Beware of plant DNA in animal dietary metabarcoding: lessons from a strictly insectivorous bat
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ABSTRACT: DNA metabarcoding is increasingly used in dietary studies, but it faces challenges in detecting non-food taxa. Identifying plant DNA in omnivore diets is particularly difficult, as distinguishing food from non-food items is often unclear. These issues are noted in the literature, but their implications are poorly understood, limiting result interpretation and mitigation strategies.
We assessed non-food plant DNA in the diet of the insectivorous bat Tadarida teniotis, analyzing 281 faecal samples collected monthly from April to October. We modeled plant detections based on pollination syndromes, phenology, and habitat associations, and estimated co-occurrences with arthropods.
The bat’s arthropod diet was consistent with prior studies. Plant DNA was found in 82.9% of samples, representing 148 taxa. Frequent detections included species with anemophilous, entomophilous, and mixed pollination syndromes. Detection rates were higher during flowering, especially for mixed syndrome species. Fruiting had a weaker effect. Forest plants were detected more often, while riparian and agricultural plants were less common. Arthropod-plant co-occurrences were weak and inconsistent.
Our results highlight the widespread detection of non-food plant DNA in metabarcoding studies, stressing the need for caution in interpreting plant data in diets. We recommend: (i) minimizing plant contamination during sampling; (ii) using multiple negative controls; and (iii) incorporating additional information (e.g., sample inspections, literature) to better interpret results. Studies showing plant consumption patterns that diverge from traditional methods should explain steps taken to exclude non-food DNA.
ORGANISM(S): plantae Tadarida teniotis
SUBMITTER:
PROVIDER: S-BSST1641 | biostudies-other |
REPOSITORIES: biostudies-other
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