Dataset: A. pisonii: herbivory
Deployment: Griffen_mangroves

We established three random 10 m x 10 m plots within a dwarf Rhizophora mangle stand in Twin Cays, Belize. In each plot, we established the X, Y coordinates of each tree within the plot by determining the position of its central trunk. We measured morphological tree characteristics for each tree, including length (m, long axis of the tree), width (m, short axis of the tree), and height (m). Additionally, we categorized all trees into one of three categories: (1) no refuge, (2) adjacent to refuge, (3) refuge. Trees categorized as “no refuge” did not contain a tree hole resulting from previous herbivory by the beetle Elaphidion mimeticum (Cerambycidae) or other wood-boring insects. Trees categorized as “adjacent to refuge” did not contain a tree hole, but were physically in contact with a tree that did contain a tree hole. Trees categorized as “refuge” contained a tree hole.

Within each of the three experimental plots, we randomly selected five trees from each of the three tree categories (except plot 3, in which there were only four “adjacent to refuge” trees). For each of these trees (n=44), we randomly collected 10 green leaves from a basal position on a twig (i.e. fourth or fifth leaf pair from the twig terminals).  Leaves were transported to the field station on Carrie Bow Cay and pinned flat. We then digitally photographed all 10 leaves from each tree in one frame, along with a size reference for use in subsequent leaf image analysis.

In order to analyze the proportion of leaf area damaged or removed by herbivory, we used the digital analysis software ImageJ 1.49u (U.S. National Institutes of Health). For each image, which included the 10 leaves collected from a single tree, we first set the scaling factor using the size reference. We outlined the total area of a single individual leaf to quantify total leaf area (cm²), and then proceeded to outline each individual area (cm²) on the leaf surface that showed evidence of complete herbivory (sections of leaf completely removed) or damage from herbivory (partial removal of leaf, such as scraping or brown areas). For each of these instances of leaf damage, we used recognizable leaf damage signatures of the three herbivores that damaged leaves in this study ((1) the mangrove tree crab Aratus pisonii, (2) the mangrove periwinkle snail Littoraria angulifuera, and (3) larvae of the bagworm moth Oiketicus kirbii) to categorize which was responsible for each piece of leaf damage. After determining the total area of all spots damaged by herbivory on a single leaf, we calculated the percentage of leaf area that was damaged or consumed by herbivory for each of the three herbivores, as well as the total percentage of leaf area damaged or consumed by all herbivores. We then repeated the process for the nine remaining leaves in the image, beginning with the outline of the next leaf’s total leaf area.