DOI: 10.5281/zenodo.17093465
title: BETA-FOR_SP9_Predation_2022-2025

description: one-time sampling + rapid assessment 2023 - 2025

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This dataset contains predation data on artificial caterpillars collected between 2022 and 2025. In 2022, sampling was conducted in 90 patches within the University Forest and 90 patches in the Bavarian Forest. In 2023, 54 patches located in Saarland, Hunsrück, and Lübeck were sampled, along with the rapid assessment sites, which continued to be sampled through 2025.

In each patch, 21 artificial caterpillars were installed following a standardized protocol. Seven trees were selected per patch, as close as possible to the patch center. In patches with forest gaps, trees from the first tree line were chosen. Selected trees had to have a branch with leaves at a height of approximately 1.70 m. Three caterpillars were placed on each tree, using non-toxic glue (PRITT Bastelkleber, (SKU/IDH)2463962) to attach them to the bark: one on the ground, one on the stem at a height of 0.5 to 1 m, and one on a branch at a height of 1.50 to 2 m.

The caterpillars were exposed for one week at the end of June, when weather conditions were mostly dry and not too windy. Due to unfavorable weather conditions in June 2025, the experiment at the rapid assessment sites in the Bavarian Forest and Passau was repeated in July 2025. However, this experiment includes more dropped caterpillars than the June 2025 sampling. After exposure, bite marks were analyzed in the lab using a custom bite guide developed by Murat Demirok, as well as existing references, including Low et al. (2014) and the Guide to Bite Marks by Tvardikova & Novotny (2012). Predator groups were recorded as present or absent (0/1) for each caterpillar. If multiple predators were identified, they were listed in separate columns for the same caterpillar.

The artificial caterpillars were made from green, non-toxic plasticine (Plastilin-Knete Noris® 8421, STAEDTLER). They were shaped with a diameter of 5 mm and a length of 25 mm, with rounded edges, reaching a maximum length of approximately 30 mm.

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We greatly acknowledge the help of:

Jens Schlüter, Camilla Haider, David Ritz, Adèle Kieffer, Jorge Torres, Kim Zimmermann, Hans Bahr, Noelle Demuth, Jean-Léonard Stör, Interns of the Bavarian Forest Nationalpark and all other assistants.
description: Variables Description################

*patchLabelBETAFOR: unique BETA-FOR patch label

*region: region in which the patch is located

*district: abbreviation for the district in which the patch is located

*treatment: abbreviation for the treatment performed on the patch

*dwc:decimalLongitude: longitudinal coordinates of the patch in decimals

*dwc:decimalLatitude: latitudinal coordinates of the patch in decimals

*elevation: elevation above sea level of the patch

*dwc:year: year when the recording was performed

*treeID: number of the tree in the patch, numeric from 1 to 7

*positionOnTree: position of the caterpillar on the tree is indicated with T=top, M=middle, G=ground

*caterpillarID: unique identifier for each caterpillar within a given year

In the following columns, NA denotes instances where the caterpillar was either not found or could not be identified after collection due to insufficient labeling.

*caterpillarFound: 1 if caterpillar was found again after the exposure period, 0 if not.

*caterpillarDropped: 1 if caterpillar was dropped from its original position on the tree during the period of exponation, 0 if not. 

*predation: 1 if marks of at least one predator were visible, 0 if not. 

*aves: 1 if marks of predation caused by birds were visible, 0 if not.

*mammals: 1 if marks of predation caused by mammals were visible, 0 if not.

*predatoryArthropods: 1 if marks of predation caused by at least one predatory arthropod were visible, 0 if not.

*beetles: 1 if marks of predation caused by beetles were visible, 0 if not.

*centipedeMilipede: 1 if marks of predation caused by centipedes or millipedes were visible, 0 if not. 

*grasshoppers: 1 if marks of predation caused by grashoppers were visible, 0 if not.

*ants: 1 if marks of predation caused by ants were visible, 0 if not.

*unknownPredatoryArthropods: 1 if marks of predation caused by unknown predatory arthropods were visible, 0 if not. 

*decomposers: 1 if marks of at least one decomposer were visible, 0 if not.

*gastropods: 1 if marks of gastropods were visible, 0 if not. 

*woodlice: 1 if marks of woodlices were visible, 0 if not. 

*unknowAnimalMarks: 1 if marks of unknown animals were visible, 0 if not. 

*notes: notes providing special information about the observation

*dwc:identifiedBy: name of the person who identified the marks on the caterpillars