DOI: 10.5061/dryad.bzkh189jr
title: Birds and bats reduce herbivory damage in Papua New Guinean highland forests

description: Insectivorous predators, including birds and bats, play crucial roles in
 trophic cascades. However, previous research on these cascades has often
 relied on permanent predator exclosures, which prevent the isolation of
 specific effects of birds and bats, given their different activity
 patterns throughout the day. Moreover, limited knowledge exists regarding
 the variations in individual effects of these predators under different
 biotic and abiotic conditions, such as changes in elevation. To address
 these uncertainties, our study aimed to investigate the distinct effects
 of bats and birds on arthropod densities in foliage and herbivory damage
 in lowland and highland rainforests of Papua New Guinea (PNG). Predator
 exclosures were established for one month to exclude diurnal or nocturnal
 predators across 120 saplings (ca. 2.5-4 m tall) selected from two lowland
 and two highland forests (i.e., 30 saplings per study site) along the Mt.
 Wilhelm transect in PNG. Arthropods were collected and measured, and
 herbivory damage was analysed at the end of the experiment. Birds
 significantly reduced arthropod densities by 30 %, particularly in
 arthropods longer than 10 mm, regardless of elevation. Additionally, both
 birds and bats appeared to mitigate herbivory damage in highland forests,
 with protected saplings displaying up to 189 % more herbivory. Our results
 support previous studies that have demonstrated the ability of
 insectivorous predators to reduce leaf damage through the control of
 arthropods. Furthermore, our approach highlights the importance and
 necessity of further research on the role of seasons and elevations in
 trophic cascades.
description: We conducted predator exclosure experiments at four elevational
 study sites along the Mt. Wilhelm elevational gradient in Papua New
 Guinea. The experiments were carried out on 120 saplings from 11 tree
 species. The predator exclosures, constructed from PVC tubes and
 agricultural nylon netting, were used to individually exclude birds and
 bats from the saplings. Each exclosure was accompanied by control
 saplings. After one month of exclusion, we collected all arthropods from
 the saplings to estimate their densities and sizes and assessed the extent
 of herbivory damage. We compared the experimental outcomes with the
 richness and abundance of vertebrate predators (birds and bats) using
 previously published data from this location.
description: # Birds and bats reduce herbivory damage in Papua New Guinean highland
 forests
 [https://doi.org/10.5061/dryad.bzkh189jr](https://doi.org/10.5061/dryad.bzkh189jr) Here are the two main important datasets used throughout the manuscript. Arthropods_Density&Size.xlsx shows the total arthropod density and size per sample found in our study as well as the densities partitioned into four feeding guilds: NR (no relationship), Sapsuckers, Herbivores, and Predators. Herbivory_LeafArea.xlsx presents the herbivory estimations found for each sapling in our study. ### Description of Arthropods\_Density\&Size.xlsx * Code: ID of the tree individual (sapling) * Plant_name: Tree species * Elev: Elevation of the study site (m) * Treatment: Name of each treatment (CON: controls, BIR: Bird exclusions, BAT: Bat exclusions) * NoRelationship: Number of collected NR arthropods (Arthropods with No Relationships with herbivory or other predators)  * Predators: Number of collected Predatory arthropods * CHEW: Number of collected herbivorous arthropods * SUC: Number of collected sapsucking arthropods * Total: Total number of collected arthropods  * TotalAbundance: Total density of arthropods (abundance of arthropods / mean leaf area) * TotAbundPred: Density of predatory arthropods * TotAbundNR: Density of NR arthropods * TotChew: Density of herbivorous arthropods * TotSap: Density of sapsucking arthropods * Leafarea: Mean area of the leaves (m²) * SizeTot: Mean size of arthropods (mm) ### Description of Herbivory\_LeafArea.xlsx * Sample: ID of the tree individual (sapling) * Elev: Elevation of the study site (m) * Treatment: Name of each treatment (CON: controls, BIR: Bird exclusions, BAT: Bat exclusions) * Plant_species: Tree species * HerbivoryProp : Herbivory estimation (%) * TotalAreaM2: Estimation of the total leaf area of the corresponding sapling (average in m2)