DOI: 10.5061/dryad.ns1rn8pvt
title: Predation on artificial caterpillars following understorey fires in human-modified Amazonian forests

description: Tropical forests are facing several impacts from anthropogenic
 disturbances, climate change and extreme climate events, with potentially
 severe consequences for ecological functions, such as predation on
 folivorous invertebrates. Folivory has a major influence on tropical
 forests by affecting plant fitness and overall seedling performance.
 However, we do not know whether predation of folivorous arthropods by
 birds, mammals, reptiles and other arthropods is affected by anthropogenic
 disturbances such as selective logging and forest fires. We investigated
 the impacts of both pre-El Niño human disturbances and the 2015-2016 El
 Niño understorey fires on the predation of 4,500 artificial caterpillars
 across 30 Amazonian forest plots. Plots were distributed in four pre-El
 Niño forest classes: undisturbed, logged, logged-and-burned and secondary
 forests, of which 14 burned in 2015-16. We found a higher predation
 incidence in forests that burned during the El Niño in comparison to
 unburned ones. Moreover, logged-and-burned forests that burned again in
 2015-16 were found to have significantly higher predation incidence by
 vertebrates than other forest classes. However, overall predation
 incidence in pre-El Niño forest disturbance classes was similar to
 undisturbed forests. Arthropods were the dominant predators of artificial
 caterpillars, accounting for 91.5% of total predation attempts. Our
 results highlight the resilience of predation incidence in human-modified
 forests, although the mechanisms underpinning this resilience remain
 unclear.
description: Predation experiments were conducted between April 10 and June 15
 2019, corresponding to the middle-end of the wet season. All artificial
 caterpillars were green, made from odourless non-toxic coloured plasticine
 (Lewis NewplastTM) mixing an equal portion of dark and light green to
 create medium green coloured caterpillars. Artificial caterpillars were
 crafted to mimic cryptic Lepidoptera larvae. We fixed the caterpillars to
 the vegetation by passing a wire longitudinally through them. When placing
 caterpillars in the field, we removed all handling marks to avoid
 misidentifying them with predator’s marks.  We
 established five 20 × 5 m sub-plots within each of the 30 forest plots. We
 placed 30 caterpillars in each sub-plot, totalling 150 caterpillars per
 forest and 4,500 caterpillars across the experiment. All caterpillars were
 installed on understorey vegetation branches, between 1.0 – 4.5 m from the
 ground, separated by at least 1 m from each other. We evaluated predation
 in the understorey due to the difficulties of placing caterpillars in the
 tall canopy (i.e., 30-50 m). After 14 days of field exposure, a single
 observer (LCR) recovered all caterpillars and assessed whether they had
 been predated, attributing predation marks to different predator groups.
 The identification of predation marks on recovered caterpillars was based
 on the beak, mandibular tooth or radula marks. The predation marks were
 attributed to one of four predator groups: arthropods, birds, reptiles and
 mammals. Multiple marks made by the same type of predator on a single
 caterpillar were categorized as a single predation event. 
description: # Predation on artificial caterpillars following understorey fires in
 human-modified Amazonian forests # forest\_class The
 'forest_class' column categorizes the forest plots based on four
 types of pre-El Niño human-modified forest conditions. These
 classifications are as follows: * **UF (Undisturbed Forests)**: Forests
 that have not been subjected to human disturbance. * **LF (Selective
 Logged)**: Forests that have experienced selective logging, where only
 certain trees were removed. * **LBF (Logged-and-Burned)**: Forests that
 have undergone both logging and subsequent burning. * **SF (Secondary
 Forests)**: Forests that have regrown following a disturbance, such as
 logging or agriculture, and are in the process of ecological succession.
 These classifications are used to assess the impact of different
 disturbance levels on forest ecosystems. # fire\_2015 The '2015–2016
 El Niño affected forests' classification differentiates forest plots
 based on whether they were affected by fires during the 2015–2016 El Niño
 event. Here's the description: * **0 (Unburned Forests)**: Forests
 that did not burn during the 2015–2016 El Niño event. * **1 (Burned
 Forests)**: Forests that burned during the 2015–2016 El Niño event. #
 trans\_code The 'trans_code' column represents the unique code
 assigned to each of the 30 forest study plots. Each code identifies a
 specific plot used in the research. # trans\_code\_sp The
 'trans_code_sp' column represents the codes assigned to
 sub-plots within each forest plot. Each of the 30 forest plots measures
 250 x 10 meters (0.25 hectares) and contains five sub-plots, each
 measuring 20 x 5 meters. The codes in this column follow a pattern based
 on the distance from the start of the forest plot, with the number
 reflecting the center point of each sub-plot (measured in meters).
 Here's the breakdown of the sub-plot codes: * **SP25**: Sub-plot
 centered at 25 meters * **SP75**: Sub-plot centered at 75 meters *
 **SP125**: Sub-plot centered at 125 meters * **SP175**: Sub-plot centered
 at 175 meters * **SP225**: Sub-plot centered at 225 meters These codes
 help to precisely locate and differentiate the sub-plots within each
 forest plot. # number The 'number' column refers to the unique
 identifier assigned to each caterpillar within the forest plots, ranging
 from 1 to 150. This numbering system helps track individual caterpillars.
 # caterpillar\_cod The 'caterpillar_cod' column represents a
 unique identifier for each caterpillar, created by combining three
 elements: 1. **trans_code**: The code for the forest plot. 2.
 **trans_code_sp**: The code for the sub-plot within the forest plot. 3.
 **number**: The individual caterpillar's number within that plot.
 This combination ensures that each caterpillar in the study has a distinct
 code, making it possible to accurately track and reference caterpillars
 across different plots and sub-plots. # predation The
 'predation' column indicates the presence or absence of
 predation marks on the caterpillars. The values are coded as follows: *
 **0 (Absence)**: No predation marks were observed on the caterpillar. *
 **1 (Presence)**: Predation marks were observed on the caterpillar. #
 arthropod The 'arthropod' column indicates whether caterpillars
 were predated by arthropods. The values are coded as follows: * **0
 (Absence)**: No evidence of predation by arthropods. * **1 (Presence)**:
 Evidence of predation by arthropods was observed. # vertebrate The
 'vertebrate' column indicates whether caterpillars were predated
 by vertebrates, including birds, mammals, and reptiles. The values are
 coded as follows: * **0 (Absence)**: No evidence of predation by
 vertebrates. * **1 (Presence)**: Evidence of predation by vertebrates was
 observed. # bird The 'bird' column indicates whether
 caterpillars were predated by birds. The values are coded as follows: *
 **0 (Absence)**: No evidence of predation by birds. * **1 (Presence)**:
 Evidence of predation by birds was observed. # mammal The
 'mammal' column indicates whether caterpillars were predated by
 mammals. The values are coded as follows: * **0 (Absence)**: No evidence
 of predation by mammals. * **1 (Presence)**: Evidence of predation by
 mammalswas observed. # reptile The 'reptile' column indicates
 whether caterpillars were predated by reptiles. The values are coded as
 follows: * **0 (Absence)**: No evidence of predation by reptiles. * **1
 (Presence)**: Evidence of predation by mammalswas reptiles. # lost and
 excluded The 'lost and excluded' column refers to caterpillars
 that were removed from the analyses due to being unrecovered or lost
 during the study.