Abstract

Optimal foraging theory predicts that predators are selective when faced with abundantprey, but become less picky when prey gets sparse. Insectivorous bats in temperateregions are faced with the challenge of building up fat reserves vital forhibernation during a period of decreasing arthropod abundances. According to optimalforaging theory, prehibernating bats should adopt a less selective feeding behaviour -yet empirical studies have revealed many apparently generalized species to be composedof specialist individuals. Targeting the diet of the bat Myotis daubentonii, weused a combination of molecular techniques to test for seasonal changes in prey selectivityand individual-level variation in prey preferences. DNA metabarcoding wasused to characterize both the prey contents of bat droppings and the insect communityavailable as prey. To test for dietary differences among M. daubentonii individuals, weused ten microsatellite loci to assign droppings to individual bats. The comparisonbetween consumed and available prey revealed a preference for certain prey itemsregardless of availability. Nonbiting midges (Chironomidae) remained the most highlyconsumed prey at all times, despite a significant increase in the availability of blackflies (Simuliidae) towards the end of the season. The bats sampled showed no evidenceof individual specialization in dietary preferences. Overall, our approach offerslittle support for optimal foraging theory. Thus, it shows how novel combinations ofgenetic markers can be used to test general theory, targeting patterns at both the levelof prey communities and individual predators.

Published in

Molecular Ecology
2016, Volume: 25, number: 7, pages: 1581-1594

SLU Authors

• Roslin, Tomas

  • Department of Ecology, Swedish University of Agricultural Sciences
    
  • University of Helsinki

UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1111/mec.13564

Permanent link to this page (URI)

https://res.slu.se/id/publ/75304