WHAT SHAPES BAT’S DIETS? TROPHIC SNAPSHOT OF A MEDITERRANEAN BAT COMMUNITY

WHAT SHAPES BAT’S DIETS? TROPHIC SNAPSHOT OF A MEDITERRANEAN BAT COMMUNITY

Vanessa Mata (CIBIO-InBIO, Portugal) | June 17, 2019 | 8th International Barcode of Life Conference, Trondheim, Norway

Background: Predator–prey interactions forge the behavior and ecology of all organisms and are therefore crucial in structuring ecological communities. In bats, these are believed to be constrained by the interaction of species morphology, echolocation, and foraging behavior. Several studies have emphasized the role of these traits in prey acquisition and have tried to group bats accordingly in guilds. However, due to practical difficulties in studying entire communities and the constraints of morphology-based diet analysis, it is not clear how these guilds actually correlate to the diet of insectivorous bats. To better understand this question, we used DNA metabarcoding to assess the diet of a Mediterranean bat community located in northeast Portugal composed of 19 different species. Results: Bat droppings were collected from 486 individual bats, and DNA was extracted from 1206 individual pellets (up to three per bat). We amplified prey DNA using two nonoverlapping COI markers, ZBJ and Fwh2, to detect the maximum number of prey at the highest taxonomic resolution possible. We used a canonical and ecological network analysis to assess the dietary guilds. Bats were structured in 4–5 diet groups, three of which were very distinct and fed on either noctuid moths, crickets, or spiders, respectively. The fourth and fifth groups were mainly characterized by not feeding on these taxa and ingesting more Coleoptera, Diptera, and Hemiptera. None of the diet groups corresponded to previously suggested echolocation or foraging guilds, with the exception of Myotis myotis, the only ground-gleaning bat in our community, which formed a guild on its own. Significance: For the first time, we provide empirical evidence for the existence of dietary guilds in Mediterranean insectivorous bat communities and show that these do not correlate to previously proposed guilds based on echolocation signal and foraging habitat, mode, site, or vegetation clutter.