TY - THES A1 - Stiegler, Jonas T1 - Mobile link functions in unpredictable agricultural landscapes N2 - 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. N2 - Die Bewegung von Tieren ist ein entscheidender Aspekt des Lebens, der ökologische und evolutionäre Prozesse beeinflusst. Sie spielt eine wichtige Rolle bei der Gestaltung der biologischen Vielfalt und verbindet Lebensräume und Ökosysteme miteinander. Anthropogene Landschaftsveränderungen, z.B. in der Landwirtschaft, können die Bewegung von Tieren behindern, indem sie ihre Fähigkeiten beeinträchtigen, Ressourcen innerhalb ihres täglichen Bewegungsradius zu lokalisieren und im größeren Maßstab, ihre Wanderung oder Ausbreitung limitieren. In dieser Thesis untersuche ich die Bewegungsmerkmale und Aktivitätsmuster des Feldhasen (Lepus europaeus), um seine Bedeutung als Schlüsselart in fragmentierten Agrarlandschaften zu verstehen. Ich lege faszinierende Ergebnisse vor, die die Bedeutung des Hasen für die Verbreitung von Saatgut, den Einfluss von Persönlichkeitsmerkmalen auf das Verhalten und die Raumnutzung, die Sensibilität des Hasen gegenüber extremen Witterungsbedingungen und die Auswirkungen von GPS-Empfängern auf die Aktivitätsmuster und das Bewegungsverhalten der Säugetiere beleuchten. In Kapitel I führte ich ein kontrolliertes Fütterungsexperiment durch, um den potenziellen Einfluss von Hasen auf die Samenausbreitung zu analysieren. Durch die zusätzliche Verwendung von GPS-Daten von Hasen in zwei kontrastierenden Landschaften konnte ich nachweisen, dass Hasen eine wichtige Rolle spielen, da sie in kleinen und isolierten Habitatfeldern als effektive mobile Verbindungsglieder für viele Pflanzenarten fungieren. Die Analyse der Samenaufnahme und des Keimungserfolgs zeigte, dass verschiedene Eigenschaften der Samen, wie Dichte, Oberfläche und Form, die Fähigkeit der Hasen, Samen durch Endozoochorie zu verbreiten, stark beeinflussen. Diese Ergebnisse verdeutlichen die Wechselwirkung zwischen Hasen und Pflanzengemeinschaften und liefern somit wertvolle Erkenntnisse über die Mechanismen der Samenverbreitung in fragmentierten Landschaften. Durch den Einsatz standardisierter Verhaltenstests in Kapitel II konnte ich konsistente Verhaltensreaktionen bei in Gefangenschaft lebenden Hasen aufdecken und zeitgleich den komplexen Zusammenhang zwischen Persönlichkeitsmerkmalen und räumlichen Mustern in Wildhasenpopulationen untersuchen. Diese Analyse bietet Einblicke in die ökologischen Interaktionen und die Dynamik von Hasenpopulationen in landwirtschaftlichen Lebensräumen. Indem ich das Konzept der Tierpersönlichkeit untersuchte, stellte ich eine Verbindung zwischen Persönlichkeitsmerkmalen und dem Verhalten von Hasen her. Ich habe gezeigt, dass die durch standardisierte Tests gemessene Kühnheit den individuellen Erkundungsstil beeinflusst, wobei schüchterne und kühne Hasen unterschiedliche Raumnutzungsmuster aufweisen. Meine Forschung liefert nicht nur wertvolle Einblicke in die Rolle der Tierpersönlichkeit in heterogenen Umgebungen, sondern stellt auch einen neuartigen Ansatz vor, der die Durchführbarkeit einer Fernbeurteilung von Persönlichkeitstypen mithilfe von am Tier angebrachten Sensoren ohne zusätzliche Störung des Zielindividuums demonstrierte. Da die Klimabedingungen die Aktivität und folglich die Fitness von Wildtierarten auf der ganzen Welt stark beeinflussen, habe ich in Kapitel III die Sensibilität von Hasen gegenüber Temperatur, Luftfeuchtigkeit und Windgeschwindigkeit während ihrer Hauptfortpflanzungszeit ermittelt. Ich stellte fest, dass die Aktivität stark auf hohe Temperaturen über 25 °C reagiert, wobei die Auswirkungen bei extremen Temperaturen von über 35 °C besonders ausgeprägt sind. Die nicht lineare Beziehung zwischen Temperatur und Aktivität war durch gegensätzliche Reaktionen bei Tag und Nacht gekennzeichnet. Diese Ergebnisse unterstreichen die Anfälligkeit der Hasen für den Klimawandel und die möglichen Folgen für ihre Fitness und Populationsdynamik bei einem anhaltenden Temperaturanstieg. Da solche Erkenntnisse nur durch Fangen und Besendern von Wildtieren ermöglicht werden können, habe ich in Kapitel IV die potenziellen negativen Auswirkungen auf das Individuuum, sowie den Erholungsprozess nach dem Anlegen des Halsbandes untersucht. Hierfür analysierte ich die zurückgelegten täglichen Entfernungen in Verbindung mit der Aktivität von 1451 terrestrischen Säugetieren aus 42 verschiedenen Arten während ihrer anfänglichen Verfolgung. Die Intensität der Störung sowie die Geschwindigkeit der Erholung variieren je nach Art, wobei Pflanzenfresser, Weibchen und Individuen, die in relativ abgelegenen Untersuchungsgebieten gefangen und mit Halsbändern versehen wurden, aufgrund bisher begrenzter anthropogener Einflüsse stärkere Störungen erfahren. Mobile Verbindungsglieder sind essentiell für die Erhaltung der Biodiversität, indem sie eine wichtige Rolle in der Dynamik und Resilienz von Ökosystemen spielen. Weiterhin macht ihre Fähigkeit, sich durch zerstückelte Landschaften zu bewegen sie zu wichtigen Schlüsselkomponenten bei der Wiederherstellung von zerstörten Landschaften. Individuelle Bewegungsentscheidungen bestimmen den Maßstab der mobilen Verbindungen und die Schwankungen der Raumnutzung unter Individuen zu verstehen ist unerlässlich, um deren Funktion zu interpretieren. Der Klimawandel stellt eine weitere Herausforderung dar, indem Wildtiere dazu gezwungen werden, sich zu adaptieren, insbesondere an Hochtemperatur-Extreme. Den anthropogenen Einfluss auf Tierbewegungen aufzudecken bleibt von größter Bedeutung in der Landnutzungsplanung und die Entwicklung von erfolgreichen Strategien zum Schutz der Natur. Diese Thesis liefert ein umfassendes ökologisches Verständnis von Feldhasen in Agrarlandschaften. Die Ergebnisse meiner Forschung unterstreichen die Bedeutung von Hasen als mobile Bindeglieder, den Einfluss von Persönlichkeitsmerkmalen auf Verhalten und räumliche Muster, die Anfälligkeit von Hasen gegenüber extremen Wetterbedingungen und die unmittelbaren Folgen der Halsbandanbringung auf Tierbewegungen. Damit leiste ich einen wertvollen Beitrag zum Schutz und zur Bewirtschaftung von Wildtieren, indem ich die Entwicklung von Strategien zur Abschwächung der Auswirkungen von Umweltveränderungen auf Hasenpopulationen unterstütze. Darüber hinaus ermöglichen diese Erkenntnisse die Entwicklung von Methoden, die darauf abzielen, die Folgen der Halsbandanbringung zu minimieren und gleichzeitig potenzielle Verzerrungen in den Daten zu identifizieren, was sowohl dem Tierschutz als auch der wissenschaftlichen Integrität von Lokalisierungsstudien zugutekommt. KW - European hare KW - mammals KW - ecology KW - animal personality KW - seed dispersal KW - movement ecology KW - tracking impacts KW - energy budget KW - climate change KW - accelerometry KW - GPS KW - tracking KW - Feldhase KW - GPS KW - Beschleunigungsmessungen KW - Tierpersönlichkeit KW - Klimawandel KW - Tierökologie KW - Energiebudget KW - Säugetiere KW - Bewegungsökologie KW - Samenausbreitung KW - Tierortung KW - Konsequenzen von Fang und Besenderung Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-622023 ER - TY - JOUR A1 - Hoffmann, Julia A1 - Hölker, Franz A1 - Eccard, Jana T1 - Welcome to the dark side BT - partial nighttime illumination affects night-and daytime foraging behavior of a small mammal JF - Frontiers in ecology and evolution N2 - Differences in natural light conditions caused by changes in moonlight are known to affect perceived predation risk in many nocturnal prey species. As artificial light at night (ALAN) is steadily increasing in space and intensity, it has the potential to change movement and foraging behavior of many species as it might increase perceived predation risk and mask natural light cycles. We investigated if partial nighttime illumination leads to changes in foraging behavior during the night and the subsequent day in a small mammal and whether these changes are related to animal personalities. We subjected bank voles to partial nighttime illumination in a foraging landscape under laboratory conditions and in large grassland enclosures under near natural conditions. We measured giving-up density of food in illuminated and dark artificial seed patches and video recorded the movement of animals. While animals reduced number of visits to illuminated seed patches at night, they increased visits to these patches at the following day compared to dark seed patches. Overall, bold individuals had lower giving-up densities than shy individuals but this difference increased at day in formerly illuminated seed patches. Small mammals thus showed carry-over effects on daytime foraging behavior due to ALAN, i.e., nocturnal illumination has the potential to affect intra- and interspecific interactions during both night and day with possible changes in personality structure within populations and altered predator-prey dynamics. KW - light pollution KW - inter-individual differences KW - animal personality KW - Myodes glareolus KW - ALAN Y1 - 2022 U6 - https://doi.org/10.3389/fevo.2021.779825 SN - 2296-701X VL - 9 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Mazza, Valeria A1 - Günther, Anja T1 - City mice and country mice BT - innovative problem solving in rural and urban noncommensal rodents JF - Animal behaviour N2 - The ability to produce innovative behaviour is a key determinant in the successful coping with environmental challenges and changes. The expansion of human-altered environments presents wildlife with multiple novel situations in which innovativeness could be beneficial. A better understanding of the drivers of within-species variation in innovation propensity and its consequences will provide insights into the traits enabling animals to thrive in the face of human-induced rapid environmental change. We compared problem-solving performance of 31 striped field mice, Apodemus agrarius, originating from rural or urban environments in a battery of eight foraging extraction tasks. We tested whether differences in problem-solving performance were mediated by the extent and duration of the animal's exploration of the experimental set-ups, the time required to solve the tasks, and their persistence. In addition, we tested the influence of the diversity of motor responses, as well as of behavioural traits boldness and activity on problem-solving performance. Urban individuals were better problem solvers despite rural individuals approaching faster and interacting longer with the test set-ups. Participation rates and time required to solve a task did not differ between rural and urban individuals. However, in case of failure to solve a task, rural mice were more persistent. The best predictors of solving success, aside from the area of origin, were the time spent exploring the set-ups and boldness, while activity and diversity of motor responses did not explain it. Problem-solving ability could thus be a contributing factor to the successful coping with the rapid and recent expansion of human-altered environments. KW - animal personality KW - anthropogenic environment KW - Apodemus agrarius KW - HIREC KW - individual differences KW - innovation KW - problem solving KW - rodent KW - urbanization Y1 - 2021 U6 - https://doi.org/10.1016/j.anbehav.2020.12.007 SN - 0003-3472 SN - 1095-8282 VL - 172 SP - 197 EP - 210 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Schirmer, Annika A1 - Hoffmann, Julia A1 - Eccard, Jana A1 - Dammhahn, Melanie T1 - My niche BT - individual spatial niche specialization affects within- and between-species interactions JF - Proceedings of the Royal Society of London : B, Biological sciences N2 - 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. KW - animal personality KW - competition KW - individual niche specialization KW - movement ecology KW - coexistence KW - small mammals Y1 - 2020 U6 - https://doi.org/10.1098/rspb.2019.2211 SN - 0962-8452 SN - 1471-2954 VL - 287 IS - 1918 PB - Royal Society CY - London ER - TY - JOUR A1 - Steinhoff, Philip O. M. A1 - Warfen, Bennet A1 - Voigt, Sissy A1 - Uhl, Gabriele A1 - Dammhahn, Melanie T1 - Individual differences in risk-taking affect foraging across different landscapes of fear JF - Oikos N2 - One of the strongest determinants of behavioural variation is the tradeoff between resource gain and safety. Although classical theory predicts optimal foraging under risk, empirical studies report large unexplained variation in behaviour. Intrinsic individual differences in risk-taking behaviour might contribute to this variation. By repeatedly exposing individuals of a small mesopredator to different experimental landscapes of risks and resources, we tested 1) whether individuals adjust their foraging behaviour according to predictions of the general tradeoff between energy gain and predation avoidance and 2) whether individuals differ consistently and predictably from each other in how they solve this tradeoff. Wild-caught individuals (n = 42) of the jumping spiderMarpissa muscosa, were subjected to repeated release and open-field tests to quantify among-individual variation in boldness and activity. Subsequently, individuals were tested in four foraging tests that differed in risk level (white/dark background colour) and risk variation (constant risk/variable risk simulated by bird dummy overflights) and contained inaccessible but visually perceivable food patches. When exposed to a white background, individuals reduced some aspects of movement and foraging intensity, suggesting that the degree of camouflage serves as a proxy of perceived risk in these predators. Short pulses of acute predation risk, simulated by bird overflights, had only small effects on aspects of foraging behaviour. Notably, a significant part of variation in foraging was due to among-individual differences across risk landscapes that are linked to consistent individual variation in activity, forming a behavioural syndrome. Our results demonstrate the importance of among-individual differences in behaviour of animals that forage under different levels of perceived risk. Since these differences likely affect food-web dynamics and have fitness consequences, future studies should explore the mechanisms that maintain the observed variation in natural populations. KW - animal personality KW - behavioural syndrome KW - foraging KW - jumping spider KW - landscape of fear KW - risk-reward tradeoff Y1 - 2020 U6 - https://doi.org/10.1111/oik.07508 SN - 0030-1299 SN - 1600-0706 VL - 129 IS - 12 SP - 1891 EP - 1902 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Eccard, Jana A1 - Liesenjohann, Thilo A1 - Dammhahn, Melanie T1 - Among-individual differences in foraging modulate resource exploitation under perceived predation risk JF - Oecologia N2 - Foraging is risky and involves balancing the benefits of resource acquisition with costs of predation. Optimal foraging theory predicts where, when and how long to forage in a given spatiotemporal distribution of risks and resources. However, significant variation in foraging behaviour and resource exploitation remain unexplained. Using single foragers in artificial landscapes of perceived risks and resources with diminishing returns, we aimed to test whether foraging behaviour and resource exploitation are adjusted to risk level, vary with risk during different components of foraging, and (co)vary among individuals. We quantified foraging behaviour and resource exploitation for 21 common voles (Microtus arvalis). By manipulating ground cover, we created simple landscapes of two food patches varying in perceived risk during feeding in a patch and/or while travelling between patches. Foraging of individuals was variable and adjusted to risk level and type. High risk during feeding reduced feeding duration and food consumption more strongly than risk while travelling. Risk during travelling modified the risk effects of feeding for changes between patches and resulting evenness of resource exploitation. Across risk conditions individuals differed consistently in when and how long they exploited resources and exposed themselves to risk. These among-individual differences in foraging behaviour were associated with consistent patterns of resource exploitation. Thus, different strategies in foraging-under-risk ultimately lead to unequal payoffs and might affect lower trophic levels in food webs. Inter-individual differences in foraging behaviour, i.e. foraging personalities, are an integral part of foraging behaviour and need to be fully integrated into optimal foraging theory. KW - animal personality KW - giving-up density KW - intra-specific trait variation KW - landscape of fear KW - optimal foraging KW - predation risk KW - resource KW - exploitation Y1 - 2020 U6 - https://doi.org/10.1007/s00442-020-04773-y SN - 0029-8549 SN - 1432-1939 VL - 194 IS - 4 SP - 621 EP - 634 PB - Springer CY - Berlin ER - TY - JOUR A1 - Mazza, Valeria A1 - Dammhahn, Melanie A1 - Lösche, Elisa A1 - Eccard, Jana T1 - Small mammals in the big city BT - behavioural adjustments of non-commensal rodents to urban environments JF - Global change biology N2 - A fundamental focus of current ecological and evolutionary research is to illuminate the drivers of animals' success in coping with human-induced rapid environmental change (HIREC). Behavioural adaptations are likely to play a major role in coping with HIREC because behaviour largely determines how individuals interact with their surroundings. A substantial body of research reports behavioural modifications in urban dwellers compared to rural conspecifics. However, it is often unknown whether the observed phenotypic divergence is due to phenotypic plasticity or the product of genetic adaptations. Here, we aimed at investigating (a) whether behavioural differences arise also between rural and urban populations of non-commensal rodents; and (b) whether these differences result from behavioural flexibility or from intrinsic behavioural characteristics, such as genetic or maternal effects. We captured and kept under common environment conditions 42 rural and 52 urban adult common voles (Microtus arvalis) from seven subpopulations along a rural-urban gradient. We investigated individual variation in behavioural responses associated with risk-taking and exploration, in situ at the time of capture in the field and ex situ after 3 months in captivity. Urban dwellers were bolder and more explorative than rural conspecifics at the time of capture in their respective sites (in situ). However, when tested under common environmental conditions ex situ, rural individuals showed little change in their behavioural responses whereas urban individuals altered their behaviour considerably and were consistently shyer and less explorative than when tested in situ. The combination of elevated risk-taking and exploration with high behavioural flexibility might allow urban populations to successfully cope with the challenges of HIREC. Investigating whether the observed differences in behavioural flexibility are adaptive and how they are shaped by additive and interactive effects of genetic make-up and past environmental conditions will help illuminate eco-evolutionary dynamics under HIREC and predict persistence of populations under urban conditions. KW - animal personality KW - behavioural adjustment KW - behavioural flexibility KW - environmental change KW - HIREC KW - rodents KW - urbanization Y1 - 2020 U6 - https://doi.org/10.1111/gcb.15304 SN - 1354-1013 SN - 1365-2486 VL - 26 IS - 11 SP - 6326 EP - 6337 PB - Wiley CY - Hoboken ER - TY - GEN A1 - Eccard, Jana A1 - Herde, Antje A1 - Schuster, Andrea C. A1 - Liesenjohann, Thilo A1 - Knopp, Tatjana A1 - Heckel, Gerald A1 - Dammhahn, Melanie T1 - Fitness, risk taking, and spatial behavior covary with boldness in experimental vole populations T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Individuals of a population may vary along a pace-of-life syndrome from highly fecund, short-lived, bold, dispersive “fast” types at one end of the spectrum to less fecund, long-lived, shy, plastic “slow” types at the other end. Risk-taking behavior might mediate the underlying life history trade-off, but empirical evidence supporting this hypothesis is still ambiguous. Using experimentally created populations of common voles (Microtus arvalis)—a species with distinct seasonal life history trajectories—we aimed to test whether individual differences in boldness behavior covary with risk taking, space use, and fitness. We quantified risk taking, space use (via automated tracking), survival, and reproductive success (via genetic parentage analysis) in 8 to 14 experimental, mixed-sex populations of 113 common voles of known boldness type in large grassland enclosures over a significant part of their adult life span and two reproductive events. Populations were assorted to contain extreme boldness types (bold or shy) of both sexes. Bolder individuals took more risks than shyer ones, which did not affect survival. Bolder males but not females produced more offspring than shy conspecifics. Daily home range and core area sizes, based on 95% and 50% Kernel density estimates (20 ± 10 per individual, n = 54 individuals), were highly repeatable over time. Individual space use unfolded differently for sex-boldness type combinations over the course of the experiment. While day ranges decreased for shy females, they increased for bold females and all males. Space use trajectories may, hence, indicate differences in coping styles when confronted with a novel social and physical environment. Thus, interindividual differences in boldness predict risk taking under near-natural conditions and have consequences for fitness in males, which have a higher reproductive potential than females. Given extreme inter- and intra-annual fluctuations in population density in the study species and its short life span, density-dependent fluctuating selection operating differently on the sexes might maintain (co)variation in boldness, risk taking, and pace-of-life. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1258 KW - animal personality KW - automated radio telemetry KW - behavioral type KW - fitness KW - home range KW - Microtus arvalis KW - parentage KW - reproductive success Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-558866 SN - 1866-8372 SP - 1 EP - 15 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Eccard, Jana A1 - Herde, Antje A1 - Schuster, Andrea C. A1 - Liesenjohann, Thilo A1 - Knopp, Tatjana A1 - Heckel, Gerald A1 - Dammhahn, Melanie T1 - Fitness, risk taking, and spatial behavior covary with boldness in experimental vole populations JF - Ecology And Evolution N2 - Individuals of a population may vary along a pace-of-life syndrome from highly fecund, short-lived, bold, dispersive “fast” types at one end of the spectrum to less fecund, long-lived, shy, plastic “slow” types at the other end. Risk-taking behavior might mediate the underlying life history trade-off, but empirical evidence supporting this hypothesis is still ambiguous. Using experimentally created populations of common voles (Microtus arvalis)—a species with distinct seasonal life history trajectories—we aimed to test whether individual differences in boldness behavior covary with risk taking, space use, and fitness. We quantified risk taking, space use (via automated tracking), survival, and reproductive success (via genetic parentage analysis) in 8 to 14 experimental, mixed-sex populations of 113 common voles of known boldness type in large grassland enclosures over a significant part of their adult life span and two reproductive events. Populations were assorted to contain extreme boldness types (bold or shy) of both sexes. Bolder individuals took more risks than shyer ones, which did not affect survival. Bolder males but not females produced more offspring than shy conspecifics. Daily home range and core area sizes, based on 95% and 50% Kernel density estimates (20 ± 10 per individual, n = 54 individuals), were highly repeatable over time. Individual space use unfolded differently for sex-boldness type combinations over the course of the experiment. While day ranges decreased for shy females, they increased for bold females and all males. Space use trajectories may, hence, indicate differences in coping styles when confronted with a novel social and physical environment. Thus, interindividual differences in boldness predict risk taking under near-natural conditions and have consequences for fitness in males, which have a higher reproductive potential than females. Given extreme inter- and intra-annual fluctuations in population density in the study species and its short life span, density-dependent fluctuating selection operating differently on the sexes might maintain (co)variation in boldness, risk taking, and pace-of-life. KW - animal personality KW - automated radio telemetry KW - behavioral type KW - fitness KW - home range KW - Microtus arvalis KW - parentage KW - reproductive success Y1 - 2022 U6 - https://doi.org/10.1002/ece3.8521 SN - 2045-7758 SP - 1 EP - 15 PB - John Wiley & Sons, Inc. CY - Vereinigte Staaten ER - TY - GEN A1 - Hoffmann, Julia A1 - Hölker, Franz A1 - Eccard, Jana T1 - Welcome to the Dark Side BT - Partial Nighttime Illumination Affects Night-and Daytime Foraging Behavior of a Small Mammal T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Differences in natural light conditions caused by changes in moonlight are known to affect perceived predation risk in many nocturnal prey species. As artificial light at night (ALAN) is steadily increasing in space and intensity, it has the potential to change movement and foraging behavior of many species as it might increase perceived predation risk and mask natural light cycles. We investigated if partial nighttime illumination leads to changes in foraging behavior during the night and the subsequent day in a small mammal and whether these changes are related to animal personalities. We subjected bank voles to partial nighttime illumination in a foraging landscape under laboratory conditions and in large grassland enclosures under near natural conditions. We measured giving-up density of food in illuminated and dark artificial seed patches and video recorded the movement of animals. While animals reduced number of visits to illuminated seed patches at night, they increased visits to these patches at the following day compared to dark seed patches. Overall, bold individuals had lower giving-up densities than shy individuals but this difference increased at day in formerly illuminated seed patches. Small mammals thus showed carry-over effects on daytime foraging behavior due to ALAN, i.e., nocturnal illumination has the potential to affect intra- and interspecific interactions during both night and day with possible changes in personality structure within populations and altered predator-prey dynamics. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1231 KW - light pollution KW - inter-individual differences KW - animal personality KW - Myodes glareolus KW - ALAN Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-544702 SN - 1866-8372 ER - TY - JOUR A1 - Hoffmann, Julia A1 - Hölker, Franz A1 - Eccard, Jana T1 - Welcome to the Dark Side BT - Partial Nighttime Illumination Affects Night-and Daytime Foraging Behavior of a Small Mammal JF - Frontiers in Ecology and Evolution N2 - Differences in natural light conditions caused by changes in moonlight are known to affect perceived predation risk in many nocturnal prey species. As artificial light at night (ALAN) is steadily increasing in space and intensity, it has the potential to change movement and foraging behavior of many species as it might increase perceived predation risk and mask natural light cycles. We investigated if partial nighttime illumination leads to changes in foraging behavior during the night and the subsequent day in a small mammal and whether these changes are related to animal personalities. We subjected bank voles to partial nighttime illumination in a foraging landscape under laboratory conditions and in large grassland enclosures under near natural conditions. We measured giving-up density of food in illuminated and dark artificial seed patches and video recorded the movement of animals. While animals reduced number of visits to illuminated seed patches at night, they increased visits to these patches at the following day compared to dark seed patches. Overall, bold individuals had lower giving-up densities than shy individuals but this difference increased at day in formerly illuminated seed patches. Small mammals thus showed carry-over effects on daytime foraging behavior due to ALAN, i.e., nocturnal illumination has the potential to affect intra- and interspecific interactions during both night and day with possible changes in personality structure within populations and altered predator-prey dynamics. KW - light pollution KW - inter-individual differences KW - animal personality KW - Myodes glareolus KW - ALAN Y1 - 2021 U6 - https://doi.org/10.3389/fevo.2021.779825 SN - 2296-701X VL - 9 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Mazza, Valeria A1 - Eccard, Jana A1 - Zaccaroni, Marco A1 - Jacob, Jens A1 - Dammhahn, Melanie T1 - The fast and the flexible BT - cognitive style drives individual variation in cognition in a small mammal JF - Animal behaviour KW - animal personality KW - associative learning KW - behavioural syndrome KW - fast and slow learner KW - individual differences KW - Myodes glareolus KW - rodent KW - speed-accuracy trade-off KW - temperament Y1 - 2018 U6 - https://doi.org/10.1016/j.anbehav.2018.01.011 SN - 0003-3472 SN - 1095-8282 VL - 137 SP - 119 EP - 132 PB - Elsevier CY - London ER - TY - JOUR A1 - Dammhahn, Melanie A1 - Mazza, Valeria A1 - Schirmer, Annika A1 - Göttsche, Claudia A1 - Eccard, Jana T1 - Of city and village mice BT - behavioural adjustments of striped field mice to urban environments JF - Scientific Reports N2 - A fundamental question of current ecological research concerns the drives and limits of species responses to human-induced rapid environmental change (HIREC). Behavioural responses to HIREC are a key component because behaviour links individual responses to population and community changes. Ongoing fast urbanization provides an ideal setting to test the functional role of behaviour for responses to HIREC. Consistent behavioural differences between conspecifics (animal personality) may be important determinants or constraints of animals’ adaptation to urban habitats. We tested whether urban and rural populations of small mammals differ in mean trait expression, flexibility and repeatability of behaviours associated to risk-taking and exploratory tendencies. Using a standardized behavioural test in the field, we quantified spatial exploration and boldness of striped field mice (Apodemus agrarius, n = 96) from nine sub-populations, presenting different levels of urbanisation and anthropogenic disturbance. The level of urbanisation positively correlated with boldness, spatial exploration and behavioural flexibility, with urban dwellers being bolder, more explorative and more flexible in some traits than rural conspecifics. Thus, individuals seem to distribute in a non-random way in response to human disturbance based on their behavioural characteristics. Animal personality might therefore play a key role in successful coping with the challenges of HIREC. KW - personality-traits KW - apodemus-agrarius KW - exploratory-behavior KW - fitness consequences KW - individual variation KW - avian personalities KW - animal personality KW - rural populations KW - natural-selection KW - natal dispersal Y1 - 2020 U6 - https://doi.org/10.1038/s41598-020-69998-6 SN - 2045-2322 VL - 10 PB - Macmillan Publishers Limited CY - London ER - TY - GEN A1 - Dammhahn, Melanie A1 - Mazza, Valeria A1 - Schirmer, Annika A1 - Göttsche, Claudia A1 - Eccard, Jana T1 - Of city and village mice BT - behavioural adjustments of striped field mice to urban environments T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - A fundamental question of current ecological research concerns the drives and limits of species responses to human-induced rapid environmental change (HIREC). Behavioural responses to HIREC are a key component because behaviour links individual responses to population and community changes. Ongoing fast urbanization provides an ideal setting to test the functional role of behaviour for responses to HIREC. Consistent behavioural differences between conspecifics (animal personality) may be important determinants or constraints of animals’ adaptation to urban habitats. We tested whether urban and rural populations of small mammals differ in mean trait expression, flexibility and repeatability of behaviours associated to risk-taking and exploratory tendencies. Using a standardized behavioural test in the field, we quantified spatial exploration and boldness of striped field mice (Apodemus agrarius, n = 96) from nine sub-populations, presenting different levels of urbanisation and anthropogenic disturbance. The level of urbanisation positively correlated with boldness, spatial exploration and behavioural flexibility, with urban dwellers being bolder, more explorative and more flexible in some traits than rural conspecifics. Thus, individuals seem to distribute in a non-random way in response to human disturbance based on their behavioural characteristics. Animal personality might therefore play a key role in successful coping with the challenges of HIREC. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1007 KW - personality-traits KW - apodemus-agrarius KW - exploratory-behavior KW - fitness consequences KW - individual variation KW - avian personalities KW - animal personality KW - rural populations KW - natural-selection KW - natal dispersal Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-480063 SN - 1866-8372 IS - 1007 ER - TY - JOUR A1 - Mazza, Valeria A1 - Jacob, Jens A1 - Dammhahn, Melanie A1 - Zaccaroni, Marco A1 - Eccard, Jana T1 - Individual variation in cognitive style reflects foraging and antipredator strategies in a small mammal JF - Scientific Reports N2 - Balancing foraging gain and predation risk is a fundamental trade-off in the life of animals. Individual strategies to acquire, process, store and use information to solve cognitive tasks are likely to affect speed and flexibility of learning, and ecologically relevant decisions regarding foraging and predation risk. Theory suggests a functional link between individual variation in cognitive style and behaviour (animal personality) via speed-accuracy and risk-reward trade-offs. We tested whether cognitive style and personality affect risk-reward trade-off decisions posed by foraging and predation risk. We exposed 21 bank voles (Myodes glareolus) that were bold, fast learning and inflexible and 18 voles that were shy, slow learning and flexible to outdoor enclosures with different risk levels at two food patches. We quantified individual food patch exploitation, foraging and vigilance behaviour. Although both types responded to risk, fast animals increasingly exploited both food patches, gaining access to more food and spending less time searching and exercising vigilance. Slow animals progressively avoided high-risk areas, concentrating foraging effort in the low-risk one, and devoting >50% of visit to vigilance. These patterns indicate that individual differences in cognitive style/personality are reflected in foraging and anti-predator decisions that underlie the individual risk-reward bias. KW - animal personality KW - bank voles KW - behavioral flexibility KW - coping styles KW - exploratory-behavior KW - mustelid predation KW - social information KW - stress KW - trade-offs KW - voles clethrionomys-glareolus Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-46582-1 SN - 2045-2322 VL - 9 PB - Macmillan Publishers Limited, part of Springer Nature CY - London ER - TY - GEN A1 - Mazza, Valeria A1 - Jacob, Jens A1 - Dammhahn, Melanie A1 - Zaccaroni, Marco A1 - Eccard, Jana T1 - Individual variation in cognitive style reflects foraging and antipredator strategies in a small mammal T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Balancing foraging gain and predation risk is a fundamental trade-off in the life of animals. Individual strategies to acquire, process, store and use information to solve cognitive tasks are likely to affect speed and flexibility of learning, and ecologically relevant decisions regarding foraging and predation risk. Theory suggests a functional link between individual variation in cognitive style and behaviour (animal personality) via speed-accuracy and risk-reward trade-offs. We tested whether cognitive style and personality affect risk-reward trade-off decisions posed by foraging and predation risk. We exposed 21 bank voles (Myodes glareolus) that were bold, fast learning and inflexible and 18 voles that were shy, slow learning and flexible to outdoor enclosures with different risk levels at two food patches. We quantified individual food patch exploitation, foraging and vigilance behaviour. Although both types responded to risk, fast animals increasingly exploited both food patches, gaining access to more food and spending less time searching and exercising vigilance. Slow animals progressively avoided high-risk areas, concentrating foraging effort in the low-risk one, and devoting >50% of visit to vigilance. These patterns indicate that individual differences in cognitive style/personality are reflected in foraging and anti-predator decisions that underlie the individual risk-reward bias. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 761 KW - voles clethrionomys-glareolus KW - coping styles KW - bank voles KW - behavioral flexibility KW - trade-offs KW - exploratory-behavior KW - mustelid predation KW - social information KW - animal personality KW - stress Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-437118 SN - 1866-8372 IS - 761 ER - TY - GEN A1 - Kowalski, Gabriele Joanna A1 - Grimm, Volker A1 - Herde, Antje A1 - Guenther, Anja A1 - Eccard, Jana T1 - Does Animal Personality Affect Movement in Habitat Corridors? BT - Experiments with Common Voles (Microtus arvalis) Using Different Corridor Widths T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Animal personality may affect an animal’s mobility in a given landscape, influencing its propensity to take risks in an unknown environment. We investigated the mobility of translocated common voles in two corridor systems 60 m in length and differing in width (1 m and 3 m). Voles were behaviorally phenotyped in repeated open field and barrier tests. Observed behavioral traits were highly repeatable and described by a continuous personality score. Subsequently, animals were tracked via an automated very high frequency (VHF) telemetry radio tracking system to monitor their movement patterns in the corridor system. Although personality did not explain movement patterns, corridor width determined the amount of time spent in the habitat corridor. Voles in the narrow corridor system entered the corridor faster and spent less time in the corridor than animals in the wide corridor. Thus, landscape features seem to affect movement patterns more strongly than personality. Meanwhile, site characteristics, such as corridor width, could prove to be highly important when designing corridors for conservation, with narrow corridors facilitating faster movement through landscapes than wider corridors. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 747 KW - activity KW - animal personality KW - wildlife corridors KW - habitat connectivity KW - individual differences KW - rodents Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-435770 SN - 1866-8372 IS - 747 ER - TY - JOUR A1 - Kowalski, Gabriele Joanna A1 - Grimm, Volker A1 - Herde, Antje A1 - Guenther, Anja A1 - Eccard, Jana T1 - Does Animal Personality Affect Movement in Habitat Corridors? BT - Experiments with Common Voles (Microtus arvalis) Using Different Corridor Widths JF - Animals N2 - Animal personality may affect an animal’s mobility in a given landscape, influencing its propensity to take risks in an unknown environment. We investigated the mobility of translocated common voles in two corridor systems 60 m in length and differing in width (1 m and 3 m). Voles were behaviorally phenotyped in repeated open field and barrier tests. Observed behavioral traits were highly repeatable and described by a continuous personality score. Subsequently, animals were tracked via an automated very high frequency (VHF) telemetry radio tracking system to monitor their movement patterns in the corridor system. Although personality did not explain movement patterns, corridor width determined the amount of time spent in the habitat corridor. Voles in the narrow corridor system entered the corridor faster and spent less time in the corridor than animals in the wide corridor. Thus, landscape features seem to affect movement patterns more strongly than personality. Meanwhile, site characteristics, such as corridor width, could prove to be highly important when designing corridors for conservation, with narrow corridors facilitating faster movement through landscapes than wider corridors. KW - activity KW - animal personality KW - wildlife corridors KW - habitat connectivity KW - individual differences KW - rodents Y1 - 2019 U6 - https://doi.org/10.3390/ani9060291 SN - 2076-2615 VL - 9 IS - 6 PB - MDPI CY - Basel ER - TY - THES A1 - Schirmer, Annika T1 - Consistent individual differences in movement-related behaviour as equalising and/or stabilising mechanisms for species coexistence T1 - Konstante individuelle Unterschiede in Bewegungs-relevanten Verhaltensweisen als stabilisierende und/oder angleichende Mechanismen für die Koexistenz von Arten N2 - 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. N2 - Ein zentrales Thema in der Ökologie ist die Koexistenz von Arten. Zwei Aspekte sind dabei von großer Bedeutung: ökologische Nischen und zwischenartliche Konkurrenz. Das Konkurrenz-Ausschlussprinzip besagt, dass der Überlappungsgrad der Nischen zweier Arten bestimmt, wie viele Ressourcen sie teilen und damit wie stark die Konkurrenz zwischen ihnen ist. Eine stabile Koexistenz zweier Arten ist nur dann möglich, wenn ihre Nischen unterschiedlich genug sind und eine geringe Überlappung vorliegt. In diesem Fall ist die innerartliche Konkurrenz größer als die zwischenartliche, und die Bedingungen für eine langfristig stabile Koexistenz sind gegeben. Traditionell werden hierbei nur mittlere Unterschiede zwischen den Fokusarten verglichen und der Einfluss von Unterschieden zwischen Individuen nicht beachtet. Ein wesentlicher Aspekt, der die Nischendifferenzierung zwischen Tierarten beeinflusst ist deren Verhalten. Dieses ist jedoch nachweislich individuell geprägt, folglich könnte der oben erwähnte Ansatz zur Koexistenz von Arten eventuell veraltet sein. Zwischen Individuen einer Art gibt es konstante Verhaltensunterschiede, die stabil bleiben über die Zeit und zwischen verschiedenen Situationen. Ursachen und Effekte dieser Unterschiede wurden bereits in zahlreichen Tierarten untersucht, wodurch ebenfalls die Integration von individuellen Verhaltensunterschieden in das Konzept der ökologischen Nische angestoßen wurde. Aspekte der Raumnutzung von Tieren fanden hierbei bislang kaum Beachtung, obwohl sie für eine Vielzahl von Parametern, die mit Nischen in Verbindung stehen, essentiell sind. Räumliches Verhalten von Tieren wird stark durch individuelle Verhaltensunterschiede beeinflusst, weswegen es eine wichtige Rolle im Zusammenhang mit individuellen Nischen spielen sollte. Hinsichtlich der Formation individueller Nischen und ökologischer Interaktionen hat die Einbeziehung von räumlichen Aspekten das Potential entscheidende Impulse zu erbringen. Die Erweiterung bestehender Theorien zu Artinteraktionen, um eine individuelle Komponente, kann neue Einblicke schaffen wie Koexistenz zwischen Arten vermittelt und örtliche Biodiversität erhalten wird. Die hier vorliegende Arbeit befasst sich mit den Einflüssen von stabilen, individuellen Verhaltensunterschieden auf die Raumnutzung von Individuen. Dies wurde exemplarisch an zwei Nagerarten untersucht, der Rötelmaus (Myodes glareolus) und der Brandmaus (Apodemus agrarius). Dabei wird der Fokus auf die folgenden Aspekte gelegt: (i) individuelle Nischen, (ii) Interaktionen zwischen Arten, und (iii) Auswirkungen verschiedener Variationsgrade stabiler Verhaltensunterschiede auf die Interaktionen innerhalb und zwischen Arten. Alle Kapitel basieren auf der gleichen Methodik in der Datenaufnahme, da individuelle Verhaltensunterschiede stets mit dem gleichen Test quantifiziert und mit räumlichen Mustern in Zusammenhang gebracht wurden, die mit Hilfe automatischer VHF Radiotelemetrie aufgezeichnet wurden. Ergebnisse sind somit auch kapitelübergreifend vergleichbar. Kapitel eins und zwei umfassen Studien an freilebenden Nagetieren aus natürlichen Populationen, während das dritte Kapitel eine experimentelle Studie unter naturnahen Bedingungen darstellt. Das erste Kapitel handelt von den Effekten stabiler Verhaltensunterschiede in der Risikobereitschaft und dem Explorationsverhalten von Rötelmäusen auf deren Bewegungsmuster. Letztere wurden nur durch die Risikobereitschaft der Individuen beeinflusst, aber nicht durch deren Explorationsverhalten. Risikofreudigere Individuen hatten größere Streifgebiete, legten längere Strecken zurück, hatten weniger innerartliche Interaktionen und bewohnten andere Mikrohabitate als risikoscheue Individuen. Gleiche Muster konnten für die Brandmäuse gefunden werden, werden jedoch erst im zweiten Kapitel dargestellt. Beide Arten besetzen somit individuelle räumliche Nischen. Kapitel zwei baut auf dem Resultat des ersten Kapitels auf und beschäftigt sich mit den Auswirkungen von individuellen räumlichen Nischen auf die Interaktionen zwischen zwei Arten. Hierbei konnte gezeigt werden, dass unabhängig von Art und Geschlecht, risikofreudigere Individuen weniger innerartliche Interaktionen haben, dafür aber mehr zwischenartliche im Vergleich zu risikoscheuen Individuen. Die Besetzung individueller Nischen hat somit zur Folge, dass das Konkurrenz-Umfeld der Individuen abhängig von ihrem Verhaltenstyp ist. Daraus folgt, dass die Interaktionen zwischen Individuen zweier Arten beschränkt sind auf solche Individuen, die sich in ihrem Verhaltenstyp, und damit ihrer Konkurrenzkraft, ähneln. Etwaige Artunterschiede in der Konkurrenzkraft könnten dadurch ausgeglichen werden und die Koexistenz der Arten vermitteln. Im letzten Kapitel wurden experimentelle Populationen aus beiden Versuchsarten zusammengestellt. Diese unterschieden sich darin, dass die Rötelmäuse entweder ausschließlich risikoscheu oder risikobereit waren, während die Brandmäuse in ihrem Verhaltenstyp variierten. Dadurch wurden Artgemeinschaften erstellt, die entweder ein vorwiegend risikoscheues oder risikobereites Konkurrenz-Umfeld hatten. Eine reduzierte Variationsbreite der individuellen Verhaltensunterschiede in einer von zwei koexistierenden Arten führt dazu, dass sich die Interaktionsmuster innerhalb und zwischen den Arten, im Vergleich zu denen aus natürlichen Populationen verändern. Brandmäuse in einem risikobereiten Konkurrenz-Umfeld hatten mehr innerartliche Interaktionen als solche in einem risikoscheuen Konkurrenz-Umfeld, unabhängig davon ob die Brandmäuse selber risikoscheu oder risikofreudig waren. Die zwischenartlichen Interaktionen dagegen wurden nur in einem risikoscheuen Konkurrenz-Umfeld von risikobereiten Brandmäusen reduziert im Gegensatz zu risikoscheuen Individuen. Währenddessen zeigen Rötelmäuse weder in den inner- noch in den zwischenartlichen Interaktionen einen Unterschied aufgrund ihres Konkurrenz-Umfeldes. Das dritte Kapitel zeigt damit deutlich, dass nicht nur stabile individuelle Unterschiede für inner- und zwischenartliche Interaktionen von Bedeutung sind, sondern dass auch die Variationsbreite der Verhaltensunterschiede innerhalb der Arten eine entscheidende Rolle spielt. Zusammenfassend verdeutlicht die vorliegende Arbeit wie wichtig die Berücksichtigung von stabilen individuellen Verhaltensunterschieden im Hinblick auf räumliche Parameter ist. Darüber hinaus zeigen die vorliegenden Ergebnisse, dass individuelle Verhaltensunterschiede für die Besetzung individueller Nischen und damit für inner- und zwischenartlichen Interaktionen von großer Bedeutung sind. Innerhalb dieser Arbeit werden individuelle Verhaltensunterschiede in Zusammenhang mit der Ähnlichkeit von Arten, der Breite von individuellen Nischen und Artnischen, sowie deren Überlappung gebracht. Diese Arbeit stellt somit eine Erweiterung des bisherigen Forschungstandes hinsichtlich der Einbeziehung von individuellen Verhaltensunterschieden in die Theorie der Koexistenz von Arten dar. KW - ecological interactions KW - inter-individual differences KW - animal personality KW - movement ecology KW - space use Y1 - 2019 ER - TY - GEN A1 - Herde, Antje A1 - Eccard, Jana T1 - Consistency in boldness, activity and exploration at different stages of life N2 - Background: Animals show consistent individual behavioural patterns over time and over situations. This phenomenon has been referred to as animal personality or behavioural syndromes. Little is known about consistency of animal personalities over entire life times. We investigated the repeatability of behaviour in common voles (Microtus arvalis) at different life stages, with different time intervals, and in different situations. Animals were tested using four behavioural tests in three experimental groups: 1. before and after maturation over three months, 2. twice as adults during one week, and 3. twice as adult animals over three months, which resembles a substantial part of their entire adult life span of several months. Results: Different behaviours were correlated within and between tests and a cluster analysis showed three possible behavioural syndrome-axes, which we name boldness, exploration and activity. Activity and exploration behaviour in all tests was highly repeatable in adult animals tested over one week. In animals tested over maturation, exploration behaviour was consistent whereas activity was not. Voles that were tested as adults with a three-month interval showed the opposite pattern with stable activity but unstable exploration behaviour. Conclusions: The consistency in behaviour over time suggests that common voles do express stable personality over short time. Over longer periods however, behaviour is more flexible and depending on life stage (i.e. tested before/after maturation or as adults) of the tested individual. Level of boldness or activity does not differ between tested groups and maintenance of variation in behavioural traits can therefore not be explained by expected future assets as reported in other studies. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 376 KW - animal personality KW - behavioural type KW - Microtus arvalis KW - common vole KW - plasticity KW - consistency KW - repeatability Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-401395 ER -