Separating effects of competition, interference and predation in an experimental study system with small mammals
Zusammenfassung der Projektergebnisse
In the DFG funded project separating effects of competition, interference and predation in an experimental study system with small mammals we questioned the rigid use of ecological categories of interspecific interactions. We used an individual-based approach to understand effects of antagonist interspecific interactions, which may not be spread equally over the population but may affect only certain functional categories of the population in defined life-history time windows. We conducted behavioural experiments, dyadic encounters, and created experimental communities in well replicated experimental designs using different 2-species systems of small mammals: voles and shrews, and two vole species. Our results indicate that voles actively protect their nests against shrew predation, by spending more time near the nest and changing their foraging behaviour in the presence of shrews compared to absence. Further, the threat of nest predation is seasonally variable and probably depends on the availability of alternative prey. Voles adjust their response to shrew presence in accordance e to the season. Thus, nest predation by shrews seems to a common event evoking behavioural adaptations of voles, which came as surprise to many small mammal ecologists. In two-species vole systems we found that antagonists may shift their behaviour from resource competition and mutual avoidance in winter to aggressive interaction and interference competition during summer. Future research in the field may include ecological modelling of interspecific interactions based on our results and a continuation of automated radio-tracking of individuals of two species to understand spatial interaction patterns. Our project indicates, that agonistic ecological interaction types can dynamically transform from one type into another, depending on environment and life history stage of the involved individuals. Ecological theory therefore needs dynamic concepts to capture the interspecific interactions in animal communities.
Projektbezogene Publikationen (Auswahl)
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2007, DZG (Annual Meeting, Cologne): Competition and Interference between small mammal guilds - behavioural adaptations
Eccard, Ellmer et al.
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2008 DZG (Annual Meeting, Jena): Foraging under pressure - effects of season and interspecific interference on lactating bank voles
Liesenjohann, Eccard & Ellmer
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2008 European Conference on Behavioural Biology (Bi-annual Meeting, Dijon): Interference and predation in a vole-shrew study system: effects and seasonal variation
Ellmer , Liesenjohann & Eccard
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2008, DZG (Annual Meeting, Jena): Encounters underground – Effects of shrew presence on the burrowing behaviour of common voles
Barber, Ellmer & Eccard
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2009 Landschaftsmosaik und Risikouniformität – Auswirkungen zwischenartlicher Interaktionen auf Verhalten und Lebensgeschichte von Kleinäugern in der Kulturlandschaft. Mitteilungen Julius Kühn-Institut 421: 30-36
Eccard, JA
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(2010) Does spatial learning ability of common voles (Microtus arvalis) and bank voles (Myodes glareolus) constrain foraging efficiency? Animal Cognition 13: 783-91
Haupt, M, Eccard, JA, Winter, Y
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(2011) Breeding state and season affect interspecific interaction types: indirect resource competition and direct interference. Oecologia 1-11
Eccard JA, Fey K, Caspers BA, Ylönen H
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(2011). From interference to predation: type and effects of direct interspecific interactions of small mammals. Behavioural Ecology and Sociobiology 65:2079-2089
Liesenjohann M, Liesenjohann T, Trebaticka L, Haapakoski M, Sundell J, Ylönen H, Eccard JA
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2011 DZG, German Zoological Society (Annual Meeting, Saarbrücken): The Ghost of Nest Predation Past – adaptive behavioural strategies of vole mothers
Liesenjohann & Eccard
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(2013) Differential behavioural and endocrine responses of common voles (Microtus arvalis) to nest predators and resource competitors. BMC Ecology 13:33
Liesenjohann M, Liesenjohann T, Palme R, Eccard JA
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(2013) Interspecific interaction types and their effect on behaviour and fitness. Universität Potsdam, Hochschulschriften der Mathematisch-Naturwissenschaftlichen Fakultät, Dissertation
Liesenjohann, M.
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(2013) Reducing mortality of shrews in rodent live trapping - a method increasing live-trap selectivity with shrew exits. Annales Zoologici Fennici, 50, 371-376
Eccard JA, Klemme I
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2014 ICRBM (Intl. Conference on Rodent Biology and Management Zhenzhou, China): Behavioural ecology of rodents and individual differences in seasonal environments
Eccard, Jana
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(2015) State-dependent foraging: lactating voles adjust their foraging behavior according to the presence of a potential nest predator and season. Behavioural Ecology and Sociobiology 69(5): 747–754
Liesenjohann T, Liesenjohann M, Trebaticka L, Sundell J, Haapakoski M, Ylönen H, Eccard JA
