By way of the evaluation of DNA traces within the droppings of a Leisler’s bat colony, researchers at LIB have now recognized over 350 completely different insect species that have been consumed by the bats.

Sufficient meals provide is a basic want and requirement for survival. To guard a species, it’s usually very useful to know what that species prefers and steadily consumes. By way of the evaluation of DNA traces within the droppings of a Leisler’s bat colony, researchers at LIB (Leibniz Institute for the Evaluation of Biodiversity Change) have now recognized an astonishingly excessive quantity —over 350— completely different insect species that have been consumed by the bats.

Particularly for small animal species and people which can be nocturnal, it may be extraordinarily troublesome to find out what they feed on. Figuring out small prey bugs or their stays can be hardly ever potential right down to the precise species or household. Within the case of the studied bat species, there may be the extra problem that it’s a forest bat species that must be positioned first. “Following bats equipped with radio transmitters in the forest at night is quite special,” says Martin Koch, co-initiator of the research.

Luckily — but in addition complicating issues — there are about 13 completely different bat species residing within the investigated space close to Bonn, within the forests of the Natura 2000 space ‘Waldreservat Kottenforst.’ Initially, as a part of an EU Life+ undertaking, roosts — the bushes the place the bats stay — of the Leisler’s bats have been recognized, from which the research’s beginning materials was then obtained. This was performed utilizing a specifically developed “guano trap.” The entice consists of roughly 2.2 sq. meters of mosquito netting stretched rectangularly.

It was put in about 3 meters excessive on the tree trunk, under the doorway to the roosting cavity at about 9 meters excessive. Throughout the so-called “twilight swarming” after the nightly insect hunt, the bats return to the roosting cavity and initially circle the tree. They steadily perch briefly subsequent to the cavity entrance and stick a small guano pellet to the trunk. Recurrently, pellets fall and land within the mosquito netting below the cavity entrance. This “bat guano” was collected, mounted, and additional processed within the laboratory.

“It’s fascinating how much DNA you can extract from a small amount of droppings and how much information we can draw from the DNA: from which bat species does the droppings come, and what has the bat eaten?” explains Dr. Kathrin Langen. Utilizing the DNA contained within the droppings, our researchers have been capable of decide 9 samples from 9 completely different nights when solely the goal species swarmed across the roosting tree. On six different nights, different bats and a species of mouse have been additionally lively across the roosting tree. From the 9 samples containing solely the guano of the night bat, an astonishingly wealthy menu was then reconstructed: the group consumed at the very least 126 completely different species of moths, 86 completely different species of flies and mosquitoes, 48 species of beetles, and some dozen different varied species of bugs, mayflies, caddisflies, and lacewings. Often, spiders, harvestmen, lice, and different small animals have been additionally consumed.

From the outcomes, the workforce was capable of deduce which of the three molecular genetic markers used labored greatest and offered probably the most species detections, a complete of 358. “It’s incredibly satisfying to see what species lists come out at the end of all the lab work and bioinformatics,” says Dr. Sarah Bourlat, Head of the Metabarcoding Part at LIB, Bonn. Nevertheless, the temporal course of the composition of the consumed bugs was additionally attention-grabbing to watch: from late March to late June, the variety of species within the guano steadily will increase, solely to lower once more by mid-August. This aligns very properly with the exercise patterns of sure insect teams.

The beech moth was probably the most steadily consumed butterfly, and a mayfly often known as the transient virgin or ‘Uferaas’, was probably the most steadily consumed mayfly. The creator workforce has listed an important ecological parameters for the 18 key prey species within the research to contribute to raised defending the Leisler’s bat and the habitats wanted by its prey bugs.

Analysis article:
Bourlat SJ, Koch M, Kirse A, Langen Ok, Espeland M, Giebner H, Decher J, Ssymank A, Fonseca VG (2023) Metabarcoding dietary evaluation within the insectivorous bat Nyctalus leisleri and implications for conservation. Biodiversity Knowledge Journal 11: e111146. https://doi.org/10.3897/BDJ.11.e111146

Information announcement initially revealed by the Leibniz Institute for the Evaluation of Biodiversity Change. Republished with permission.

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