@phdthesis{Stiegler2023,
  author    = {Stiegler, Jonas},
  title     = {Mobile link functions in unpredictable agricultural landscapes},
  doi       = {10.25932/publishup-62202},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-622023},
  school      = {Universit{\"a}t Potsdam},
  pages     = {155},
  year      = {2023},
  abstract  = {Animal movement is a crucial aspect of life, influencing ecological and evolutionary processes. It plays an important role in shaping biodiversity patterns, connecting habitats and ecosystems. Anthropogenic landscape changes, such as in agricultural environments, can impede the movement of animals by affecting their ability to locate resources during recurring movements within home ranges and, on a larger scale, disrupt migration or dispersal. Inevitably, these changes in movement behavior have far-reaching consequences on the mobile link functions provided by species inhabiting such extensively altered matrix areas. In this thesis, I investigate the movement characteristics and activity patterns of the European hare (Lepus europaeus), aiming to understand their significance as a pivotal species in fragmented agricultural landscapes. I reveal intriguing results that shed light on the importance of hares for seed dispersal, the influence of personality traits on behavior and space use, the sensitivity of hares to extreme weather conditions, and the impacts of GPS collaring on mammals' activity patterns and movement behavior. In Chapter I, I conducted a controlled feeding experiment to investigate the potential impact of hares on seed dispersal. By additionally utilizing GPS data of hares in two contrasting landscapes, I demonstrated that hares play a vital role, acting as effective mobile linkers for many plant species in small and isolated habitat patches. The analysis of seed intake and germination success revealed that distinct seed traits, such as density, surface area, and shape, profoundly affect hares' ability to disperse seeds through endozoochory. These findings highlight the interplay between hares and plant communities and thus provide valuable insights into seed dispersal mechanisms in fragmented landscapes. By employing standardized behavioral tests in Chapter II, I revealed consistent behavioral responses among captive hares while simultaneously examining the intricate connection between personality traits and spatial patterns within wild hare populations. This analysis provides insights into the ecological interactions and dynamics within hare populations in agricultural habitats. Examining the concept of animal personality, I established a link between personality traits and hare behavior. I showed that boldness, measured through standardized tests, influences individual exploration styles, with shy and bold hares exhibiting distinct space use patterns. In addition to providing valuable insights into the role of animal personality in heterogeneous environments, my research introduced a novel approach demonstrating the feasibility of remotely assessing personality types using animal-borne sensors without additional disturbance of the focal individual. While climate conditions severely impact the activity and, consequently, the fitness of wildlife species across the globe, in Chapter III, I uncovered the sensitivity of hares to temperature, humidity, and wind speed during their peak reproduction period. I found a strong response in activity to high temperatures above 25°C, with a particularly pronounced effect during temperature extremes of over 35°C. The non-linear relationship between temperature and activity was characterized by contrasting responses observed for day and night. These findings emphasize the vulnerability of hares to climate change and the potential consequences for their fitness and population dynamics with the ongoing rise of temperature. Since such insights can only be obtained through capturing and tagging free-ranging animals, I assessed potential impacts and the recovery process post-collar attachment in Chapter IV. For this purpose, I examined the daily distances moved and the temporal-associated activity of 1451 terrestrial mammals out of 42 species during their initial tracking period. The disturbance intensity and the speed of recovery varied across species, with herbivores, females, and individuals captured and collared in relatively secluded study areas experiencing more pronounced disturbances due to limited anthropogenic influences. Mobile linkers are essential for maintaining biodiversity as they influence the dynamics and resilience of ecosystems. Furthermore, their ability to move through fragmented landscapes makes them a key component for restoring disturbed sites. Individual movement decisions determine the scale of mobile links, and understanding variations in space use among individuals is crucial for interpreting their functions. Climate change poses further challenges, with wildlife species expected to adjust their behavior, especially in response to high-temperature extremes, and comprehending the anthropogenic influence on animal movements will remain paramount to effective land use planning and the development of successful conservation strategies. This thesis provides a comprehensive ecological understanding of hares in agricultural landscapes. My research findings underscore the importance of hares as mobile linkers, the influence of personality traits on behavior and spatial patterns, the vulnerability of hares to extreme weather conditions, and the immediate consequences of collar attachment on mammalian movements. Thus, I contribute valuable insights to wildlife conservation and management efforts, aiding in developing strategies to mitigate the impact of environmental changes on hare populations. Moreover, these findings enable the development of methodologies aimed at minimizing the impacts of collaring while also identifying potential biases in the data, thereby benefiting both animal welfare and the scientific integrity of localization studies.},
  language  = {en}
}
@phdthesis{Milles2022,
  author    = {Milles, Alexander},
  title     = {Sources and consequences of intraspecific trait variation in movement behaviour},
  doi       = {10.25932/publishup-56501},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-565011},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xvi, 225},
  year      = {2022},
  abstract  = {Variation in traits permeates and affects all levels of biological organisation, from within individuals to between species. Yet, intraspecific trait variation (ITV) is not sufficiently represented in many ecological theories. Instead, species averages are often assumed. Especially ITV in behaviour has only recently attracted more attention as its pervasiveness and magnitude became evident. The surge in interest in ITV in behaviour was accompanied by a methodological and technological leap in the field of movement ecology. Many aspects of behaviour become visible via movement, allowing us to observe inter-individual differences in fundamental processes such as foraging, mate searching, predation or migration. ITV in movement behaviour may result from within-individual variability and consistent, repeatable among-individual differences. Yet, questions on why such among-individual differences occur in the first place and how they are integrated with life-history have remained open. Furthermore, consequences of ITV, especially of among-individual differences in movement behaviour, on populations and species communities are not sufficiently understood. In my thesis, I approach timely questions on the sources and consequences of ITV, particularly, in movement behaviour. After outlining fundamental concepts and the current state of knowledge, I approach these questions by using agent-based models to integrate concepts from behavioural and movement ecology and to develop novel perspectives. Modern coexistence theory is a central pillar of community ecology, yet, insufficiently considers ITV in behaviour. In chapter 2, I model a competitive two-species system of ground-dwelling, central-place foragers to investigate the consequences of among-individual differences in movement behaviour on species coexistence. I show that the simulated among-individual differences, which matched with empirical data, reduce fitness differences betweem species, i.e. provide an equalising coexistence mechanism. Furthermore, I explain this result mechanistically and, thus, resolve an apparent ambiguity of the consequences of ITV on species coexistence described in previous studies. In chapter 3, I turn the focus to sources of among-individual differences in movement behaviour and their potential integration with life-history. The pace-of-life syndrome (POLS) theory predicts that the covariation between among-individual differences in behaviour and life-history is mediated by a trade-off between early and late reproduction. This theory has generated attention but is also currently scrutinised. In chapter 3, I present a model which supports a recent conceptual development that suggests fluctuating density-dependent selection as a cause of the POLS. Yet, I also identified processes that may alter the association between movement behaviour and life-history across levels of biological organization. ITV can buffer populations, i.e. reduce their extinction risk. For instance, among-individual differences can mediate portfolio effects or increase evolvability and, thereby, facilitate rapid evolution which can alleviate extinction risk. In chapter 4, I review ITV, environmental heterogeneity, and density-dependent processes which constitute local buffer mechanisms. In the light of habitat isolation, which reduces connectivity between populations, local buffer mechanisms may become more relevant compared to dispersal-related regional buffer mechanisms. In this chapter, I argue that capacities, latencies, and interactions of local buffer mechanisms should motivate more process-based and holistic integration of local buffer mechanisms in theoretical and empirical studies. Recent perspectives propose to apply principles from movement and community ecology to study filamentous fungi. It is an open question whether and how the arrangement and geometry of microstructures select for certain movement traits, and, thus, facilitate coexistence-stabilising niche partitioning. As a coauthor of chapter 5, I developed an agent-based model of hyphal tips navigating in soil-like microstructures along a gradient of soil porosity. By measuring network properties, we identified changes in the optimal movement behaviours along the gradient. Our findings suggest that the soil architecture facilitates niche partitioning. The core chapters are framed by a general introduction and discussion. In the general introduction, I outline fundamental concepts of movement ecology and describe theory and open questions on sources and consequences of ITV in movement behaviour. In the general discussion, I consolidate the findings of the core chapters and critically discuss their respective value and, if applicable, their impact. Furthermore, I emphasise promising avenues for further research.},
  language  = {en}
}
@phdthesis{Kuerschner2022,
  author    = {K{\"u}rschner, Tobias},
  title     = {Disease transmission and persistence in dynamic landscapes},
  doi       = {10.25932/publishup-56468},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-564689},
  school      = {Universit{\"a}t Potsdam},
  pages     = {120, LXXIII},
  year      = {2022},
  abstract  = {Infectious diseases are an increasing threat to biodiversity and human health. Therefore, developing a general understanding of the drivers shaping host-pathogen dynamics is of key importance in both ecological and epidemiological research. Disease dynamics are driven by a variety of interacting processes such as individual host behaviour, spatiotemporal resource availability or pathogen traits like virulence and transmission. External drivers such as global change may modify the system conditions and, thus, the disease dynamics. Despite their importance, many of these drivers are often simplified and aggregated in epidemiological models and the interactions among multiple drivers are neglected. In my thesis, I investigate disease dynamics using a mechanistic approach that includes both bottom-up effects - from landscape dynamics to individual movement behaviour - as well as top-down effects - from pathogen virulence on host density and contact rates. To this end, I extended an established spatially explicit individual-based model that simulates epidemiological and ecological processes stochastically, to incorporate a dynamic resource landscape that can be shifted away from the timing of host population-dynamics (chapter 2). I also added the evolution of pathogen virulence along a theoretical virulence-transmission trade-off (chapter 3). In chapter 2, I focus on bottom-up effects, specifically how a temporal shift of resource availability away from the timing of biological events of host-species - as expected under global change - scales up to host-pathogen interactions and disease dynamics. My results show that the formation of temporary disease hotspots in combination with directed individual movement acted as key drivers for pathogen persistence even under highly unfavourable conditions for the host. Even with drivers like global change further increasing the likelihood of unfavourable interactions between host species and their environment, pathogens can continue to persist with heir hosts. In chapter 3, I demonstrate that the top-down effect caused by pathogen-associated mortality on its host population can be mitigated by selection for lower virulent pathogen strains when host densities are reduced through mismatches between seasonal resource availability and host life-history events. I chapter 4, I combined parts of both theoretical models into a new model that includes individual host movement decisions and the evolution of pathogenic virulence to simulate pathogen outbreaks in realistic landscapes. I was able to match simulated patterns of pathogen spread to observed patterns from long-term outbreak data of classical swine fever in wild boar in Northern Germany. The observed disease course was best explained by a simulated high virulent strain, whereas sampling schemes and vaccination campaigns could explain differences in the age-distribution of infected hosts. My model helps to understand and disentangle how the combination of individual decision making and evolution of virulence can act as important drivers of pathogen spread and persistence. As I show across the chapters of this thesis, the interplay of both bottom-up and top-down processes is a key driver of disease dynamics in spatially structured host populations, as they ultimately shape host densities and contact rates among moving individuals. My findings are an important step towards a paradigm shift in disease ecology away from simplified assumptions towards the inclusion of mechanisms, such as complex multi-trophic interactions, and their feedbacks on pathogen spread and disease persistence. The mechanisms presented here should be at the core of realistic predictive and preventive epidemiological models.},
  language  = {en}
}
@article{KuerschnerSchererRadchuketal.2021,
  author    = {K{\"u}rschner, Tobias and Scherer, C{\´e}dric and Radchuk, Viktoriia and Blaum, Niels and Kramer-Schadt, Stephanie},
  title     = {Movement can mediate temporal mismatches between resource availability and biological events in host-pathogen interactions},
  series = {Ecology and evolution},
  volume    = {11},
  journal   = {Ecology and evolution},
  number    = {10},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {2045-7758},
  doi       = {10.1002/ece3.7478},
  pages     = {5728 -- 5741},
  year      = {2021},
  abstract  = {Global change is shifting the timing of biological events, leading to temporal mismatches between biological events and resource availability. These temporal mismatches can threaten species' populations. Importantly, temporal mismatches not only exert strong pressures on the population dynamics of the focal species, but can also lead to substantial changes in pairwise species interactions such as host-pathogen systems. We adapted an established individual-based model of host-pathogen dynamics. The model describes a viral agent in a social host, while accounting for the host's explicit movement decisions. We aimed to investigate how temporal mismatches between seasonal resource availability and host life-history events affect host-pathogen coexistence, that is, disease persistence. Seasonal resource fluctuations only increased coexistence probability when in synchrony with the hosts' biological events. However, a temporal mismatch reduced host-pathogen coexistence, but only marginally. In tandem with an increasing temporal mismatch, our model showed a shift in the spatial distribution of infected hosts. It shifted from an even distribution under synchronous conditions toward the formation of disease hotspots, when host life history and resource availability mismatched completely. The spatial restriction of infected hosts to small hotspots in the landscape initially suggested a lower coexistence probability due to the critical loss of susceptible host individuals within those hotspots. However, the surrounding landscape facilitated demographic rescue through habitat-dependent movement. Our work demonstrates that the negative effects of temporal mismatches between host resource availability and host life history on host-pathogen coexistence can be reduced through the formation of temporary disease hotspots and host movement decisions, with implications for disease management under disturbances and global change.},
  language  = {en}
}
@article{PottsSchlaegel2020,
  author    = {Potts, Jonathan R. and Schl{\"a}gel, Ulrike E.},
  title     = {Parametrizing diffusion-taxis equations from animal movement trajectories using step selection analysis},
  series = {Methods in ecology and evolution : an official journal of the British Ecological Society},
  volume    = {11},
  journal   = {Methods in ecology and evolution : an official journal of the British Ecological Society},
  number    = {9},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {2041-210X},
  doi       = {10.1111/2041-210X.13406},
  pages     = {1092 -- 1105},
  year      = {2020},
  abstract  = {Mathematical analysis of partial differential equations (PDEs) has led to many insights regarding the effect of organism movements on spatial population dynamics. However, their use has mainly been confined to the community of mathematical biologists, with less attention from statistical and empirical ecologists. We conjecture that this is principally due to the inherent difficulties in fitting PDEs to data. To help remedy this situation, in the context of movement ecology, we show how the popular technique of step selection analysis (SSA) can be used to parametrize a class of PDEs, calleddiffusion-taxismodels, from an animal's trajectory. We examine the accuracy of our technique on simulated data, then demonstrate the utility of diffusion-taxis models in two ways. First, for non-interacting animals, we derive the steady-state utilization distribution in a closed analytic form. Second, we give a recipe for deriving spatial pattern formation properties that emerge from interacting animals: specifically, do those interactions cause heterogeneous spatial distributions to emerge and if so, do these distributions oscillate at short times or emerge without oscillations? The second question is applied to data on concurrently tracked bank volesMyodes glareolus. Our results show that SSA can accurately parametrize diffusion-taxis equations from location data, providing the frequency of the data is not too low. We show that the steady-state distribution of our diffusion-taxis model, where it is derived, has an identical functional form to the utilization distribution given by resource selection analysis (RSA), thus formally linking (fine scale) SSA with (broad scale) RSA. For the bank vole data, we show how our SSA-PDE approach can give predictions regarding the spatial aggregation and segregation of different individuals, which are difficult to predict purely by examining results of SSA. Our methods provide a user-friendly way into the world of PDEs, via a well-used statistical technique, which should lead to tighter links between the findings of mathematical ecology and observations from empirical ecology. By providing a non-speculative link between observed movement behaviours and space use patterns on larger spatio-temporal scales, our findings will also aid integration of movement ecology into understanding spatial species distributions.},
  language  = {en}
}
@article{SchirmerHoffmannEccardetal.2020,
  author    = {Schirmer, Annika and Hoffmann, Julia and Eccard, Jana and Dammhahn, Melanie},
  title     = {My niche},
  series = {Proceedings of the Royal Society of London : B, Biological sciences},
  volume    = {287},
  journal   = {Proceedings of the Royal Society of London : B, Biological sciences},
  number    = {1918},
  publisher = {Royal Society},
  address   = {London},
  issn      = {0962-8452},
  doi       = {10.1098/rspb.2019.2211},
  pages     = {9},
  year      = {2020},
  abstract  = {Intraspecific trait variation is an important determinant of fundamental ecological interactions. Many of these interactions are mediated by behaviour. Therefore, interindividual differences in behaviour should contribute to individual niche specialization. Comparable with variation in morphological traits, behavioural differentiation between individuals should limit similarity among competitors and thus act as a mechanism maintaining within-species variation in ecological niches and facilitating species coexistence. Here, we aimed to test whether interindividual differences in boldness covary with spatial interactions within and between two ecologically similar, co-occurring rodent species (Myodes glareolus, Apodemus agrarius). In five subpopulations in northeast Germany, we quantified individual differences in boldness via repeated standardized tests and spatial interaction patterns via capture-mark- recapture (n = 126) and automated VHF telemetry (n = 36). We found that boldness varied with space use in both species. Individuals of the same population occupied different spatial niches, which resulted in non-random patterns of within- and between-species spatial interactions. Behavioural types mainly differed in the relative importance of intra- versus interspecific competition. Within-species variation along this competition gradient could contribute to maintaining individual niche specialization. Moreover, behavioural differentiation between individuals limits similarity among competitors, which might facilitate the coexistence of functionally equivalent species and, thus, affect community dynamics and local biodiversity.},
  language  = {en}
}
@phdthesis{Schaefer2019,
  author    = {Sch{\"a}fer, Merlin},
  title     = {Understanding and predicting global change impacts on migratory birds},
  doi       = {10.25932/publishup-43925},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-439256},
  school      = {Universit{\"a}t Potsdam},
  pages     = {XIV, 153},
  year      = {2019},
  abstract  = {This is a publication-based dissertation comprising three original research stud-ies (one published, one submitted and one ready for submission; status March 2019). The dissertation introduces a generic computer model as a tool to investigate the behaviour and population dynamics of animals in cyclic environments. The model is further employed for analysing how migratory birds respond to various scenarios of altered food supply under global change. Here, ecological and evolutionary time-scales are considered, as well as the biological constraints and trade-offs the individual faces, which ultimately shape response dynamics at the population level. Further, the effect of fine-scale temporal patterns in re-source supply are studied, which is challenging to achieve experimentally. My findings predict population declines, altered behavioural timing and negative carry-over effects arising in migratory birds under global change. They thus stress the need for intensified research on how ecological mechanisms are affected by global change and for effective conservation measures for migratory birds. The open-source modelling software created for this dissertation can now be used for other taxa and related research questions. Overall, this thesis improves our mechanistic understanding of the impacts of global change on migratory birds as one prerequisite to comprehend ongoing global biodiversity loss. The research results are discussed in a broader ecological and scientific context in a concluding synthesis chapter.},
  language  = {en}
}
@phdthesis{Scherer2019,
  author    = {Scherer, Philipp C{\´e}dric},
  title     = {Infection on the move},
  school      = {Universit{\"a}t Potsdam},
  pages     = {x, 107, XXXVIII},
  year      = {2019},
  abstract  = {Movement plays a major role in shaping population densities and contact rates among individuals, two factors that are particularly relevant for disease outbreaks. Although any differences in movement behaviour due to individual characteristics of the host and heterogeneity in landscape structure are likely to have considerable consequences for disease dynamics, these mechanisms are neglected in most epidemiological studies. Therefore, developing a general understanding how the interaction of movement behaviour and spatial heterogeneity shapes host densities, contact rates and ultimately pathogen spread is a key question in ecological and epidemiological research. In my thesis, I address this gap using both theoretical and empirical modelling approaches. In the theoretical part of my thesis, I investigated bottom-up effects of individual movement behaviour and landscape structure on host density, contact rates, and ultimately disease dynamics. I extended an established agent-based model that simulates ecological and epidemiological key processes to incorporate explicit movement of host individuals and landscape complexity. Neutral landscape models are a powerful basis for spatially-explicit modelling studies to imitate the complex characteristics of natural landscapes. In chapter 2, the first study of my thesis, I introduce two complementary R packages, NLMR and landscapetools, that I have co-developed to simplify the workflow of simulation and customization of such landscapes. To demonstrate the use of the packages I present a case study using the spatially explicit eco-epidemiological model and show that landscape complexity per se increases the probability of disease persistence. By using simple rules to simulate explicit host movement, I highlight in chapter 3 how disease dynamics are affected by population-level properties emerging from different movement rules leading to differences in the realized movement distance, spatiotemporal host density, and heterogeneity in transmission rates. As a consequence, mechanistic movement decisions based on the underlying landscape or conspecific competition led to considerably higher probabilities than phenomenological random walk approaches due directed movement leading to spatiotemporal differences in host densities. The results of these two chapters highlight the need to explicitly consider spatial heterogeneity and host movement behaviour when theoretical approaches are used to assess control measures to prevent outbreaks or eradicate diseases. In the empirical part of my thesis (chapter 4), I focus on the spatiotemporal dynamics of Classical Swine Fever in a wild boar population by analysing epidemiological data that was collected during an outbreak in Northern Germany persisting for eight years. I show that infection risk exhibits different seasonal patterns on the individual and the regional level. These patterns on the one hand show a higher infection risk in autumn and winter that may arise due to onset of mating behaviour and hunting intensity, which result in increased movement ranges. On the other hand, the increased infection risk of piglets, especially during the birth season, indicates the importance of new susceptible host individuals for local pathogen spread. The findings of this chapter underline the importance of different spatial and temporal scales to understand different components of pathogen spread that can have important implications for disease management. Taken together, the complementary use of theoretical and empirical modelling in my thesis highlights that our inferences about disease dynamics depend heavily on the spatial and temporal resolution used and how the inclusion of explicit mechanisms underlying hosts movement are modelled. My findings are an important step towards the incorporation of spatial heterogeneity and a mechanism-based perspective in eco-epidemiological approaches. This will ultimately lead to an enhanced understanding of the feedbacks of contact rates on pathogen spread and disease persistence that are of paramount importance to improve predictive models at the interface of ecology and epidemiology.},
  language  = {en}
}
@phdthesis{Schirmer2019,
  author    = {Schirmer, Annika},
  title     = {Consistent individual differences in movement-related behaviour as equalising and/or stabilising mechanisms for species coexistence},
  school      = {Universit{\"a}t Potsdam},
  pages     = {154},
  year      = {2019},
  abstract  = {The facilitation of species coexistence has been a central theme in ecological research for years, highlighting two key aspects: ecological niches and competition between species. According to the competitive exclusion principle, the overlap of species niches predicts the amount of shared resources and therefore competition between species, determining their ability to coexist. Only if niches of two species are sufficiently different, thus niche overlap is low, competition within species is higher than competition between species and stable coexistence is possible. Thereby, differences in species mean traits are focused on and conspecific individuals are assumed to be interchangeable. This approach might be outdated since behaviour, as a key aspect mediating niche differentiation between species, is individual based. Individuals from one species consistently differ across time and situations in their behavioural traits. Causes and consequences of consistent behavioural differences have been thoroughly investigated stimulating their recent incorporation into ecological interactions and niche theory. Spatial components have so far been largely overlooked, although animal movement is strongly connected to several aspects of ecological niches and interactions between individuals. Furthermore, numerous movement aspects haven been proven to be crucially influenced by consistent individual differences. Considering spatial parameters could therefore crucially broaden our understanding of how individual niches are formed and ecological interactions are shaped. Furthermore, extending established concepts on species interactions by an individual component could provide new insights into how species coexistence is facilitated and local biodiversity is maintained. The main aim of this thesis was to test whether consistent inter-individual differences can facilitate the coexistence of ecological similar species. Therefore, the effects of consistent inter-individual differences on the spatial behaviour of two rodent species, the bank vole (Myodes glareolus) and the striped field mouse (Apodemus agrarius), were investigated and put in the context of: (i) individual spatial niches, (ii) interactions between species, and (iii) the importance of different levels of behavioural variation within species for their interactions. Consistent differences of study animals in boldness and exploration were quantified with the same tests in all presented studies and always combined with observations of movement and space use via automated VHF radio telemetry. Consequently, results are comparable throughout the thesis and the methods provide a common denominator for all chapters. The first two chapters are based on observations of free-ranging rodents in natural populations, while chapter III represents an experimental approach under semi-natural conditions. Chapter I focusses on the effect of consistent differences in boldness and exploration on movement and space use of bank voles and their contribution to individual spatial niche separation. Results show boldness to be the dominating predictor for spatial parameters in bank voles. Irrespective of sex, bolder individuals had larger home ranges, moved longer distances, had less spatial interactions with conspecifics and occupied different microhabitats compared to shy individuals. The same boldness-dependent spatial patterns could be observed in striped field mice which is reported in chapter II. Therefore, both study species showed individual spatial niche occupation. Chapter II builds on findings from the first chapter, investigating the effect of boldness driven individual spatial niche occupation on the interactions between species. Irrespective of species and sex, bolder individuals had more interspecific spatial interactions, but less intraspecific interactions, compared to shy individuals. Due to individual niches occupation the competitive environment individuals experience is not random. Interactions are restricted to individuals of similar behavioural type with presumably similar competitive ability, which could balance differences on the species level and support coexistence. In chapter III the experimental populations were either comprised of only shy or only bold bank voles, while striped field mice varied, creating either a shy- or bold-biased competitive community. Irrespective of behavioural type, striped field mice had more intraspecific interactions in bold-biased competitive communities. Only in a shy-biased competitive community, bolder striped field mice had less interspecific interactions compared to shy individuals. Bank voles showed no difference in intra- or interspecific interactions between populations. Chapter III highlights, that not only consistent inter-individual differences per se are important for interactions within and between species, but also the amount of behavioural variation within coexisting species. Overall, this thesis highlights the importance of considering consistent inter-individual differences in a spatial context and their connection to individual spatial niche occupation, as well as the resulting effects on interactions within and between species. Individual differences are discussed in the context of similarity of individuals, individual and species niche width, and individual and species niche overlap. Thereby, this thesis makes one step further from the existing research on individual niches towards integrating consistent inter-individual differences into the larger framework of species coexistence.},
  language  = {en}
}
@article{SchlaegelMerrillLewis2017,
  author    = {Schl{\"a}gel, Ulrike E. and Merrill, Evelyn H. and Lewis, Mark A.},
  title     = {Territory surveillance and prey management: Wolves keep track of space and time},
  series = {Ecology and evolution},
  volume    = {7},
  journal   = {Ecology and evolution},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {2045-7758},
  doi       = {10.1002/ece3.3176},
  pages     = {8388 -- 8405},
  year      = {2017},
  abstract  = {Identifying behavioral mechanisms that underlie observed movement patterns is difficult when animals employ sophisticated cognitive\&\#8208;based strategies. Such strategies may arise when timing of return visits is important, for instance to allow for resource renewal or territorial patrolling. We fitted spatially explicit random\&\#8208;walk models to GPS movement data of six wolves (Canis lupus; Linnaeus, 1758) from Alberta, Canada to investigate the importance of the following: (1) territorial surveillance likely related to renewal of scent marks along territorial edges, to reduce intraspecific risk among packs, and (2) delay in return to recently hunted areas, which may be related to anti\&\#8208;predator responses of prey under varying prey densities. The movement models incorporated the spatiotemporal variable "time since last visit," which acts as a wolf's memory index of its travel history and is integrated into the movement decision along with its position in relation to territory boundaries and information on local prey densities. We used a model selection framework to test hypotheses about the combined importance of these variables in wolf movement strategies. Time\&\#8208;dependent movement for territory surveillance was supported by all wolf movement tracks. Wolves generally avoided territory edges, but this avoidance was reduced as time since last visit increased. Time\&\#8208;dependent prey management was weak except in one wolf. This wolf selected locations with longer time since last visit and lower prey density, which led to a longer delay in revisiting high prey density sites. Our study shows that we can use spatially explicit random walks to identify behavioral strategies that merge environmental information and explicit spatiotemporal information on past movements (i.e., "when" and "where") to make movement decisions. The approach allows us to better understand cognition\&\#8208;based movement in relation to dynamic environments and resources.},
  language  = {en}
}