DOI: 10.5061/dryad.wstqjq2xz
title: Effects of herbivore-induced plant volatiles on behaviors and reproduction in a common songbird

description: In insectivorous birds the reproductive period often coincides with the
 spring development of vegetation, but whether there is a direct
 relationship between the two, and through which mechanisms this link could
 come about, is not clear. Trees release herbivore-induced plant volatiles
 (HIPVs) when they are attacked by insects, and we test here whether birds
 use those alarm odors to modulate their behaviors and their reproduction.
 Using a two-step experimental approach, we first show in controlled
 conditions that blue tits are attracted to HIPVs mimicking a caterpillar
 attack on downy oak buds in early spring, without having to learn them. We
 then equipped nest-boxes in the field with the same artificial HIPVs. We
 did not find that birds that built their nest in HIPV nest-boxes advanced
 lay dates or produced larger clutches. However, although this result was
 not statistically significant, slightly more nest-boxes equipped with
 HIPVs were occupied compared to control ones, resulting in significantly
 more eggs, nestlings, and fledglings introduced in the population from
 these treated nest-boxes. Our results thus show that blue tits innately
 detect and track subtle plant olfactory signals, while the link with
 reproductive decisions appears more tenuous and requires further
 investigations. Such a link with reproduction is nevertheless in line with
 recent studies showing that HIPVs can stimulate the reproductive
 physiology of songbirds, and highlights new multitrophic interactions
 across plants, insects, and birds, an encouraging area of study for
 understanding adaptations to a constantly changing environment.
description: # Effects of alarm odors from trees on behaviors and reproductive
 decisions in a common songbird GENERAL INFORMATION This README file was
 updated on 8/12/2025 by Segolene Delaitre A. Paper associated with this
 archive Citation: Effects of herbivore-induced plant volatiles on
 behaviors and reproduction in a common songbird, Delaitre, Ségolène; Caro,
 Samuel P.; Graham, Jessica L.; Buatois, Bruno B. Originators Delaitre,
 Ségolène1; Caro, Samuel P. 1; Graham, Jessica L. 2; Buatois, Bruno 1 1\.
 Centre d'Écologie Fonctionnelle et Évolutive 2\. Black Hills State
 University C. Contact information Caro, Samuel P.
 [samuel.caro@cefe.cnrs.fr](mailto:samuel.carp@cefe.cnrs.fr) D. Dates of
 data collection From 2019 to 2022 E. Geographic Location(s) of data
 collection Blue and great tit reproduction was monitored in a deciduous
 downy oak (Quercus humilis) forest on the mainland near Montpellier (La
 Rouvière wood, Montarnaud, 43.621°, 3.733°). The Y-maze experiment took
 place at the CEFE-CNRS in Montpellier, France. F. Funding Sources This
 work was funded by a grant from the Agence Nationale de la Recherche
 (awarded to SPC). DATA & CODE FILE OVERVIEW This data repository
 consist of 5 data files, 1 code script, and this README document, with the
 following data and code filenames and variables Data files and variables
 "Metadata for tab ""naivetest.csv""" This
 dataset contains the data for the behavioural experiment in the Y-maze.
 Column Entry Explanatation * A birdID identification of the birds - B sex
 Sex of the birds * C explo Exploration score of the birds - D Treatment
 Treatment of the arms of the maze (Control, Neutral or HIPV) * E side1
 First side chosen by the birds (1 if the birds choose the HIPV arm first,
 0 otherwise) - F code1 Variable to select only 1 row per bird * G time
 Time spent in the arm (in seconds) - H dish Number of dishes visited in
 the arm * I wind Variable summarizing the wind direction and speed at the
 time of the test The 4 following datasets contains the 2019-2020 data for
 the field experiment. "Metadata for tab
 ""NA1BC.csv""" Column Entry Explanatation * A
 population Population of the birds (rou = Mainland, corse = Corsica - B
 year Year of the data * C nestboxID Identification of the nestboxes - D
 treatment Treatment of the nestboxes * E laydatecode Code of the laying
 date (1 = 1st january) - F eggnb Clutch size * G fledgenb Number of
 fledglings - H success_fledge_hatch Number of fledglings/number of
 hatchlings * I fbag Identification of the female that laid in this nestbox
 "Metadata for tab ""countsrouv1920.csv"""
 This dataset contains the data of 2019 and 2020 on the Mainland. Column
 Entry Explanatation * A year Year of the data - B Treatment Treatment of
 the nestboxes * C occu Total number of nestboxes occupied - D nbegg Total
 number of eggs laid * E nbchicks Total number of 15 days old nestlings
 produced - F nbfledge Total number of fledglings produced "Metadata
 for tab ""countsrouvcorse20.csv""" This dataset
 contains the data of 2020 on the Mainland and in Corsica. Column Entry
 Explanatation * A population Population of the birds (rou = Mainland,
 corse = Corsica - B Treatment Treatment of the nestboxes * C occu Total
 number of nestboxes occupied - D nbegg Total number of eggs laid * E
 nbchicks Total number of 15 days old nestlings produced - F nbfledge Total
 number of fledglings produced "Metadata for tab
 ""chicks.csv""" Column Entry Explanatation * A
 population Population of the birds (rou = Mainland, corse = Corsica - B
 year Year of the data * C nestbox Identification of the nestboxes - D
 Treatment Treatment of the nestboxes * E fbag Identification of the female
 that laid in this nestbox - F weight Weight of the chichks R script
 description (Rscript.R) The R script contains all the code for the
 analysis of the Y maze experiment and the field experiment described in
 the paper.  SOFTWARE VERSIONS All the analyses were performed in R version
 1.3.1093 (R Core Team 2022). Linear mixed-effects models and generalized
 linear mixed-effects models were conducted using the lme4 package.
 P-values were obtained with the lmerTest package in the case of
 mixed-model analyses. Effect sizes were obtained with the effectsize
 package. Plots were created with the ggplot2 package. Post-hoc tests were
 conducted using the lsmeans package.