TY - JOUR A1 - Schlägel, Ulrike E. A1 - Mädlow, Wolfgang T1 - All-season space use by non-native resident Mandarin Ducks (Aix galericulata) in northeastern Germany JF - Journal of ornithology / publ. by Deutsche Ornithologen-Gesellschaft N2 - Patterns of space use are often subject to large temporal and individual-level variation, due to seasonality in behaviour and environmental conditions as well as age- or sex-specific needs. Especially in temperate regions, seasonality likely influences space use even in non-migratory birds. In waterfowl of the family Anatidae, however, few studies have analyzed space use of the same individuals across the full annual cycle. We used a resident population of Mandarin Ducks (Aix galericulata) in northeast Germany to study their year-round space use in relation to season, sex, and age. We marked 172 birds with colour rings and surveyed relevant water bodies for re-encounters for several years. As space-use patterns we derived home ranges from minimum convex polygons and the number of water bodies used by individual birds. Our analysis revealed that individuals shifted their space use between seasons, in particular extending their home ranges during the non-breeding season. Between years, in contrast, birds tended to show season-specific site fidelity. Sex differences were apparent during both breeding and non-breeding season, males consistently having larger home ranges and using slightly more water bodies. No difference was found between first-year and adult birds. Our study demonstrates that mark-resighting can provide valuable information about space use in species with suitable behaviour and readily accessible habitat. In such cases, it may be a valid alternative to more expensive GPS-tracking or short-term manual radio telemetry, particularly within citizen-science projects. N2 - Raumnutzungsmuster von Vögeln zeigen häufig große zeitliche und individuelle Variationen in Abhängigkeit vom saisonalen Verhalten und von Umweltbedingungen, aber auch alters- und geschlechtsspezifischen Ansprüchen. In gemäßigten Klimazonen können jahreszeitliche Einflussfaktoren die Raumnutzung auch von nicht ziehenden Arten bestimmen. Für Entenvögel (Anatidae) liegen bisher jedoch nur wenige Studien vor, die die Raumnutzung von Individuen über den gesamten Jahresverlauf hinweg betrachten. Wir untersuchten die ganzjährige Raumnutzung einer Standvogel-Population der Mandarinente (Aix galericulata) in Abhängigkeit von Jahreszeit, Geschlecht und Alter der Vögel. Wir markierten 172 Vögel mit Farbringen und kontrollierten mehrere Jahre lang die relevanten Gewässer, um Ringablesungen zu erzielen. Zur Analyse der Raumnutzung ermittelten wir Minimum-Convex-Polygone und die Anzahl der von den einzelnen Individuen genutzten Gewässer. Unsere Auswertung zeigte, dass die von den Vögeln genutzten Aktionsräume sich mit den Jahreszeiten veränderten. Insbesondere vergrößerte sich das besuchte Gebiet außerhalb der Brutzeit. Beim Vergleich mehrerer Jahre tendierten die Vögel zu einer saisonspezifischen Gebietstreue. Geschlechterunterschiede zeigten sich sowohl innerhalb als auch außerhalb der Brutzeit, wobei die Männchen stets größere Gebiete und eine größere Zahl an Gewässern nutzten. Zwischen Vögeln im ersten Lebensjahr und Adulten wurden keine Unterschiede gefunden. Unsere Untersuchung zeigt, dass Farbberingungsprogramme wertvolle Informationen zur Raumnutzung bei Arten liefern können, deren Verhalten dafür geeignet ist und die in gut zugänglichen Lebensräumen vorkommen. In diesen Fällen kann die Farbberingung eine geeignete Alternative zur teureren GPS- oder manuellen Telemetrie sein, vor allem wenn die vereinte Kraft von Amateurornithologen in die Untersuchungen einbezogen werden kann. KW - Anatidae KW - Aix galericulata KW - Home range KW - Site fidelity KW - Movement KW - Seasonality Y1 - 2021 U6 - https://doi.org/10.1007/s10336-021-01932-7 SN - 2193-7192 SN - 2193-7206 VL - 163 IS - 1 SP - 71 EP - 82 PB - Springer CY - Berlin ER - TY - GEN A1 - Parry, Victor A1 - Schlägel, Ulrike E. A1 - Tiedemann, Ralph A1 - Weithoff, Guntram T1 - Behavioural Responses of Defended and Undefended Prey to Their Predator BT - A Case Study of Rotifera T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Predation is a strong species interaction causing severe harm or death to prey. Thus, prey species have evolved various defence strategies to minimize predation risk, which may be immediate (e.g., a change in behaviour) or transgenerational (morphological defence structures). We studied the behaviour of two strains of a rotiferan prey (Brachionus calyciflorus) that differ in their ability to develop morphological defences in response to their predator Asplanchna brightwellii. Using video analysis, we tested: (a) if two strains differ in their response to predator presence and predator cues when both are undefended; (b) whether defended individuals respond to live predators or their cues; and (c) if the morphological defence (large spines) per se has an effect on the swimming behaviour. We found a clear increase in swimming speed for both undefended strains in predator presence. However, the defended specimens responded neither to the predator presence nor to their cues, showing that they behave indifferently to their predator when they are defended. We did not detect an effect of the spines on the swimming behaviour. Our study demonstrates a complex plastic behaviour of the prey, not only in the presence of their predator, but also with respect to their defence status. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1302 KW - animal behaviour KW - transgenerational response KW - Brachionus calyciflorus KW - Asplanchna brightwellii KW - video analysis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-577594 SN - 1866-8372 IS - 1302 ER - TY - JOUR A1 - Parry, Victor A1 - Schlägel, Ulrike E. A1 - Tiedemann, Ralph A1 - Weithoff, Guntram T1 - Behavioural Responses of Defended and Undefended Prey to Their Predator BT - A Case Study of Rotifera JF - Biology N2 - Predation is a strong species interaction causing severe harm or death to prey. Thus, prey species have evolved various defence strategies to minimize predation risk, which may be immediate (e.g., a change in behaviour) or transgenerational (morphological defence structures). We studied the behaviour of two strains of a rotiferan prey (Brachionus calyciflorus) that differ in their ability to develop morphological defences in response to their predator Asplanchna brightwellii. Using video analysis, we tested: (a) if two strains differ in their response to predator presence and predator cues when both are undefended; (b) whether defended individuals respond to live predators or their cues; and (c) if the morphological defence (large spines) per se has an effect on the swimming behaviour. We found a clear increase in swimming speed for both undefended strains in predator presence. However, the defended specimens responded neither to the predator presence nor to their cues, showing that they behave indifferently to their predator when they are defended. We did not detect an effect of the spines on the swimming behaviour. Our study demonstrates a complex plastic behaviour of the prey, not only in the presence of their predator, but also with respect to their defence status. KW - animal behaviour KW - transgenerational response KW - Brachionus calyciflorus KW - Asplanchna brightwellii KW - video analysis Y1 - 2022 U6 - https://doi.org/10.3390/biology11081217 SN - 2079-7737 VL - 11 IS - 8 PB - MDPI CY - Basel, Schweiz ER - TY - JOUR A1 - Parry, Victor A1 - Schlägel, Ulrike E. A1 - Tiedemann, Ralph A1 - Weithoff, Guntram T1 - Behavioural responses of defended and undefended prey to their predator BT - a case study of rotifera JF - Biology : open access journal N2 - Many animals that have to cope with predation have evolved mechanisms to reduce their predation risk. One of these mechanisms is change in morphology, for example, the development of spines. These spines are induced, when mothers receive chemical signals of a predator (kairomones) and their daughters are then equipped with defensive spines. We studied the behaviour of a prey and its predator when the prey is either defended or undefended. We used common aquatic micro-invertebrates, the rotifers Brachionus calyciflorus (prey) and Asplanchna brightwellii (predator) as experimental animals. We found that undefended prey increased its swimming speed in the presence of the predator. The striking result was that the defended prey did not respond to the predator's presence. This suggests that defended prey has a different response behaviour to a predator than undefended conspecifics. Our study provides further insights into complex zooplankton predator-prey interactions. Predation is a strong species interaction causing severe harm or death to prey. Thus, prey species have evolved various defence strategies to minimize predation risk, which may be immediate (e.g., a change in behaviour) or transgenerational (morphological defence structures). We studied the behaviour of two strains of a rotiferan prey (Brachionus calyciflorus) that differ in their ability to develop morphological defences in response to their predator Asplanchna brightwellii. Using video analysis, we tested: (a) if two strains differ in their response to predator presence and predator cues when both are undefended; (b) whether defended individuals respond to live predators or their cues; and (c) if the morphological defence (large spines) per se has an effect on the swimming behaviour. We found a clear increase in swimming speed for both undefended strains in predator presence. However, the defended specimens responded neither to the predator presence nor to their cues, showing that they behave indifferently to their predator when they are defended. We did not detect an effect of the spines on the swimming behaviour. Our study demonstrates a complex plastic behaviour of the prey, not only in the presence of their predator, but also with respect to their defence status. KW - animal behaviour KW - transgenerational response KW - Brachionus calyciflorus KW - Asplanchna brightwellii KW - video analysis Y1 - 2022 U6 - https://doi.org/10.3390/biology11081217 SN - 2079-7737 VL - 11 IS - 8 PB - MDPI CY - Basel ER - TY - JOUR A1 - Potts, Jonathan R. A1 - Schlägel, Ulrike E. T1 - Parametrizing diffusion-taxis equations from animal movement trajectories using step selection analysis JF - Methods in ecology and evolution : an official journal of the British Ecological Society N2 - 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. KW - advection-diffusion KW - animal movement KW - home range KW - movement ecology KW - partial differential equations KW - resource selection KW - step selection KW - taxis Y1 - 2020 U6 - https://doi.org/10.1111/2041-210X.13406 SN - 2041-210X VL - 11 IS - 9 SP - 1092 EP - 1105 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Colangeli, Pierluigi A1 - Schlägel, Ulrike E. A1 - Obertegger, Ulrike A1 - Petermann, Jana S. A1 - Tiedemann, Ralph A1 - Weithoff, Guntram T1 - Negative phototactic response to UVR in three cosmopolitan rotifers: a video analysis approach JF - Hydrobiologia : acta hydrobiologica, hydrographica, limnologica et protistologica KW - Risk avoidance behavior KW - Brachionus calyciflorus KW - Keratella cochlearis KW - BEMOVI KW - Movement ecology Y1 - 2018 U6 - https://doi.org/10.1007/s10750-018-3801-y SN - 0018-8158 SN - 1573-5117 VL - 844 IS - 1 SP - 43 EP - 54 PB - Springer CY - Dordrecht ER - TY - GEN A1 - Jeltsch, Florian A1 - Grimm, Volker A1 - Reeg, Jette A1 - Schlägel, Ulrike E. T1 - Give chance a chance BT - from coexistence to coviability in biodiversity theory T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - A large part of biodiversity theory is driven by the basic question of what allows species to coexist in spite of a confined number of niches. A substantial theoretical background to this question is provided by modern coexistence theory (MCT), which rests on mathematical approaches of invasion analysis to categorize underlying mechanisms into factors that reduce either niche overlap (stabilizing mechanisms) or the average fitness differences of species (equalizing mechanisms). While MCT has inspired biodiversity theory in the search for these underlying mechanisms, we feel that the strong focus on coexistence causes a bias toward the most abundant species and neglects the plethora of species that are less abundant and often show high local turnover. Given the more stochastic nature of their occurrence, we advocate a complementary cross-level approach that links individuals, small populations, and communities and explicitly takes into account (1) a more complete inclusion of environmental and demographic stochasticity affecting small populations, (2) intraspecific trait variation and behavioral plasticity, and (3) local heterogeneities, interactions, and feedbacks. Focusing on mechanisms that drive the temporary coviability of species rather than infinite coexistence, we suggest a new approach that could be dubbed coviability analysis (CVA). From a modeling perspective, CVA builds on the merged approaches of individual-based modeling and population viability analysis but extends them to the community level. From an empirical viewpoint, CVA calls for a stronger integration of spatiotemporal data on variability and noise, changing drivers, and interactions at the level of individuals. The resulting large volumes of data from multiple sources could be strongly supported by novel techniques tailored to the discovery of complex patterns in high-dimensional data. By complementing MCT through a stronger focus on the coviability of less common species, this approach can help make modern biodiversity theory more comprehensive, predictive, and relevant for applications. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 742 KW - behavioral plasticity KW - biodiversity KW - coexistence KW - community theory KW - coviability analysis KW - demographic noise KW - environmental noise KW - heterogeneity KW - individual-based modeling KW - intraspecific trait variation KW - modern coexistence theory KW - population viability analysis Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-435320 SN - 1866-8372 IS - 742 ER - TY - JOUR A1 - Jeltsch, Florian A1 - Grimm, Volker A1 - Reeg, Jette A1 - Schlägel, Ulrike E. T1 - Give chance a chance BT - from coexistence to coviability in biodiversity theory JF - Ecosphere N2 - A large part of biodiversity theory is driven by the basic question of what allows species to coexist in spite of a confined number of niches. A substantial theoretical background to this question is provided by modern coexistence theory (MCT), which rests on mathematical approaches of invasion analysis to categorize underlying mechanisms into factors that reduce either niche overlap (stabilizing mechanisms) or the average fitness differences of species (equalizing mechanisms). While MCT has inspired biodiversity theory in the search for these underlying mechanisms, we feel that the strong focus on coexistence causes a bias toward the most abundant species and neglects the plethora of species that are less abundant and often show high local turnover. Given the more stochastic nature of their occurrence, we advocate a complementary cross-level approach that links individuals, small populations, and communities and explicitly takes into account (1) a more complete inclusion of environmental and demographic stochasticity affecting small populations, (2) intraspecific trait variation and behavioral plasticity, and (3) local heterogeneities, interactions, and feedbacks. Focusing on mechanisms that drive the temporary coviability of species rather than infinite coexistence, we suggest a new approach that could be dubbed coviability analysis (CVA). From a modeling perspective, CVA builds on the merged approaches of individual-based modeling and population viability analysis but extends them to the community level. From an empirical viewpoint, CVA calls for a stronger integration of spatiotemporal data on variability and noise, changing drivers, and interactions at the level of individuals. The resulting large volumes of data from multiple sources could be strongly supported by novel techniques tailored to the discovery of complex patterns in high-dimensional data. By complementing MCT through a stronger focus on the coviability of less common species, this approach can help make modern biodiversity theory more comprehensive, predictive, and relevant for applications. KW - behavioral plasticity KW - biodiversity KW - coexistence KW - community theory KW - coviability analysis KW - demographic noise KW - environmental noise KW - heterogeneity KW - individual-based modeling KW - intraspecific trait variation KW - modern coexistence theory KW - population viability analysis Y1 - 2019 U6 - https://doi.org/10.1002/ecs2.2700 SN - 2150-8925 VL - 10 IS - 5 PB - ESA CY - Ithaca, NY ER - TY - JOUR A1 - Schlägel, Ulrike E. A1 - Signer, Johannes A1 - Herde, Antje A1 - Eden, Sophie A1 - Jeltsch, Florian A1 - Eccard, Jana A1 - Dammhahn, Melanie T1 - Estimating interactions between individuals from concurrent animal movements JF - Methods in ecology and evolution : an official journal of the British Ecological Society N2 - Animal movements arise from complex interactions of individuals with their environment, including both conspecific and heterospecific individuals. Animals may be attracted to each other for mating, social foraging, or information gain, or may keep at a distance from others to avoid aggressive encounters related to, e.g., interference competition, territoriality, or predation. With modern tracking technology, more datasets are emerging that allow to investigate fine‐scale interactions between free‐ranging individuals from movement data, however, few methods exist to disentangle fine‐scale behavioural responses of interacting individuals when these are highly individual‐specific. In a framework of step‐selection functions, we related movements decisions of individuals to dynamic occurrence distributions of other individuals obtained through kriging of their movement paths. Using simulated data, we tested the method's ability to identify various combinations of attraction, avoidance, and neutrality between individuals, including asymmetric (i.e. non‐mutual) behaviours. Additionally, we analysed radio‐telemetry data from concurrently tracked small rodents (bank vole, Myodes glareolus) to test whether our method could detect biologically plausible behaviours. We found that our method was able to successfully detect and distinguish between fine‐scale interactions (attraction, avoidance, neutrality), even when these were asymmetric between individuals. The method worked best when confounding factors were taken into account in the step‐selection function. However, even when failing to do so (e.g. due to missing information), interactions could be reasonably identified. In bank voles, responses depended strongly on the sexes of the involved individuals and matched expectations. Our approach can be combined with conventional uses of step‐selection functions to tease apart the various drivers of movement, e.g. the influence of the physical and the social environment. In addition, the method is particularly useful in studying interactions when responses are highly individual‐specific, i.e. vary between and towards different individuals, making our method suitable for both single‐species and multi‐species analyses (e.g. in the context of predation or competition). KW - attraction-avoidance KW - fine-scale interactions KW - individual variability KW - inter-specific interactions KW - movement behaviour KW - occurrence estimates KW - social environment KW - step-selection function Y1 - 2019 U6 - https://doi.org/10.1111/2041-210X.13235 SN - 2041-210X SN - 2041-2096 VL - 10 IS - 8 SP - 1234 EP - 1245 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Crawford, Michael A1 - Jeltsch, Florian A1 - May, Felix A1 - Grimm, Volker A1 - Schlägel, Ulrike E. T1 - Intraspecific trait variation increases species diversity in a trait-based grassland model JF - Oikos N2 - Intraspecific trait variation (ITV) is thought to play a significant role in community assembly, but the magnitude and direction of its influence are not well understood. Although it may be critical to better explain population persistence, species interactions, and therefore biodiversity patterns, manipulating ITV in experiments is challenging. We therefore incorporated ITV into a trait‐ and individual‐based model of grassland community assembly by adding variation to the plants’ functional traits, which then drive life‐history tradeoffs. Varying the amount of ITV in the simulation, we examine its influence on pairwise‐coexistence and then on the species diversity in communities of different initial sizes. We find that ITV increases the ability of the weakest species to invade most, but that this effect does not scale to the community level, where the primary effect of ITV is to increase the persistence and abundance of the competitively‐average species. Diversity of the initial community is also of critical importance in determining ITV's efficacy; above a threshold of interspecific diversity, ITV does not increase diversity further. For communities below this threshold, ITV mainly helps to increase diversity in those communities that would otherwise be low‐diversity. These findings suggest that ITV actively maintains diversity by helping the species on the margins of persistence, but mostly in habitats of relatively low alpha and beta diversity. KW - community assembly KW - individual-based model KW - intraspecific trait variation Y1 - 2018 U6 - https://doi.org/10.1111/oik.05567 SN - 0030-1299 SN - 1600-0706 VL - 128 IS - 3 SP - 441 EP - 455 PB - Wiley CY - Hoboken ER -