DOI: 10.5061/dryad.2z34tmpj9
title: Code and data for: Familiarity breeds success: pairs that meet earlier experience increased breeding performance in a wild bird population

description: This is a Data package that contains three separate datasets and the
 analysis code for a manuscript 'Familiarity breeds success: pairs
 that meet earlier experience increased breeding performance in a wild bird
 population '. The first Dataset (pairs_data_2007_10) and the second
 dataset (pairs_data_2011_14) contain the data used to analyse the
 influence of meeting time of a pair of Great tits (i.e. month in the first
 dataset, week in the second dataset, when a pair was first detected in a
 flock together) on different components of breeding success of a pair. The
 third dataset (meeting_and_divorce) was used to analyse whether meeting
 time of a pair (in winter prior to the breeding season t) influence the
 probability of a pair to stay together or separate (divorce) to the
 following breeding season (t+1).
description: Study system The great tit is a small,
 short-lived (adult survival rates 25-65%), cavity-nesting passerine. Pairs
 are socially monogamous and breed on distinct territories, laying on
 average 8.5 eggs, and fledging on average 7 chicks. After the breeding
 season, birds form fission-fusion flocks and breeding pairs generally form
 between birds co-occurring together in the same winter flocks. Most of the
 birds recruit into the breeding population in their first year.
 The data come from a wild population of great tits in Wytham
 Woods, Oxford (51° 46’ N, 1° 19’ W) that breeds almost entirely
 exclusively in nest boxes, between April and July, and pairs usually
 (&gt;98%) have only one breeding attempt per season. Breeding data are
 collected using standard protocols to record parental identities and
 breeding parameters of a pair (date of first egg, maximal clutch size,
 number of hatched chicks, and number of fledged young). The data on winter
 flocks were collected between the winter beginning in 2007 until the end
 of the winter in 2014. Winter data collection
 set-up Data on winter flocks were collected using
 radio-frequency identification (RFID) technology: birds marked with
 passive integrated transporders (PIT-tags) were detected on feeders
 equipped with RFID-antennae. An estimated 82% of the primary population is
 marked with PIT-tags. The winter data collection protocol (spatial
 positions and opening times of feeders) changed half way through the
 study. In the first three winters (2007/08 to 2009/10) data were collected
 between August and March when 16 (out of 67 feeders) were always opened,
 and these were rotated every four days. In the second three winters
 (2011/12 to 2013/14) data were collected between early September and early
 March when all of the 65 feeders were opened during each weekend. The
 feeder-availability protocol minimised the possibility that flocks would
 get attracted to the constant food sources and we assume that data
 gathered at feeders represent snapshots of the social composition of
 different flocks at the time of recording. Further, feeders do not
 influence reproductive success. Meeting time and
 social structure We applied the GMMEvent (Gaussian
 mixture model for event streams) method to the spatio-temporal datastream
 collected from the loggers to determine the flocking events. This method
 is robust for inferring flocking events and preferable to other methods
 such as using arbitary time intervals. Further, the flocking events
 extracted using this method are known to be non-random in social
 composition, related to individuals social associations in other contexts
 and important to various social processes such as information spread and
 mating. We defined pair meeting time as the month (the first 3 winters) or
 the week (the last 3 winters) when the members of the future breeding pair
 were first identified in the same flock (i.e. gambit of the group
 approach). Time-frames for these were chosen based on the collection
 set-up in each set of winters. A typical individual in
 this dataset experiences approximately five flock mates. Thus, it is
 reasonable to assume that future breeding partners have indeed met in the
 foraging flock when first observed together. Further, we know that birds
 of new pairs tend to spend the prior winter in the same flocks together,
 and previous work on the same dataset has shown that calculating the time
 when a pair first met in this way is good approximation of the beginning
 of pair bonding and relates to future pairing behaviour. Thus, we can be
 confident that majority of pairs not only meet, but also begin bonding in
 the time period (month, weekend) in which they were first detected in the
 same flock. Nevertheless, we also carried out additional sensitivity
 analysis ensure that our investigations are robust to these assumptions
 (see Supplementary methods and Statistical analysis section).
 Social networks were constructed based on flocking events using
 Simple Ratio Index (SRI), that describes the affinity of two individuals
 to co-occur in the same flock, and can range from 0 (never observed
 together) to 1 (always observed together). SRI is calculated as the number
 of of the times (within a certain period: winter, month, weekend in our
 case) that two individuals were observed in the same flocking event
 together, divided by the sum of times when they were observed at all (in
 the same flock, in different flocks at the same time, and when only one of
 the individuals was observed). Dataset
 construction To be included in our primary analysis a
 pair had to meet several requirements. First, it had to be newly formed in
 the winter prior to the breeding season. This excludes pairs that were
 familiar as they have previously bred together. Second, both pair members
 were detected at winter feeders at least once. Third, both members were
 tagged either prior to the winter of interest (as nestlings or adults), or
 had been newly tagged in the current winter as immigrants at least two
 sampling periods before the pair meeting time. This eliminates pairs that
 had been associating but not detected as such purely because one or both
 members were not tagged at the time. Finally, we excluded six pairs (out
 of overall close to 400 pairs, i.e. &lt;2%), where both individuals
 were known to be tagged prior to the winter, but were detected for the
 first time in the late autumn/winter (i.e. after October) as already
 paired. These pairs likely formed outside of the main woods, and returned
 already paired. These requirements were met by 169 pairs in 2008-2010
 breeding seasons, and by 252 pairs of the 2012-2014 breeding seasons.
 Amongst these, members of 29, and 9 pairs, respectively, were never
 detected in the same flock. In all of these pairs at least one of the
 birds was either detected at feeders very rarely (in the lowest
 20<sup>th</sup> percentile of the distribution of the number
 of times each bird was detected in a given winter), or had a larger number
 of detections but in one month/weekend only. Thus, the final sample size
 for the analysis included 140 pairs breeding in 2008-2010, and 243 pairs
 breeding in 2012-2014 spring. Meeting time and future
 mating decisions To tested whether new pairs (first
 breeding together in spring <i>t</i>) that met earlier in
 winter (preceding<i> t</i>) had a higher probability of
 breeding together in breeding season <i>t</i>+1 compared to
 pairs that started to associate later. We used data on only those pairs
 where both members had survived to breed in
 <i>t</i>+1.
description: This data package
 contains 1)
 pair_data_2007_10 dataset (text file) 2) pair_data_2011_14 dataset
 (text file) 3)
 meeting_and_divorce dataset (text file) 4) Culina_et_al_ProcB_2020 (R
 file) - an R code to load the datam conduct the main and supplementary
 analysis, and to plot main and supplementary Figures   Variable names &
 meaning 1)
 <strong>Datasets</strong> pair_data_2007_10 and
 pair_data_2011_14   F_ID           Unique ID of a
 female of a pair M_ID         Unique ID of a male
 of a par clutchsz    Maximal number of
 eggs in a nest laydate      Date when a first
 egg was layed in the nest, standardized per year (based on all
 breeding             pairs) n_chicks Number of hatched
 young n_fledged            Number of
 fledged yound h_succ        Hatching success =
 number of hatched young/ number of eggs succ_failure        Whether a
 nest field or did not fail to hatch (binary variable) f_tagged              Date when a
 female was first tagged m_tagged            Date when a
 male was first tagged f_first_seen        Month (first
 three winters) or a weekend (last three winters) when a tagged female was
 first detected at feeders (i.e. female arrival time) m_first_seen      Month (first
 three winters) or a weekend (last three winters) when a tagged male was
 first detected at feeders (i.e. male arrival time) first_seen_together         Month
 (first three winters) or a weekend (last three winters) when a pair was
 first detected in the same winter foraging flock (i.e. meeting
 time) FvsM_arrival       Difference
 between females and males arrival time met_vs_arrival   Difference
 between meeting time and the arrival time of the pair member who arrived
 later year      
 a year of data collection. In the first set of winters this has been coded
 as e.g. 2007, which refers to winter 2007/08 and breeding season
 2008. pair_type             A variable
 coding for breeding experience of female and male (old or new
 breeder) Imm_F  
 Immigration status of a female (immigrants were born outside of the
 woods) imm_M
 Immigration status of a male (immigrants were born outside of the
 woods) SRI_partner_winter         
 Simple Ratio Index of a pair bond calculated for the whole
 winter SRI_F_winter      Average SRI of
 a female during the whole winter degree_F_winter             
 Number of all the associates female had during winter SRI_M_winter    Average SRI of a
 male during the whole winter degree_M_winter            Number
 of all the associates male had during winter 1met_degree_F               
 Number of all the associates female had in the month (first three winters)
 or in the weekend (last three winters) when a pair met 1met_degree_M              
 Number of all the associates male had in the month (first three winters)
 or in the weekend (last three winters) when a pair met   records_winter_F            
 Number of visits a female made to the feeders during winter (this variable
 exist only in the first three winters) months_seen_F/weekends_seen_F           Number of months or weekends a female was detected during winter records_winter_M           Number of visits a male made to the feeders during winter (this variable exist only in the first three winters) months_seen_M/ weekends_seen_M      Number of months or weekends a male was detected during winter SRI_partner_1met            SRI of a pair bond in the month/weekend when a pair met maxSRI_F_1met                The highest SRI of a female in a month/weekend a pair first met avSRI_F_1met                   The average SRI of a female in a month/weekend a pair first met maxSRI_M_1met              The highest SRI of a male in a month/weekend a pair first met avSRI_M_f1met The average SRI of a male in a month/weekend a pair first met avSRI_allbirds_1met        The average SRI of all the birds in a network (that later bred) in a month/weekend a pair first met sdavSRI_allbirds_1met    The standard deviation of the SRI of all the birds in a network (that later bred) in a month/weekend a pair first met 50q        The value of the 50th percentile of the distribution of the all SRI’s (for all birds that later bred) in the month/ weekend when a pair met 75q The value of the 75th percentile of the distribution of the all SRI’s (for all birds that later bred) in the month/ weekend when a pair met   2) <strong>Dataset:</strong> meeting_and_divorce F_ID           Unique ID of a female of a pair M_ID         Unique ID of a male of a par clutchsz    Maximal number of eggs in a nest laydate      Date when a first egg was layed in the nest, standardized per year (based on all breeding             pairs) year       a year of data collection. In the first set of winters this has been coded as e.g. 2007, which refers to winter 2007/08 for the meeting time, breeding season 2008 for breeding success, and pair status  (faithful or divorced) in 2009 breeding season. period   a period of data collection (2007 to 2010, or 2011 to 2014) age_f     Whether female is a new or old breeder age_m   Whether male is a new or old breeder status_t+1           Mating status of a pair (divorced or faithful) in the t+1 breeding season status_bin           Mating status as 1 (divorced) or 0 (faithful) first_seen_together         Month (first three winters) or a weekend (last three winters) when a pair was first detected in the same winter foraging flock (i.e. meeting time) f_first_seen        Month (first three winters) or a weekend (last three winters) when a tagged female was first detected at feeders (i.e. female arrival time) m_first_seen      Month (first three winters) or a weekend (last three winters) when a tagged male was first detected at feeders (i.e. male arrival time)