553 research outputs found
Spatial behaviour of wild boar
The spatial behaviour of an animal is influenced by decisions relating to foraging, movement, avoidance, resting, territorial activity, mating and rearing young. Many of these behaviours can be explained by the optimal foraging theory, exceptions being reproductive behaviours and predator avoidance. Predation risk and associated avoidance behaviors varies across the landscape, resulting in a divergence from patterns predicted by optimal foraging theory, instead optimizing fitness. Such risk effects can be large and affect both individuals and population demography. This thesis focus on external factors affecting movements and habitat selection of wild boar females (N=15-17 depending on the question) using data from GPS collared individuals (N>100.000 data points analyzed) over 4 years in the southern part of Sweden.
My results show that habitat selection is affected by season and by risk effects, such as traffic and hunting. Intense traffic diverts wild boar from crossing roads, and reduce the number of traffic accidents when traffic intensity is high. Intense hunting results in fleeing while less intense hunting results in hiding. Hunts that results in flights affects habitat selection until wild boar returned to their homer range. Wild boar perceive crop fields as risky but rewarding habitats, and while using crop fields they prefer to be close to cover such as edges, hedges and ditches. Further, wild boar movement is affected by seasonal and temporal aspects and weather conditions. The most common reaction to stressful factors such as traffic, hunting and aversive weather was to reduce movement. The only exception was when wild boar were chased in drive hunts and fled.
These results are important for understanding how weather conditions affect optimal foraging strategies and how the animalsâ perception of risk affects movement patterns and habitat selection. From a management perspective, my results can be used to reduce crop damages and traffic accidents caused by wild boar. These findings are also useful in understanding how hunting as a management tool affects the space use of wild boar, and consequently can aid managers to select hunting methods that may reduce damages to crops
Monitoring of species' genetic diversity in Europe varies greatly and overlooks potential climate change impacts
Genetic monitoring of populations currently attracts interest in the context of the Convention on Biological Diversity but needs long-term planning and investments. However, genetic diversity has been largely neglected in biodiversity monitoring, and when addressed, it is treated separately, detached from other conservation issues, such as habitat alteration due to climate change. We report an accounting of efforts to monitor population genetic diversity in Europe (genetic monitoring effort, GME), the evaluation of which can help guide future capacity building and collaboration towards areas most in need of expanded monitoring. Overlaying GME with areas where the ranges of selected species of conservation interest approach current and future climate niche limits helps identify whether GME coincides with anticipated climate change effects on biodiversity. Our analysis suggests that country area, financial resources and conservation policy influence GME, high values of which only partially match species' joint patterns of limits to suitable climatic conditions. Populations at trailing climatic niche margins probably hold genetic diversity that is important for adaptation to changing climate. Our results illuminate the need in Europe for expanded investment in genetic monitoring across climate gradients occupied by focal species, a need arguably greatest in southeastern European countries. This need could be met in part by expanding the European Union's Birds and Habitats Directives to fully address the conservation and monitoring of genetic diversity.Comparing data on genetic monitoring efforts across Europe with the distributions of areas at species' climatic niche margins, the authors show that monitoring efforts should be expanded to populations at trailing niche margins to include genetic variation that may prove important for adaptation to ongoing climate warming
Multinational evaluation of genetic diversity indicators for the Kunming-Montreal Global Biodiversity Framework
Under the recently adopted Kunming-Montreal Global Biodiversity Framework, 196 Parties committed to reporting the status of genetic diversity for all species. To facilitate reporting, three genetic diversity indicators were developed, two of which focus on processes contributing to genetic diversity conservation: maintaining genetically distinct populations and ensuring populations are large enough to maintain genetic diversity. The major advantage of these indicators is that they can be estimated with or without DNA-based data. However, demonstrating their feasibility requires addressing the methodological challenges of using data gathered from diverse sources, across diverse taxonomic groups, and for countries of varying socio-economic status and biodiversity levels. Here, we assess the genetic indicators for 919 taxa, representing 5271 populations across nine countries, including megadiverse countries and developing economies. Eighty-three percent of the taxa assessed had data available to calculate at least one indicator. Our results show that although the majority of species maintain most populations, 58% of species have populations too small to maintain genetic diversity. Moreover, genetic indicator values suggest that IUCN Red List status and other initiatives fail to assess genetic status, highlighting the critical importance of genetic indicators.We assess two genetic indicators for 919 taxa, representing 5271 populations in nine countries, including megadiverse countries and developing economies. The majority of taxa assessed (83%) had data available to calculate at least one indicator. Although most species assessed have most populations maintained (Populations maintained indicator), a large percentage of species' populations are too small to maintain genetic diversity (Ne 500 indicator). Genetic indicators can be calculated quickly and affordably.imag
Practical application of indicators for genetic diversity in CBD post-2020 global biodiversity framework implementation
Genetic diversity is a key aspect of biological variation for the adaptability and survival of populations of species and must be monitored to assure maintenance. We used data from the Swedish Red List 2020 and from published reviews to apply three indicators for genetic diversity proposed for the post-2020 Global Biodiversity Framework of the Convention on Biological Diversity (CBD). We studied a wide range of taxonomic groups, and made more detailed indicator assessments for mammals and herptiles.For indicator 1, the proportion of populations with effective population size Ne > 500, 33% of 22,557 investigated species had a population size estimate that could be used as a proxy for Ne. For herptiles and mammals, 70% and 49% of populations of species, respectively, likely had Ne > 500.Data for evaluation of indicator 2, the proportion of remaining populations or historical range, was available for 20% of all species evaluated for the Red List. Meanwhile, 32% of the herptile and 84% of the mammal populations are maintaining their populations and range.For indicator 3, the number of species or populations in which genetic diversity is monitored using DNA-based methods, there are genetic studies on 3% of all species, and 0.3% are beeing monitored genetically. In contrast, 68% of mammals and 29% of herptiles are studied using DNA, and 8% of mammals and 24% of herptiles are genetically monitored.We conclude that the Red List provides data that are suitable for evaluating the genetic indicators, but the data quality can be improved. We also show that the genetic indicators capture conservation issues of genetic erosion that the Red List misses. There is a synergy in estimating the genetic indicators in parallel with the Red Listing process. We propose that indicator values could be included in national Red Listing as a new category "genetically threatened", based on the genetic indicators
Trafikantinformation i stationsmiljöer
The aim of the thesis is to study and highlight the needs of passengerâs traffic information in the railway station environment, to identify and examine what its deficiencies depend on and come up with proposals on how they can be addressed. Thus, hopefully, improve the quality of information reaching the passengers in station environments. The method used included literature studies, among others, perception theory, which together with interviews, a focus group and field studies formed the basis for the analysis. The work has focused at the average traveller, therefore have groups with special needs such as disabled, visually impaired or children not been studied specifically
Density-dependent dinner: Wild boar overuse agricultural land at high densities
The Swedish wild boar (Sus scrofa) population has increased rapidly over the last decades, resulting in conflicts with human activities. Particularly, the increase has been challenging for agriculture as wild boar cause damage on crops and grasslands. To predict under what conditions to expect damage and where to prioritize management actions, basic knowledge about wild boar habitat and space use is needed. In this study, we used data from 99 wild boar equipped with GPS-collars, collected over a large temporal scale and throughout their distributional range in southern Sweden. We investigated wild boar home range size and habitat use across gradients of habitat availability and population density. Functional response in habitat use was assessed by estimating the use and availability of agricultural land on individual level and then, on population-level evaluating how use changed with changing availability. Finally, a potential response in habitat use was evaluated in relation to population density, i.e., the interaction between availability and population density. Home range size was negatively related to population density for both male and female wild boar. Wild boar used agricultural land more intensively with increasing population density and when other habitat types were less available. Our findings show that wild boar spatial behavior is highly context dependent and may vary considerably due to landscape characteristics and local conditions. Wild boars tend to overuse agricultural land at high densities which has strong implications for wildlife management. It is therefore important to consider local conditions when predicting space and habitat use by wild boar. Overall, this study provided a better understanding of the drivers of wild boar distribution and space use in agro-forested mosaic landscapes and how this knowledge can improve management practices
Lessons from integrating behaviour and resource selection: activity-specific responses of African wild dogs to roads
Understanding how anthropogenic features affect species' abilities to move within landscapes is essential to conservation planning and requires accurate assessment of resource selection for movement by focal species. Yet, the extent to which an individual's behavioural state (e.g. foraging, resting, commuting) influences resource selection has largely been ignored. Recent advances in Global Positioning System (GPS) tracking technology can fill this gap by associating distinct behavioural states with location data. We investigated the role of behaviour in determining the responses of an endangered species of carnivore, the African wild dog Lycaon pictus, to one of the most widespread forms of landscape alteration globally: road systems. We collected highâresolution GPS and activity data from 13 wild dogs in northern Botswana over a 2âyear period. We employed a step selection framework to measure resource selection across three behavioural states identified from activity data (highâspeed running, resting and travelling) and across a gradient of habitats and seasons, and compared these outputs to a full model that did not parse for behaviour. The response of wild dogs to roads varied markedly with both the behavioural and the landscape contexts in which roads were encountered. Specifically, wild dogs selected roads when travelling, ignored roads when highâspeed running and avoided roads when resting. This distinction was not evident when all movement data were considered together in the full model. When travelling, selection for roads increased in denser vegetative environments, suggesting that roads may enhance movement for this species. Our findings indicate that including behavioural information in resource selection models is critical to understanding wildlife responses to landscape features and suggest that successful application of resource selection analyses to conservation planning requires explicit examination of the behavioural contexts in which movement occurs. Thus, behaviourâspecific step selection functions offer a powerful tool for identifying resource selection patterns for animal behaviours of conservation significance
Transmission routes of African swine fever virus to domestic pigs: current knowledge and future research directions
African swine fever (ASF) is a major threat to the pig industry in Europe. Since 2007, ASF outbreaks have been ongoing in the Caucasus, Eastern Europe and the Baltic countries, causing severe economic losses for many pig farmers and pork producers. In addition, the number of ASF cases in wild boar populations has dramatically increased over the past few years. Evidence supports direct contact with infectious domestic pigs and wild boars, and consumption of contaminated feed, as the main transmission routes of ASF virus (ASFV) to domestic pigs. However, significant knowledge gaps highlight the urgent need for research to investigate the dynamics of indirect transmission via the environment, the minimal infective doses for contaminated feed ingestion, the probability of effective contacts between infectious wild boars and domestic pigs, the potential for recovered animals to become carriers and a reservoir for transmission, the potential virus persistence within wild boar populations and the influence of human behaviour for the spread of ASFV. This will provide an improved scientific basis to optimise current interventions and develop new tools and strategies to reduce the risk of ASFV transmission to domestic pigs.ISSN:0042-490
Computer-assisted mammographic imaging
Computer-assisted mammography imaging comprises computer-based analysis of digitized images resulting in prompts aiding mammographic interpretation and computerized stereotactic localization devices which improve location accuracy. The commercial prompting systems available are designed to draw attention to mammographic abnormalities detected by algorithms based on symptomatic practise in North America. High sensitivity rates are important commercially but result in increased false prompt rates, which are known to distract radiologists. A national shortage of breast radiologists in the UK necessitates evaluation of such systems in a population breast screening programme to determine effectiveness in increasing cancer detection and feasibility of implementation
- âŠ