DOI: 10.5061/dryad.x95x69pxj
title: Experimental evidence of a consistent commensal relationship between avian hosts and feather mites of differing host specificities

description: The majority of research on birds and their symbionts has focused on
 putatively parasitic relationships, but this presumption often lacks
 experimental evidence and overlooks the potential for context-dependent
 patterns. Nearly all studies regarding the impact of feather mites on
 their avian hosts have been correlative and spatially or taxonomically
 limited, resulting in conflicting and narrow classifications of the nature
 of the symbiosis (i.e., parasitic, mutualistic, or commensal).
 Furthermore, gaps in understanding mite host specificity, and thus an
 inability to account for this ecologically and evolutionarily important
 trait, may also contribute to these varying conclusions. Here, we examined
 the impacts of this trait by experimentally removing feather mites from
 two species of wild wood-warblers that harbor mites with different host
 specificities (one host specific, one found on ≥17 host species). Birds
 were recaptured the following year to assess potential for
 context-dependent impacts of mites on host body condition and apparent
 annual survival. Our treatment (mite removal) did not impact either metric
 and thus supports the neutral effect (commensalism) of feather mites on
 both Setophaga cerulea (Cerulean Warblers; host of the generalist mite,
 Amerodectes ischyros) and Protonotaria citrea (Prothonotary Warblers; host
 of the specialist mite, A. protonotaria). We found that mite abundances on
 S. cerulea, but not P. citrea, rebounded on hosts after one year despite
 experimental manipulation, so it is unclear how long our treatment lasted.
 This population rebound also indicates the need to better understand basic
 life history of feather mites (e.g., reproductive or transmission rate).
 This study provides some of the only experimental data on this perplexing
 symbiosis as well as a preliminary assessment of the importance of host
 specificity on the functional nature of this symbiotic relationship.
description: # Experimental evidence of a consistent commensal relationship between
 avian hosts and feather mites of differing host specificities Dataset DOI:
 [10.5061/dryad.x95x69pxj](10.5061/dryad.x95x69pxj) ## Description of the
 data and file structure Experimental removal of feather mites from two
 species of warblers conducted in the field to experimentally test the
 functional impact of mites on host body condition and survival, as well as
 measure the population rebound of mites year to year. ### Files and
 variables #### File: ExperimentalRemovalData-20240802.csv
 **Description:**  ##### Variables * name: nickname of the individual bird
 * species: PROW = Prothonotary Warbler; CERW = Cerulean Warbler *
 treatment: 1 = mites removed; 0 = control * color_combo: color band
 combination in format `top left/bottom left:top right/bottom right`; SI =
 silver USGS band; NB = no band; RD = red; GR = green; PI = pink; OR =
 orange; BL = blue; YE = yellow; WH = white * band_num: USGS band
 combination * site: site name location * dist_to_river_m: distance of
 banding location to river in m (for CERW only) * sex: M = male; F = female
 * batch: batch1 = first year samples; batch2 = second year samples *
 capture_year: year of capture * capture_month: month of capture *
 capture_day: day of capture * capture_date: combination of previous 3
 columns (date of capture) * capture_time: time of capture * capture_lat:
 latitude of capture * capture_lon: longitude of capture * capture_age: age
 upon capture (SY = second year; ASY = after second year; 3Y = third year;
 A3Y = after third year) * capture_age_SYASY: age upon capture, anything
 &gt;=ASY in `capture age` column is set to ASY (i.e., 3Y and A3Y are
 recoded as ASY) * capture_mass: mass upon capture (g) * capture_fat: fat
 score upon capture ( based on MAPS [Monitoring Avian Productivity and
 Survivorship] banding codes, which is a 0-7 scale [0 being 'no fat
 anywhere' to 7 being 'excessive']). NA if fat score was not
 assessed when processing the bird. * capture_wing: wing chord upon capture
 (mm) * capture_total_mites_estimate: total number of mites upon capture *
 release_total_mites_estimate: total number of mites upon release (should
 be 0 for treated birds; for control birds, should be the same as
 capture_total_mites_estimate * return: whether or not a bird returned the
 following year (1 = yes; 0 = no) * resight_year: year of first resight *
 resight_month: month of first resight * resight_day: day of first resight
 * resight_date: combination of previous 3 columns (date of first resight)
 * resight_lat: latitude of resight * resight_lon: longitude of resight *
 recapped: whether or not a resighted bird was recaptured or not (1 = yes,
 0 = no) * recapture_year: year of recapture * recapture_month: month of
 recapture * recapture_day: day of recapture * recapture_date: combination
 of previous 3 columns (date of recapture) * recapture_time: time of
 recapture * recapture_lat: latitude of recapture * recapture_lon:
 longitude of recapture * recapture_age: age upon recapture *
 recapture_mass: mass at recapture (g) * recapture_fat: fat score at
 recapture * recapture_wing: wing chord at recapture (mm) *
 recapture_total_mites_estimate: total number of mites upon capture *
 recapture_feather_collected_microbes: whether or not a feather was
 collected upon recapture for a separate project (R3 if yes, NA if no) *
 return_year3: whether or not a first batch (batch1) bird was seen
 (returned) on the 3rd year of fieldwork (when we were looking for batch2
 bird returnees) * resight_year_year3: year of resight for 3rd year of
 fieldwork * resight_month_year3: month of resight for 3rd year of
 fieldwork * resight_day_year3: day of resight for 3rd year of fieldwork *
 resight_date_year3: combination of last three columns (date of resight for
 3rd year of fieldwork) * resight_lat_year3: latitude of resight for 3rd
 year of fieldwork * resight_lon_year3: longitude of resight for 3rd year
 of fieldwork #### File: ExperimentalRemoval-20250704-topost.R
 **Description:** R script to run all analyses and generate figures ##
 Code/software R version 4.3.1 (2023-06-16) -- "Beagle Scouts"
 p_load("dplyr", "ggplot2", "ggpubr",
 "tidyr", "tidyverse", "reshape2",
 "ggthemes", "lubridate", "smatr",
 "lme4", "AICcmodavg", "glmulti",
 "sjPlot", "ggeffects", "effects",
 "lmerTest", "plyr", "ordinal",
 "emmeans", "ggforce") ## Access information Other
 publicly accessible locations of the data: *
 [https://github.com/alixmatthews/mite_removalexp_2021-2023](https://github.com/alixmatthews/mite_removalexp_2021-2023)