DOI: 10.5061/dryad.zs7h44jn3
title: Effects of fruit novelty on feeding preference in four globally invasive frugivorous birds

description: Invasive fruit-eating animals (hereafter frugivores) can form novel
 mutualisms with fruiting plants and alter seed dispersal. Plant-frugivore
 interactions are often linked to frugivore preference for certain fruit
 traits, but for invasive frugivores, it is uncertain if novelty—whether or
 not a fruit is familiar—impacts foraging decisions. We experimentally
 tested fruit preferences of the four most abundant and frugivorous bird
 species on O‘ahu, a Hawaiian Island, all of which are globally invasive
 songbirds. With captive wild birds, we tested for preference in relation
 to fruit size, color, nutrients, and bird sex. We also tested how novelty
 of fruits affected trait-based preferences, with fruits from plant species
 either established in the wild or novel. Using arrays that offered
 multiple fruit species, we conducted 252 trials with 111 plant species,
 59.5% of which were considered novel. From all fruits tested, three bird
 species preferred smaller fruits, and color preferences varied among bird
 species. Novelty of fruits influenced preference in three ways. First,
 birds preferred fruits from plants that were established in the wild over
 novel fruits. Second, repeated exposure to novel fruits increased the
 probability of interactions. Third, preferred novel fruits were smaller
 and redder than preferred fruits from established plants. Finally, bird
 sex and fruit nutrient content did not affect preference. Together, these
 results suggest that preference for fruit traits varies among invasive
 bird species and can be flexible when fruits are novel to birds,
 increasing the likelihood of novel mutualisms and making it increasingly
 difficult to predict invasion impacts.
description: # Effects of fruit novelty on feeding preference in four globally invasive
 frugivorous birds Dataset DOI:
 [10.5061/dryad.zs7h44jn3](10.5061/dryad.zs7h44jn3) ### Files and variables
 #### File: Biol.Inv_Case.etal_2024_Dryad.csv ##### Variables * TRIAL ID:
 Experimental trial * BIRD SPP: Bird species (four-letter code based on
 common name). See Table 3 of manuscript for full bird species names * BIRD
 ID: Bird individual * BIRD SEX: Bird sex (F=Female, M=Male) * DATE: Trial
 date * PLANT SPP: Plant species written as six-letter codes (first three
 letters of genus and first three letters of species, UNK and XXX=unknown)
 for plant species used in experiments. See Table 5 in manuscript for full
 plant species names * EXPOSURE: Exposure (the number of trials in which an
 individual bird had been offered fruit from a given plant species (e.g.,
 exposure of 1 is the first time a fruit was offered to a bird species,
 while an exposure of 6 is the sixth time a fruit was offered to a bird
 species) * INTERACTION: Events where at least one fruit was consumed (in
 part or whole) or removed from its toothpick) are classified as 1. Events
 where no interactions occurred are classified as 0.  * NOVELTY: Species
 were considered established (1) if they were native or nonnative species
 with established wild populations in Hawaiian forests. Plant species were
 considered novel (0) if they were occurring as a single individual or
 group of individuals within horticultural collections. * F.LENGTH: Fruit
 length (mm), estimate for plant species * F.WIDTH: Fruit width (mm),
 estimate for plant species * F.HEIGHT: Fruit height (mm), estimate for
 plant species * S.LENGTH: Seed length (mm), estimate for plant species *
 S.WIDTH: Seed width (mm), estimate for plant species * S.HEIGHT: Seed
 height (mm), estimate for plant species * SEED.NUM: Seed number, estimate
 for plant species * COLOR: Peak spectral reflectance (nm), estimate for
 plant species * LIPID: Lipid content (%), estimate for plant species *
 PROTEIN: Protein content (%), estimate for plant species * CARB:
 Carbohydrate content (%), estimate for plant species