Data from: Testing the validity of functional response models using molecular gut content analysis for prey choice in soil predators
Eitzinger, Bernhard, University of Göttingen, University of Helsinki
Rall, Björn, Friedrich Schiller University Jena, German Center for Integrative Biodiversity Research
Traugott, Michael, University of Innsbruck
Scheu, Stefan, University of Göttingen
Published Dec 11, 2017 on Dryad.
Cite this dataset
Eitzinger, Bernhard; Rall, Björn; Traugott, Michael; Scheu, Stefan (2017). Data from: Testing the validity of functional response models using molecular gut content analysis for prey choice in soil predators [Dataset]. Dryad. https://doi.org/10.5061/dryad.31t0k
Analysis of predator - prey interactions is a core concept of animal ecology, explaining structure and dynamics of animal food webs. Measuring the functional response, i.e. the intake rate of a consumer as a function of prey density, is a powerful method to predict the strength of trophic links and assess motives of prey choice, particularly in arthropod communities. However, due to their reductionist set-up, functional responses, which are based on laboratory feeding experiments, may not display field conditions, possibly leading to skewed results. Here, we tested the validity of functional responses of centipede predators and their prey by comparing them with empirical gut content data from field-collected predators. Our predator - prey system included lithobiid and geophilomorph centipedes, abundant and widespread predators of forest soils and their soil-dwelling prey. First, we calculated the body size-dependent functional responses of centipedes using a published functional response model in which we included natural prey abundances and animal body masses. This allowed us to calculate relative proportions of specific prey taxa in the centipede diet. In a second step, we screened field-collected centipedes for DNA of eight abundant soil-living prey taxa and estimated their body size-dependent proportion of feeding events. We subsequently compared empirical data for each of the eight prey taxa, on proportional feeding events with functional response-derived data on prey proportions expected in the gut, showing that both approaches significantly correlate in five out of eight predator - prey links for lithobiid centipedes but only in one case for geophilomorph centipedes. Our findings suggest that purely allometric functional response models, which are based on predator-prey body size ratios are too simple to explain predator - prey interactions in a complex system such as soil. We therefore stress that specific prey traits, such as defence mechanisms, must be considered for accurate predictions.
Eitzinger et al_Testing validity Funct Respon_Raw data
Matrix of centipede predator individuals (collected from four forest sites in Thuringia, Germany on eight dates during 2009 and 2010) which were tested for consumption of 14 soil prey groups by molecular gut content analysis. Matrix contains taxonomic details of centipede predators as well as their sex, body size (mm), body mass (mg) and development stage. Consumption of prey (=positive detection of prey DNA) is denoted as '1', non-consumption as '0'. If predators were not tested cells contain 'NA'.