Combining Time-Stamped Insect Sampling With eDNA-Metabarcoding of Guano to Reconstruct Community Interactions

Area of Science:

• Ecology
• Molecular Biology
• Conservation Biology

Background:

• Predator-prey dynamics are crucial for predicting responses to environmental change.
• Bats, as apex predators, offer insights into ecosystem health by reflecting insect community changes.
• Existing molecular diet studies lack temporal resolution, hindering understanding of bat hunting strategies and prey selection.

Purpose of the Study:

• To investigate the foraging ecology of long-eared bats (Plecotus sp.) by integrating temporal data.
• To overcome limitations of previous studies by combining environmental DNA (eDNA) metabarcoding of bat guano with time-stamped insect metabarcoding.
• To infer prey selection mechanisms and hunting strategies based on temporal foraging patterns.

Main Methods:

• Collected bat guano and time-stamped insect samples using automated Malaise traps.
• Utilized eDNA metabarcoding for both bat guano and insect samples.
• Analyzed and compared prey communities from guano with temporal insect activity data.

Main Results:

• Bat guano prey composition closely matched insect samples collected between 22:00 and 6:00.
• Identified species-specific peak foraging times and prey composition.
• Detected distinct prey selection patterns between Plecotus auritus and Plecotus austriacus, reflecting different hunting strategies.

Conclusions:

• Integrating a temporal dimension into molecular diet analysis allows direct inference of prey selection and foraging behavior from bat guano.
• This approach enhances biodiversity monitoring and provides tools for conservation planning in changing environments.
• The study highlights the importance of temporal data for understanding predator-prey interactions and informing conservation strategies.