Vocal signals such as calls play a crucial role for survival and successful reproduction, especially in group-living animals. However, call interactions and call dynamics within groups remain largely unexplored because their relation to relevant contexts or life-history stages could not be studied with individual-level resolution. Using on-bird microphone transmitters, we recorded the vocalisations of individual zebra finches (Taeniopygia guttata) behaving freely in social groups, while females and males previously unknown to each other passed through different stages of the breeding cycle. As birds formed pairs and shifted their reproductive status, their call repertoire composition changed. The recordings revealed that calls occurred non-randomly in fine-tuned vocal interactions and decreased within groups while pair-specific patterns emerged. Call-type combinations of vocal interactions changed within pairs and were associated with successful egg-laying, highlighting a potential fitness relevance of calling dynamics in communication systems.
Correlation values from vocal interaction matrices
Calling interactions in group-housed zebra finches: correlation values from vocal interaction matrices for call-type and bird combinations, calculated from PSTHs. Matrices were transposed to columns (focal bird) and rows (non-focal bird), and supplemented with information on: Trial; day; identity, sex and call type of focal and non-focal bird; whether interacting birds were pair members (Pairmembers(y/no)); whether vocal interactions were positive, non-significant or negative (Interaction(pos/0/neg); how call types were combined (combination.type); whether focal bird was in a pair that produced a clutch of eggs (focal.eggslaid); reproductive stage of the focal bird (nest.stage = summary, breeding.stage = more detailed).
Gill2015_allinteractions_summary.csv
Figure 2: Group reproductive stages change over time
This table contains the percentage of birds assigned to different reproductive stages (nest.stage = summary, breeding.stage = more detailed) for each day of the experiment, along with the absolute numbers (sum) and the number of birds measured (number_birds), for the calculation. Note that only the first 20 days are presented in the graph.
Gill2015_FIG2_source1_stages.csv
Figure 2 – figure supplement 1: Differences in steroid hormone concentrations at baseline levels and the three nest stages
For each trial and bird, we provide steroid hormone values (DHT = dihydrotestosterone, E2 = estradiol, P4 = progesterone, Testo = testosterone) in relation to sex, Timepoint of plasma collection (base = baseline, i.e. before females and males were joined in aviary; join1 = one day after males and females were joined, nestmat1 = one week later, one day after nest material was provided) and reproductive stages (baseline.nest.stage).
Gill2015_FIG2S1_source1_hormones.csv
Figure 4 and Figure 4 – Figure supplement 1: Female and male call-type usage at different nest stages and breeding stages
For each trial and bird, we provide the number of calls (nrCalls_extrapolated, extrapolated to 4 hours of recordings) and the proportion of calls (divided by the sum of all five call types) produced in different call types, with information on day, sex and reproductive stage (nest.stage = summary, breeding.stage = more detailed).
Gill2015_FIG4_source1_calltypes.csv
Figure 5 – figure supplement 1: Increasing specificity of within-pair vocal interactions
For each breeding stage, the overall mean number of calls per bird (within the five analysed call types, and extrapolated to four hours of recordings) with standard deviation, standard error and confidence intervals. We also show the specificity of pair calling interactions by providing within-pair (percentage.pair) and extra-pair (percentage.nonpartner) percentages of occurred positive (from respective possible) calling interactions.
Gill2015_FIG5S1_source1_callactivity_specificity_summary.csv
Figure 5B: Within-pair vocal interactions at different breeding stages
Percentages of positive within-pair interactions at different breeding stages, with respect to combination of call types (Call.Response.type), initiating bird’s sex (initiator.sex) and responding bird’s sex (responder.sex).
Gill2015_FIG5B_source1_summarypairinteractions.csv
Figure 6: Call-type combinations, nest stages and successful egg-laying
For each pair, we provide the mean number (pairmean) of positive, negative and non-significant (interaction.type: posit/neg/zero) call-type interactions at different reproductive stages (nest.stage) and in relation to successful egg-laying (eggslaid).
Gill2015_FIG6_sourcedata1_interactions_success.csv
