DOI: 10.5061/dryad.x95x69ps8
title: Data for: Social network data in wild great tits during ontogeny

description: Sociality impacts many biological processes and is tightly linked to an
 individual’s fitness. To maximize advantages of group living, many social
 animals exhibit preferences for associating with individuals that provide
 the most benefits, such as kin, familiar individuals or those of similar
 phenotype. Such social strategies are not necessarily stable over time but
 can vary with changing selection pressures. In particular, young
 individuals transitioning to independence should continuously adjust their
 social behavior in light of developmental changes. However, social
 strategies exhibited during adolescence in animals are understudied and
 the factors underlying social network formation during ontogeny remain
 elusive. Here, we tracked associations of wild great tits (Parus major)
 during transition to independence and across their first year of life.
 Both spatial and social factors were predictors of dyadic associations,
 with fledglings initially preferring to associate with siblings and peers
 over non-parent adults. We found no evidence for preferred associations
 among juveniles of similar age or fledge weight, but juveniles were
 marginally more likely to increase associations if their parents were also
 associated. Similarly, they showed a weak preference for associating with
 their parents’ adult associates. By autumn, juvenile birds exhibited
 social strategies similar to those of adults, establishing stable social
 ties that persisted into next spring. Overall, this research demonstrates
 dynamic changes in social networks during ontogeny in a species with fast
 life history and limited parental care, which likely reflect changes in
 selective pressures. It further highlights the importance of long-term
 social bonds based on familiarity in this species. 
description: The study took place in the woodland around the Max Planck
 Institute of Animal Behavior in Radolfzell, Germany (47.76811, 8.99652
 [WGS84]) as part of a long-term project on social behavior in wild great
 tits. Tits were caught in mist nets throughout the year and equipped with
 a metal leg ring issued by the Radolfzell Bird Observatory and a unique
 passive integrated transponder (PIT) tag (Eccel Technology, EM4102) for
 long-term identification, then sexed and aged based on plumage (Svensson
 1992). To study their breeding behavior we provided 207 nest boxes
 (Schwegler type 1B, 2M, 3SV) across the woodland. During the breeding
 season (early April until June 2020), nest boxes were monitored at least
 twice per week, recording nest stages, clutch sizes, start of incubation,
 and hatch and fledge dates of nestlings. Breeding pairs were identified
 four days after chick hatching with a built-in RFID antenna around the
 entrance hole of a faceplate logger (Naturecounters Ltd.) that recorded
 PIT tags of adult birds entering the nest box. Any untagged adult
 individuals were subsequently caught in the nest box and equipped with a
 metal leg ring and a PIT tag. On day 15 after hatching, nestlings were
 temporarily removed from their nest box for weighing and were equipped
 with a metal leg ring and a PIT tag before being returned to their nest.
 Note that sex of nestlings cannot be determined based on plumage (Svensson
 1992) – sex was therefore not included in any of the analyses. To
 determine the exact date of fledging, we returned to the nest daily from
 22 days after hatching onwards until all nestlings had fledged.
 To record foraging associations among PIT-tagged birds, we
 deployed six feeders across the woodland at a distance of approximately
 150-200 m from each other, each fitted with two RFID antennae to record
 visiting birds’ PIT tags. The feeders were installed simultaneously for
 one 48-hour period per week during active data collection, following
 protocol established in previous studies (Farine et al. 2012). We
 collected data all throughout the breeding season into summer to record
 associations of juveniles during transition to independence. Furthermore,
 to investigate social network dynamics throughout birds’ first year of
 life, we collected data during three consecutive weeks each the following
 autumn, winter and spring, with 48-hours of data collection in each
 week.
description: # The ontogeny of social networks in wild great tits (<i>Parus
 major</i>)
 [https://doi.org/10.5061/dryad.x95x69ps8](https://doi.org/10.5061/dryad.x95x69ps8) ## File structure This repository contains files of three types: **1) Code:** * **flock formation analysis.R**: contains all the code necessary to reproduce the analyses and create the figures **2) Data:** * **Mill.data.summer/autumn/winter/spring.txt**: These four files contain the raw visitation data at network feeders collected across the four seasons. Columns incude: * Date.Time: date and time in format *yymmddHHMMSS* * Antennae: "M" or "A" for main and auxiliary RFID antennae on each feeder * PIT: unique alphanumeric passive integrated transponder tag of each bird * location: Mill1-6 for designating where the feeder was placed within the study area (see Figure 1 in main MS) * week: experimental week within the season (1-14 for summer; 1-3 each for autumn, winter, spring) * **species_age.txt:** contains information on individuals' metal leg rings, PIT tags, species and age in 2020 (when the study was conducted). Columns include: * Ring: alphanumeric metal leg ring number * Species: GRETI for great tit * PIT: unique alphanumeric passive integrated transponder tag of each bird * Age_in_2020: whether the bird was 'adult' or 'juvenile' in 2020 * **fledgling_data.txt:** contains information on great tit chicks hatched and fledged within the study area. Columns include: * Box: Designation of nest box (see Figure 1 main MS) * Ring: alphanumeric metal leg ring number * Tag: unique alphanumeric passive integrated transponder tag of each bird * Who: breeding parents are designated as 'Female' or 'Male', while offspring are designated as 'Chick' * Clutch_size: Final number of eggs that were incubated * Chick.weight: The weight of the nestlings in g on day 15 after hatching * Fledged: if NA, the chicks died before fledging. The numbers indicate the fledge day in # of days counting from the 1st of April. * Fledge.order: The order within which they left the nest box within their sibling cohort * Location: Either 'castle' or 'Guettingen'. This study focused only on chicks from the 'Castle' location * Coordinates_long: Longitude of the location of the nest box (in WGS84) * Coordinates_lat: Latitude of the location of the nest box (in WGS84) * **gmm.summer/autum/winter/spring.RData:** contains the processed visitation data to feeders after running the *gmmevents* function from package *asnipe* that groups visitors to the feeders into distinct foraging flocks based on their arrival times. Each other season contains the full three weeks of data collection. These objects contain two relevant slots: * $metadata: each row refers to a group, with arrival and departure times * $gbi: group by individual matrix, where each row refers to a group, and columns to individuals. Individuals receive a 1 if present in the respective group, and a 0 if absent in the group. * **gmm.summer1-14.RData:** These 14 files contain the processed visitation data to feeders after running the *gmmevents* function from package *asnipe* that groups visitors to the feeders into distinct foraging flocks based on their arrival times. Due to computational reasons, they had to be constructed separately for each experimental week. Slots are equivalent to above. **3) Output:** * Output files from brms models (see main MS for designation of analysis numbers): * Analysis 1: **model.fl.formation.RDA** * Analysis 2: **model.fl.formation.phenotype.RDA** * Analysis 3: **model.fl.formation.inh.ad.RDA** and **model.fl.formation.inh.juv.RDA** * Analysis 4: no model output available (all results are visible in the supplied R code) * Analysis 5: **model.autumn.prev.RDA**, **model.winter.prev.RDA** and **model.spring.prev.RDA** ## Sharing information All codes and data are also available on github: [https://github.com/sonjawild/fledige_flock_formation](https://github.com/sonjawild/fledige_flock_formation)