results provided new evidence on the uneven movement patterns and pathways used by males and females in the study region. Males’ movement preferences were related to river shores and dense forest coverage areas, avoiding urban areas, while females were predicted to move across forested and open areas and were more tolerant to human‐modified areas. Three high-quality areas were delineated for both sexes, and connectivity conservation efforts are needed due to the vicinity of anthropic pressures.
Conclusions
This study depicts the usefulness of combining interdisciplinary approaches and provides planners, managers, and decision-makers with practical solutions to address sustainable design and management within the intervened landscapes. Using separate female and male spatial models for leading management and conservation measures, setting connectivity targets within environmental and impact assessments while adopting conservation easements could secure a safety network for biodiversity conservation in the Carpathians.
Once exploited for fur, meat, and extracting the yellowish exudate called castoreum, the Eurasian beaver disappeared from Romania during the eighteenth century. After, the reintroductions carried out ...two decades ago are currently thriving in the Danube River basin. Using nine nSSR markers, we analysed samples from 98 individuals, and we found no genetic substructure, suggesting high dispersal and gene flow capabilities. The stepwise mutation model (SMM) indicated the existence of a recent genetic bottleneck, though the Eurasian beaver retains high levels of genetic diversity and population growth facilitated variation in nSSR loci. A fine-scale spatial correlation in females was detected, contrasting with males’ dispersal on longer distances. While the movement and establishment of individuals’ new territories were made under natural predation pressure, the mix following natural expansion improved the fitness and could contribute to a higher genetic diversity than the source population. With any reintroduction, a focus on capturing individuals from various geographic origins, as well as securing many and suitable founding individuals (adults, subadults, and juveniles) with mixed origins, could secure the post-genetic bottleneck recovery and higher genetic diversity. Beyond this conservation success, future management strategies should consider building a National Action Plan (NAP) for the species, including a permanent genetic monitoring programme for Eurasian beaver.
Road development, traffic intensification, and collisions with wildlife represent a danger both for road safety and species conservation. For planners, deciding which mitigation methods to apply is ...often problematic. Through a kernel density estimate, we analyzed 715 crossing locations and wildlife–vehicle collisions (WVCs) involving brown bears, lynx, wolf, red deer, roe deer, and wild boar in the Southeastern Carpathian Mountains. We identified 25 WVC hotspots, of which eight require urgent mitigation of existing infrastructure. Moreover, many of these hotspots are in Natura 2000 sites, along road sections where vegetation is in close proximity, animal movement is the highest, and driver visibility is low. Our study is the first in Romania to recommend practical solutions to remediate WVC hotspots and benefit sustainable landscape management.
Genetic monitoring represents a valuable tool for natural resource managers in managing and conserving wild populations of plants and animals. Even though there is a clear need to establish genetic ...monitoring programmes urgently, several barriers could occur depending on the region, such as lack of funding, gaps in national strategies, poor international collaboration, and transboundary issues. This review aims to analyze the genetic and non-genetic variables used in previous studies and projects to reveal the premises for conducting genetic studies on multispecies using existing knowledge. However, we found that sex marker, the number of samples per individual per year, and the rate of non-invasive samples were correlated with each other, as well as the number of sample types used and monitoring time. We show that developing nations are indeed challenged by the cost of large-scale and temporal coverage of the genetic studies. In contrast, high amounts of funds, complex methods, and national genetic monitoring programs are concentrated in well-developed countries, and the results are providing powerful tools for both species management and long-term conservation.
In this study we tested a newly-developed instrument (an automatized DNA extractor MAxWell16-Promega), in order to test if DNA isolation can be performed more efficiently on feacal samples collected ...from three different species: bears, wolfs and capercaillies. We also evaluate a simple method for samples preservation in the field, which include the preservation of faeces in vials filled with ethanol (90%). This method we have used is fast and simple. The time spent for isolating DNA from each batch of 16 samples is approximately 38 min, no further processes needed. The extracted DNA can be used immediately in the downstream analyses. No further wash of the samples, or other purification method is needed. The DNA should not be diluted for the amplification step, likewise the PCR product is not recommended to be diluted for the fragment analysis step.
Long term analyses on habitat dynamics are challenging when data from the past is scarce. In addition, large scale perspectives are difficult to attain without proper modelling of habitat conditions. ...These drawbacks were overcome in the case of capercaillie in Romania with the help of satellite-based information and by finding relevant environmental variables which influence the species habitat. We used MaxEnt software with four variables (spruce distribution, elevation, precipitation and temperature in June) and 750 presence points. The model had a high predictive ability (area under the curve over 95%), elevation and spruce distribution being the most important variables. A separate set of 902 presence points was used for model crosschecking. Most of the crosscheck points (98.6%) fell inside the predicted habitat confirming the model performance. To detect habitat preferences the vegetation mosaic in 90 circles (3 km-radius) was analyzed using both historical (Cold War) and recent satellite information. The modelled habitat across the Romanian Carpathians was a mosaic of stands of different ages. Moreover, a similar structure was found inside and outside the analyzed circles: forests between 65 and 120 yr. dominated, followed by the younger classes (20–65 yr. and forests <20 yr.). The oldest class (> 120 yr.) was the least common. The majority (i.e., 90%) of the presence points used for model crosscheck fell within actively managed forests, including former large clearcuts (revealed by the Cold War spy-satellite images). This suggests that the species was tolerant to forest management and also able to recolonize areas when habitat became favorable again. Therefore, controlled forest management maintains the habitat favorability at very large scales in a shifting steady-state mosaic. This management-driven habitat together with the one produced by natural disturbances in natural forests provides favorable conditions for a habitat continuum along the Romanian Carpathians.
Display omitted
•Capercaillie habitat can be modelled with a low number of environmental variables.•In the Romanian Carpathians capercaillie follows the Norway spruce distribution.•Old spy-satellite images reveal important information on past capercaillie habitat.•Controlled forest management maintains habitat favorability at very large scales.•Capercaillie persists in managed “shifting steady-state mosaic” forested landscapes.
While many initiatives, studies and projects are focusing only on modelling wildlife connectivity movement, coordinated efforts should help to deliver adaptative solutions for the on-the-ground ...needs, while helping the planners and involving communities in landscape protection. Multispecies spatial models and maps allow the generalisation of findings across more significant regions and provide insights to maintain, improve or restore landscape connectivity, while individual species could contribute in establishing regions of focus in conservation efforts. Given the challenge of multispecies connectivity, we chose to build single connectivity models through circuit theory for brown bear, wolf, red deer, wild boar and roe deer. Further, we combined best-supported models in a regional cumulative spatial map, on which we identified areas of high importance for connectivity conservation to investigate and mitigate the impact of linear infrastructure. Results for carnivores and their prey species were similar to those obtained from brown bear landscape genetics modelling. Eastern slope facing was a clear preference of multispecies, and we trust this is due to abundant vegetation, food resources, and lack of fragmentation of forest regions. A vital area called Cold River corridor was validated both functional (brown bear) and structural (for carnivores and prey species) by this study and the results from previous research. However, a highway is planned to bisect the Cold River for the first time, and we advocate that the remaining conservation potential of the area should be maintained whenever possible while planning for evolutionary resilience and prioritizing management actions and effective strategies for all the species. Conservation easements could provide protections against development considered together with coordinated efforts for "smart development", and maintenance of existing forest and wildlife management and land uses preservation.
In recent decades, ungulates have expanded in number and range in Europe. This review aims to analyze the impact of ungulate browsing in different forest ecosystems and identify the main driving ...factors and trends. In total, 155 studies were analyzed in preparing this review, across 19 European countries. In Europe, the main browsers are represented by roe deer (Capreolus capreolus L.), red deer (Cervus elaphus L.), moose (Alces alces L.), chamois (Rupicapra rupicapra L.), and fallow deer (Dama dama L.). Regarding browsing severity, they frequently exceeded 50%, meaning that over half of the saplings were browsed. Ungulate density was the main driving factor of browsing severity, with areas exhibiting high browsing pressure often having more than ten individuals per square kilometer. The type of silvicultural system used played a vital role in the severity of browsing, and trends in foraging for preferred tree species were identified. Fencing was the most common non-harmful protection method used, while hunting management was the most efficient method for controlling deer numbers and browsing intensity. Large carnivores were missing in most study areas, but in the areas where they were present, they played a significant role in creating a chain reaction of ecological impacts. Considering the significant impact of ungulate browsing on forest ecosystems, there is a pressing need for more research to comprehend and effectively mitigate the effects of deer presence comprehensively.
Infanticide is a significant evolutionary force influencing carnivore behaviours, as it is one of the primary contributors to offspring mortality. Female multimale mating, which creates paternal ...uncertainty, is known to reduce infanticide. We propose that two crucial steps are needed for this strategy to work in solitary species like brown bears, Ursus arctos. First, after mating, females should choose dens within their mating area (step 1), boosting the chances of encountering potential fathers of cub(s) after den emergence in spring. However, the efficacy of this strategy hinges on males' fidelity to the same mating areas from one year to the next (step 2). Our study confirmed that pregnant females consistently selected dens within their mating areas, with significant overlap (around 90%) between areas used by females with cubs and their mating zones. Males also demonstrated fidelity (over 65%) to mating areas over 2 consecutive years. Infanticide significantly shapes the sociospatial ecology of female brown bears, a phenomenon that can carry nutritional costs for females with cubs, and influence settlement patterns near human shields to increase reproductive success. Additionally, in hunted populations, removing resident males can trigger an influx of potentially infanticidal bears from elsewhere.
•Infanticide represents one of the main causes of offspring mortality in carnivores.•Natural selection has favoured several behavioural counterstrategies in females.•Female bear multimale mating reduces infanticide by creating paternal uncertainty.•Males show fidelity to the same mating areas from one year to the next.•Females with cubs remain in the mating area to increase chances of meeting fathers.
Adult bear individuals live solitary and haveprolonged parent-offspring relationships, therefore the share of learned skills compared to the inherited ones is much larger than in other carnivores. ...This promotes acquisition of deviated behavior and simultaneously establishment of a kinship structure. However, deviated bear behavior and human food conditioning are the symptoms of habituation. The aim of this paper is to test the genetic structuring of habituated and non-habituated individuals located in the central region of Romania (Brasov and Prahova districts), a hotspot in terms of human-bear conflicts. Seven microsatellites were used to genotype 145 samples (ear clips and tissue), out of which 82 were classified as habituated and 63 as wild individuals, respectively. Our results suggest the presence of kinship structures in habituated bear group and a reduction of genetic diversity (He = 0.75), while the group located in the wild registered a higher genetic diversity (He = 0.78) and more private alleles. The genetic differentiation suggested by the Neighbor joining cluster analysis has been strengthened by the two percent (AMOVA) differences between the two groups and highlights the negative impact of brown bear kinship structure, caused by the human expansion on wilderness. The genetic analyses indicated that the two groups share genetic variants due to the dispersal and breeding patterns of male adult bears. The emergence of genetic differences between the two groups can be avoided by preventing bears to become human-food conditioned; over time, kinship structure can pose a threat to genetic diversity.
PDF
