DOI: 10.5061/dryad.ghx3ffc0c
title: Multiple signaling increases both prey response and diversity in a carnivorous pitcher plant

description: Organisms across the tree of life use multiple signals such as color,
 movement, sound, and many types of chemical signals to convey seemingly
 the same information. These signals are potentially costly, yet the
 repeated evolution of multiple signaling across systems suggests an
 adaptive value. Using prey attraction by a carnivorous pitcher plant
 (Sarracenia purpurea), we tested two non-mutually exclusive hypotheses of
 how multiple signaling may be adaptive: 1) the receiver variability
 hypothesis that different signals reach different receivers, increasing
 the diversity of the receiver response and 2) the redundant
 signal hypothesis, that additional signals increase the probability of
 signal transmission to relevant receiver(s). We used artificial pitcher
 plant models with red coloration, nectar, and volatile organic compound
 signals to examine both the receiver variability and redundant signal
 hypotheses in a manipulative, full factorial field experiment in S.
 purpurea native habitat. Like pitcher plants, models captured visiting
 arthropods, which pitcher plants digest to cope with nutrient-poor bog
 soils. We found support for both the receiver variability and redundant
 signal hypotheses; both color and nectar additively increased prey
 diversity, as well as increased the capture of the bog specialist ant
 Myrmica lobifrons. Synthesis: Our results suggest that increasing both
 signal redundancy and diversity of respondents are substantial benefits
 that balance the costs of multiple signaling.
description: # Multiple signaling increases both prey response and diversity in a
 carnivorous pitcher plant ## Description of data and files Describes data
 from artificial pitcher plants (modeled off of *Sarracenia purpurea*)
 placed in 4 Michigan pitcher plant bogs in August 2023, as well as several
 follow up experiments conducted in the summer of 2024. Artificial pitcher
 plants contain a presence/absence full factorial of three putative prey
 attracting signals: red coloration, extrafloral nectar, and artificial VOC
 blends. Data on the spectral reflectence of real plants and painted models
 are also included in this dataset. ### Files Raw data files:
 **ColNectVol.csv** -- Abundance of each prey morphospecies in each model
 pitcher plant at each site. Includes only models that captured prey (see
 below). **colNectVolSetUp.csv** -- contains a unique row for each
 artificial pitcher plant placed at each bog site, regardless of prey
 capture outcome. Also lists field work dates. **contrast.csv** -- The
 background moss color where each artificial pitcher plant was placed at
 the Upper Manistee Headwaters Preserve Site for analysis of the influence
 of background contrast on prey capture. **gcms2024-05_normalized.csv** --
 GCMS peaks and calcaluated raw and normalized emission rates of each
 compound in the artifical VOC blend. Model pitcher plants were set up in a
 sunny, well ventilated greenhouse in the same way they were set up in the
 bog sites; silicone septa were soaked in VOC blend in DCM, then dried for
 1 hour before being hung inside artificial pitcher plants. Models were
 bagged and sampled for 30 minutes starting at the specified hour post set
 up. **ModelPreyProfile.csv** -- Abundance of each prey morphospecies in
 each model pitcher plant used to compare real plants and model plants.
 Includes only models that captured prey. **RealPlantPreyProfile.csv** --
 Abundance of each prey morphospecies in each real pitcher plant used to
 compare real plants and model plants. **Paint_RealPlant_Spectra.csv** --
 spectral reflectance data from real plants and painted model pitcher
 plants. **PosHocVOC.csv** -- Abundance of each prey morphospecies in each
 model pitcher plant used in the post hoc VOC experiment testing prey
 response to the high VOC blend, the biologically realistic blend, and a
 solvent (DCM) control. **Appendix A.zip** -- microscope images of each
 morphospecies referenced in ColNectVol.csv; also includes
 "InsectIDNotes.docx" file of descriptions of each insect, and
 the sample where that morphospecies was first identified.  Code:
 **MultipleSignalingAnalysis.Rmd** -- Code for data analysis and plots of
 main hypothesis testing, including only data from red and nectar
 treatments. **MultipleSignalingAnalysis.html** -- Knitted version of
 MultipleSignalingAnalysis.Rmd file
 **MultipleSignalingAnalysis_w_VOCs.Rmd** -- Code for data analysis and
 plots of main hypothesis testing, including all data (red, nectar, and VOC
 treatments) **MultipleSignalingAnalysis_w_VOCs.html** -- Knitted version
 of MultipleSignalingAnalysis_w_VOCs.Rmd **ModelValidation.Rmd** -- Code
 for data analysis and plots related to model validation, VOC lure and GCMS
 calculations, post hoc VOC experiments and spectra comparison
 **ModelValidation.html** -- Knitted version of ModelValidation.Rmd
 Glossary: **ColNectVol.csv** * trt -- the experimental treatment applied
 to each model; null is -nect - col - vol; the capital letters R N and V
 refer to the presence of each signal (Red veins, nectar, and VOCs,
 respectively) * rep -- replicate, or the microsite array each model was
 placed within. Replicates range from 1-30 at each site. * site -- the site
 where each model was placed; YSDL = Yankee Springs Deep Lake Yankee
 Springs Deep Lake boat launch (42.620, -85.457), * YSLL = Yankee Springs
 Long Lake (42.627, -85.505) * error -- 1 = some kind of error occured,
 including a tube lost or spilled during collection. Blank cells indicate
 no error * P -- the total number of prey items collected from each model
 pitcher plant; includes "NP" column (see below); used as an
 internal check during lab processing of samples * NP -- 'no
 prey'; 1 = no prey were found after examination under a microscope.
 Blank cells indicate prey was found * ref -- 1 = storage tube was removed
 from others as a morphospecies identification reference; blank cells
 indicate storage tube in main storage box * Unk2:spider -- number of items
 of that morphospecies, species, or larger taxonomic group found in the
 artificial pitcher plant. Blank cells indicate none of that taxon was
 found. See paper Supplement for morphospecies descriptions and images. *
 sarc -- the number of Fletcherymia fletcheri larvae (Sarcophagid flies
 specialist on pitcher plants phytotelmata) found in the artificial pitcher
 plant * notes -- notes **colNectVolSetUp.csv** * trt -- the experimental
 treatment applied to each model; null is -nect - col - vol; the capital
 letters R N and V refer to the presence of each signal (Red veins, nectar,
 and VOCs, respectively) * rep -- replicate, or the microsite array each
 model was placed within. Replicates range from 1-30 at each site. * site
 -- the site where each model was placed; YSDL = Yankee Springs Deep Lake
 Yankee Springs Deep Lake boat launch (42.620, -85.457), * KBSB = Kellogg
 Biological Station Sherman Farm Marsh (42.355, -85.372), UMHP = Upper
 Manistee Headwaters Preserve (44.745, -85.005) * and GRNA Grass River
 Natural Area (44.921, -85.242). * dateOut -- the date (month/day/year) the
 model was placed in the bog * dateIn -- the date (month/day/year) the
 model was retrieved from the bog * spill -- 1 = tube spilled during
 collection. Blank cells indicate no error * error -- 1 = some kind of
 error occured, including a tube lost. Blank cells indicate no error * tube
 -- 1 = an alcohol storage tube was created during initial sample
 processing: possible prey was visible in the bottom of the model plant. 0
 = no alcohol storage tube was created, model * considered to have captured
 no prey. The rows of the ColNectVol.csv sheet correspond to those rows of
 this sheet with a 1 in the tube column. * notes -- notes **contrast.csv**
 * trt -- the experimental treatment applied to each model; null is -nect -
 col - vol; the capital letters R N and V refer to the presence of each
 signal (Red veins, nectar, and VOCs, respectively) * rep -- replicate, or
 the microsite array each model was placed within. Replicates range from
 1-30 at each site. * site -- the site where each model was placed; UMHP =
 Upper Manistee Headwaters Preserve (44.745, -85.005) * sphCol -- the color
 of the Sphagnum moss where each artificial pitcher plant was placed;
 either 'red' or 'green' **gcms2024-05_normalized.csv**
 * sample -- the sample code; +0 and +3 refer to hours post drying time (1
 hour after removal from soaking solution) when the sample was taken * R1-5
 refer to replicate model pitcher plants 1 - 5, which were set up in a
 sunny greenhouse. EB refers to empty bag samples taken as a reference /
 control. * Missing replicates are due to failed sample elutions due to low
 elution volumes * time -- the time in hours post drying time (1 hour after
 removal from soaking solution) when the sample was taken * rep --
 replicate model pitcher plants 1 - 5; Missing replicates are due to failed
 sample elutions due to low elution volumes * eb -- sample was an empty bag
 samples taken as a reference / control * ocimene:total -- peak area for
 each compound, and the sum of all peak areas for the sample *
 ocimene_nghr:total_nghr -- the emission of each compound and the total
 emission for each sample, in nanograms per hour *
 ocimene_nghr_norm:total_norm -- the emission of each compound and the
 total emission for each sample (ng per hour), normalized by subtracting
 the emission of each compound found in the empty bag at that time point
 **ModelPreyProfile.csv** * trt -- the experimental treatment applied to
 each model; null is -nect - col - vol; the capital letters R N and V refer
 to the presence of each signal (Red veins, nectar, and VOCs, respectively)
 * rep -- replicate, or the microsite array each model was placed within.
 Replicates range from 1-30 at each site. * site -- the site where each
 model was placed; YSDL = Yankee Springs Deep Lake Yankee Springs Deep Lake
 boat launch (42.620, -85.457), * KBSB = Kellogg Biological Station Sherman
 Farm Marsh (42.355, -85.372), UMHP = Upper Manistee Headwaters Preserve
 (44.745, -85.005) * and GRNA Grass River Natural Area (44.921, -85.242). *
 spill -- 1 = tube was spilled during collection. NA indicates tube was not
 spilled * tube -- 1 = an alcohol storage tube was created during initial
 sample processing: possible prey was visible in the bottom of the model
 plant. 0 = no alcohol storage tube was created, model * considered to have
 captured no prey. * NP -- 'no prey'; 1 = no prey were found
 after examination under a microscope. NAs indicate prey was found. * ref
 -- 1 = storage tube was removed from others as a morphospecies
 identification reference; blank cells indicate storage tube in main
 storage box * unk3:ukn -- number of items of that morphospecies, species,
 or larger taxonomic group found in the artificial pitcher plant. Blank
 cells indicate none of that taxon was found. See paper Supplement for
 morphospecies descriptions and images. * notes -- notes
 **RealPlantsPreyProfile.csv** * plantID -- plant identifier; number is
 unique within a site, no correspondence between plants with the same ID at
 different sites. Number corresponds to replicate number of closest
 artificial pitcher plant replicate * initial_final -- i = initial, or prey
 collected when models placed in bog on day one of data collection
 (corresponds to diversity of prey capture over the previous weeks and
 months); f = final, prey collected from plant when model pitcher plants *
 were retrieved 24 hours later (corresponds to prey capture by real plants
 over the same time interval as the model pitcher plants) * site -- the
 site where each model was placed; YSDL = Yankee Springs Deep Lake Yankee
 Springs Deep Lake boat launch (42.620, -85.457), * KBSB = Kellogg
 Biological Station Sherman Farm Marsh (42.355, -85.372), UMHP = Upper
 Manistee Headwaters Preserve (44.745, -85.005) * and GRNA Grass River
 Natural Area (44.921, -85.242). * spill -- 1 = tube was spilled during
 collection. NA indicates tube was not spilled * NP -- 'no prey';
 1 = no prey were found after examination under a microscope. NAs indicate
 prey was found. * globSpring:unk -- number of items of that morphospecies,
 species, or larger taxonomic group found in the artificial pitcher plant.
 Blank cells indicate none of that taxon was found. See paper Supplement
 for morphospecies descriptions and images. **PostHocVOC.csv** * trt -- the
 experimental treatment applied to each model; null is -nect - col - vol;
 the capital letters R N and V refer to the presence of each signal (Red
 veins, nectar, and VOCs, respectively) * rep -- replicate, or the
 microsite array each model was placed within. Replicates range from 1-30
 at each site. * tube -- 1 = an alcohol storage tube was created during
 initial sample processing: possible prey was visible in the bottom of the
 model plant. 0 = no alcohol storage tube was created, model * considered
 to have captured no prey. * finished -- internal check that tube was
 processed (sum of notube, NP, and prey taxon columns) * notube -- 1 = no
 alcohol storage tube was created; NA indicates a storage tube was created
 * NP -- no prey, 1 = after examination under a microscope, no prey items
 were found; NA indicates prey was found, or no alcohol storage tube was
 created * unknown:snail -- abundance of each category of prey * notes --
 notes * sum -- total count of all prey captured * bin -- binary prey
 capture; 1 = some kind of prey captured, 0 = no prey was captured
 **Paint_RealPlant_Spectra.csv** -- spectral reflectance data from real
 plants and painted model pitcher plants * wl -- the sampling wavelength,
 in nm * redPaint -- samples of red areas of painted models
 ('Burgundy', Plaid acrylic paint); columns include three samples
 (1-3) and three measurements per sample * greenPaint -- samples of green
 areas of painted models ('Fresh Foliage', Plaid acrylic paint);
 columns include three samples (1-3) and three measurements per sample *
 All other columns named with the following conventions: * rd010, rd014,
 and rd002 all refer to individual pitcher plants growing in the Gilbert
 Lab green house living collection * 'vase' refers to the tubular
 body of the pitcher (colored red in all sampled plants) *
 'grSpot' refers to a green area of the inner hood of the pitcher
 leaf * 'rdSpot' refers to a red area of the inner hood of the
 pitcher leaf * 'young' modifies some samples to indicate the
 leaf was young and not fully pigmented or lignified Each sample was
 measured three times, with the columns bearing identical names. Suffixes
 "", ".1", and ".2" differentiate between
 three replicate measurements for each sample. Required packages:
 tidyverse, glmmTMB, performance, DHARMa, brms, tidybayes, vegan, pavo,
 viridis, ggpubr