@article{EccardHerdeSchusteretal.2022, author = {Eccard, Jana and Herde, Antje and Schuster, Andrea C. and Liesenjohann, Thilo and Knopp, Tatjana and Heckel, Gerald and Dammhahn, Melanie}, title = {Fitness, risk taking, and spatial behavior covary with boldness in experimental vole populations}, series = {Ecology And Evolution}, journal = {Ecology And Evolution}, publisher = {John Wiley \& Sons, Inc.}, address = {Vereinigte Staaten}, issn = {2045-7758}, doi = {10.1002/ece3.8521}, pages = {1 -- 15}, year = {2022}, abstract = {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.}, language = {en} } @article{EccardLiesenjohannDammhahn2020, author = {Eccard, Jana and Liesenjohann, Thilo and Dammhahn, Melanie}, title = {Among-individual differences in foraging modulate resource exploitation under perceived predation risk}, series = {Oecologia}, volume = {194}, journal = {Oecologia}, number = {4}, publisher = {Springer}, address = {Berlin}, issn = {0029-8549}, doi = {10.1007/s00442-020-04773-y}, pages = {621 -- 634}, year = {2020}, abstract = {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.}, language = {en} } @article{LiesenjohannLiesenjohannTrebatickaetal.2015, author = {Liesenjohann, Thilo and Liesenjohann, Monique and Trebaticka, Lenka and Sundell, Janne and Haapakoski, Marko and Ylonen, Hannu and Eccard, Jana}, title = {State-dependent foraging: lactating voles adjust their foraging behavior according to the presence of a potential nest predator and season}, series = {Behavioral ecology and sociobiology}, volume = {69}, journal = {Behavioral ecology and sociobiology}, number = {5}, publisher = {Springer}, address = {New York}, issn = {0340-5443}, doi = {10.1007/s00265-015-1889-x}, pages = {747 -- 754}, year = {2015}, abstract = {Parental care often produces a trade-off between meeting nutritional demands of offspring and the duties of offspring protection, especially in altricial species. Parents have to leave their young unattended for foraging trips, during which nestlings are exposed to predators. We investigated how rodent mothers of altricial young respond to risk of nest predation in their foraging decisions. We studied foraging behavior of lactating bank voles (Myodes glareolus) exposed to a nest predator, the common shrew (Sorex araneus). We conducted the experiment in summer (high resource provisioning for both species) and autumn (less food available) in 12 replicates with fully crossed factors "shrew presence" and "season." We monitored use of feeding stations near and far from the nest as measurement of foraging activity and strategic foraging behavior. Vole mothers adapted their strategies to shrew presence and optimized their foraging behavior according to seasonal constraints, resulting in an interaction of treatment and season. In summer, shrew presence reduced food intake from feeding stations, while it enhanced intake in autumn. Shrew presence decreased the number of visited feeding stations in autumn and concentrated mother's foraging efforts to fewer stations. Independent of shrew presence or season, mothers foraged more in patches further away from the nest than near the nest. Results indicate that females are not investing in nest guarding but try to avoid the accumulation of olfactory cues near the nest leading a predator to the young. Additionally, our study shows how foraging strategies and nest attendance are influenced by seasonal food provision.}, language = {en} } @article{EccardLiesenjohann2014, author = {Eccard, Jana and Liesenjohann, Thilo}, title = {The importance of predation risk and missed opportunity costs for context-dependent foraging patterns}, series = {PLoS one}, volume = {9}, journal = {PLoS one}, number = {5}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0094107}, pages = {5}, year = {2014}, abstract = {Correct assessment of risks and costs of foraging is vital for the fitness of foragers. Foragers should avoid predation risk and balance missed opportunities. In risk-heterogeneous landscapes animals prefer safer locations over riskier, constituting a landscape of fear. Risk-uniform landscapes do not offer this choice, all locations are equally risky. Here we investigate the effects of predation risk in patches, travelling risk between patches, and missed social opportunities on foraging decisions in risk-uniform and risk-heterogeous landscapes. We investigated patch leaving decisions of 20 common voles (M. arvalis) in three experimental landscapes: safe risk-uniform, risky risk-uniform and risk-heterogeneous. We varied both the predation risk level and the predation risk distribution between two patches experimentally and in steps, assuming that our manipulation consequently yield different distributions and levels of risk while foraging, risk while travelling, and costs of missed, social opportunities (MSOCs). We measured mean GUDs (giving-up density of food left in the patch) for both patches as a measure of foraging gain, and delta GUD, the differences among patches, as a measure of the spatial distribution of foraging effort over a period of six hours. Distribution of foraging effort was most even in the safe risk-uniform landscapes and least even in the risk-heterogeneous landscape, with risky risk-uniform landscapes in between. Foraging gain was higher in the safe than in the two riskier landscapes (both uniform and heterogeneous). Results supported predictions for the effects of risk in foraging patches and while travelling between patches, however predictions for the effects of missed social opportunities were not met in this short term experiment. Thus, both travelling and foraging risk contribute to distinct patterns observable high risk, risk-uniform landscapes.}, language = {en} } @article{LiesenjohannLiesenjohannPalmeetal.2013, author = {Liesenjohann, Monique and Liesenjohann, Thilo and Palme, Rupert and Eccard, Jana}, title = {Differential behavioural and endocrine responses of common voles (Microtus arvalis) to nest predators and resource competitors}, series = {BMC ecology}, volume = {13}, journal = {BMC ecology}, number = {17}, publisher = {BioMed Central}, address = {London}, issn = {1472-6785}, doi = {10.1186/1472-6785-13-33}, pages = {10}, year = {2013}, abstract = {Background: Adaptive behavioural strategies promoting co-occurrence of competing species are known to result from a sympatric evolutionary past. Strategies should be different for indirect resource competition (exploitation, e.g., foraging and avoidance behaviour) than for direct interspecific interference (e.g., aggression, vigilance, and nest guarding). We studied the effects of resource competition and nest predation in sympatric small mammal species using semi-fossorial voles and shrews, which prey on vole offspring during their sensitive nestling phase. Experiments were conducted in caged outdoor enclosures. Focus common vole mothers (Microtus arvalis) were either caged with a greater white-toothed shrew (Crocidura russula) as a potential nest predator, with an herbivorous field vole (Microtus agrestis) as a heterospecific resource competitor, or with a conspecific resource competitor. Results: We studied behavioural adaptations of vole mothers during pregnancy, parturition, and early lactation, specifically modifications of the burrow architecture and activity at burrow entrances. Further, we measured pre- and postpartum faecal corticosterone metabolites (FCMs) of mothers to test for elevated stress hormone levels. Only in the presence of the nest predator were prepartum FCMs elevated, but we found no loss of vole nestlings and no differences in nestling body weight in the presence of the nest predator or the heterospecific resource competitor. Although the presence of both the shrew and the field vole induced prepartum modifications to the burrow architecture, only nest predators caused an increase in vigilance time at burrow entrances during the sensitive nestling phase. Conclusion: Voles displayed an adequate behavioural response for both resource competitors and nest predators. They modified burrow architecture to improve nest guarding and increased their vigilance at burrow entrances to enhance offspring survival chances. Our study revealed differential behavioural adaptations to resource competitors and nest predators.}, language = {en} } @article{KrauseLiesenjohann2012, author = {Krause, E. Tobias and Liesenjohann, Thilo}, title = {Predation pressure and food abundance during early life alter risk-taking behaviour and growth of guppies (Poecilia reticulata)}, series = {Behaviour : an international journal of behavioural biology}, volume = {149}, journal = {Behaviour : an international journal of behavioural biology}, number = {1}, publisher = {Brill}, address = {Leiden}, issn = {0005-7959}, doi = {10.1163/156853912X623748}, pages = {1 -- 14}, year = {2012}, abstract = {The trade-off between predation risk and the need to feed is one of the major constraints animals have to cope with. Virtually all animals have a higher risk of being preyed upon when being active (e.g., searching for food or mating partners), compared with being inactive (e.g., staying at their burrows, nests, etc.). Yet, staying safe leads to a higher risk of starvation and may reduce reproductive success and body growth. Hence selection on behaviour optimizing the search, handling and digestion of food while avoiding the risk of predation is strong and should lead to strategies maximising survival chances and inclusive fitness. These facts call for integrative studies manipulating both, abundance of food and predation risk in a factorial set up, analysing the effects of both factors on behaviour and physiological parameters. We present results of a 2 x 2 factorial experiment, manipulating risk of predation and food abundance in guppies. We found that the two factors have an additive effect on body growth, but that predation risk by a pike cichlid is the main factor affecting the expression of behavioural strategies in guppies. Low food availability and high predation risk led to lower body growth. High predation risk affected swimming depth and risk sensitivity of guppies and might represent adaptive behavioural changes to the environmental context experienced in early life. Our study shows that integrative studies, analysing multiple interdependent and interconnected factors in the wild and in the lab are needed to further understand animal behaviour and development.}, language = {en} } @article{LiesenjohannLiesenjohannTrebatickaetal.2011, author = {Liesenjohann, Monique and Liesenjohann, Thilo and Trebaticka, Lenka and Haapakoski, Marko and Sundell, Janne and Ylonen, Hannu and Eccard, Jana}, title = {From interference to predation type and effects of direct interspecific interactions of small mammals}, series = {Behavioral ecology and sociobiology}, volume = {65}, journal = {Behavioral ecology and sociobiology}, number = {11}, publisher = {Springer}, address = {New York}, issn = {0340-5443}, doi = {10.1007/s00265-011-1217-z}, pages = {2079 -- 2089}, year = {2011}, abstract = {Indirect exploitative competition, direct interference and predation are important interactions affecting species coexistence. These interaction types may overlap and vary with the season and life-history state of individuals. We studied effects of competition and potential nest predation by common shrews (Sorex araneus) on lactating bank voles (Myodes glareolus) in two seasons. The species coexist and may interact aggressively. Additionally, shrews can prey on nestling voles. We studied bank vole mothers' spatial and temporal adaptations to shrew presence during summer and autumn. Further, we focused on fitness costs, e.g. decreased offspring survival, which bank voles may experience in the presence of shrews. In summer, interference with shrews decreased the voles' home ranges and they spent more time outside the nest, but there were no effects on offspring survival. In autumn, we found decreased offspring survival in enclosures with shrews, potentially due to nest predation by shrews or by increased competition between species. Our results indicate a shift between interaction types depending on seasonal constraints. In summer, voles and shrews seem to interact mainly by interference, whereas resource competition and/or nest predation by shrews gain importance in autumn. Different food availability, changing environmental conditions and the energetic constraints in voles and shrews later in the year may be the reasons for the varying combinations of interaction types and their increasing effects on the inclusive fitness of bank voles. Our study provides evidence for the need of studies combining life history with behavioural measurements and seasonal constraints.}, language = {en} }