DOI: 10.5061/dryad.h70rxwdrn
title: Social association of monk parakeets in relation to proximity and relatedness

description: Monk parakeets are social parrots that live in loose colonies, often
 building communal nests and breeding cooperatively. Relatives are
 clustered within nests and within colonies. Data was collected to test the
 hypothesis that social associations of monk parakeets when away from their
 nests (foraging, collecting nest material, etc) are driven by either the
 spatial proximity of their nests and/or by their relatedness. The dataset
 includes information on the identities of all birds that could potentially
 associate with a focal bird when away from their respective nests, an
 index of their association strength (calculated using the simple ratio
 index), the distance between their respective nests, the dyadic
 relatedness of the birds estimated using microsatellite genotypes, the
 number of times the two birds were seen together, and the total number of
 times the focal bird was observed. Data are separated into different files
 according to the  year of data collection (2018 or 2019) to avoid
 pseudoreplication. Additional files exclude data from each year collected
 at a feeding station; these data files relate to a conservative anlaysis
 in case the supply of supplementary food affected social associations. An
 additional file contains data only for birds whose nests were in the same
 tree; this file was for an analysis of the effect of relatedness on social
 association while controlling for nest proximity. Finally, a file is also
 included that contains the 2018 as described above, but with dyads defined
 by sex (male-male, female-male or female-male). Each data file relates to
 a specific analysis in the paper. The conclusion is that monk parakeets do
 have specific social associations with conspecifics, and that these are
 infleuenced by nest proximity but not by genetic relatedness.
description: The field study was conducted in the city of Barcelona, Spain
 (41.39°N 2.17°E). The main study site encompassed Ciutadella Park (c. 30
 ha) and smaller parks and streets with mature trees in the surrounding
 area up to approximately 2 km away. Birds were individually marked with
 aluminium leg rings and a unique, light-weight medal attached to neck
 collars, which are visible through binoculars from up to 30-40 m. Blood
 samples were also taken. In 2018 and 2019, we recorded
 groups of individually-marked monk parakeets away from the nest throughout
 the breeding season (March-September) in two contexts. First, groups of
 monk parakeets were recorded opportunistically when encountered in the
 field site. We used the ‘gambit of the group’, which assumes that all
 individuals in a spatially and temporally clustered group are associated
 with one another. Individuals were recorded as being in the same group if
 they were within c. 5 m of each other and any individuals that joined the
 group within approximately 2 minutes of the observer encountering the
 group were included as group members. GPS coordinates, date and time of
 each group were recorded. Secondly, groups were recorded during
 observations made at a feeding station containing peanuts and sunflower
 seeds, situated on the roof of the Museu de Ciències Naturals within
 Ciutadella Park. These observations were conducted for approximately three
 hours a week throughout the breeding season following the same
 protocols.  Blood samples (maximum 100 µl) were taken
 from adults and nestlings for genetic sex-typing and to assess genetic
 relatedness between individuals. Alleles were scored blind to bird
 identity and sex and individuals were typed at 21 polymorphic
 microsatellite loci: Mmon01, Mmon02, Mmon03, Mmon04, Mmon07, Mmon09,
 Mmon10, Mmon11, Mmon13, Mmon14, Mmon15, Mmon16 (Dawson Pell <em>et
 al</em>., 2020), MmGT060, MmGT046, MmGT105, MmGT030, MmGT071,
 MmGT057 (Russello <em>et al</em>., 2007), TG03-002 and
 TG05-046 (Dawson <em>et al</em>., 2010), and CAM-20 (Dawson
 <em>et al</em>., 2013). Individuals were sex-typed using the
 sexing marker Z002B (Dawson, 2007).We calculated pairwise genetic
 relatedness between individuals using Queller and Goodnight’s (1989)
 coefficient of relatedness (r<sub>QG</sub>) in SPAGeDi version
 1.5 (Hardy & Vekemans, 2002). We used the genotypes of all 142
 unique individuals included in our social association dataset to generate
 allele frequencies. The nesting tree location of marked
 birds was determined in two ways. First, we conducted detailed behavioural
 observations at 10 mature pine trees in Ciutadella Park throughout the
 breeding season in 2018 and 2019. A total of 113 marked birds were located
 in these focal trees in 2018 and 103 in 2019. Birds were never observed to
 enter a nest chamber they were not using for breeding or roosting during
 our period of observation, so we are confident that birds assigned as nest
 occupants were residents in that nest and nesting tree. Second, we
 conducted surveys in the rest of Ciutadella Park and in likely nesting
 areas up to 6 km from the park in 2018 and 2019. Once marked birds were
 assigned to a nest, we recorded the nest’s GPS coordinates; all birds in
 the same nesting tree were assigned the same GPS coordinates with a
 distance of 0 m between their nests. GPS coordinates were converted to
 Cartesian coordinates (UTM) for calculations of inter-nest distance in
 SPAGeDi version 1.5 (Hardy & Vekemans, 2002). We calculated
 inter-nest distances separately for 2018 and 2019.
 Using flock co-membership, we calculated association indices
 using the simple ratio index (SRI; Cairns & Schwager, 1986),
 which varies between 0 and 1, with 1 indicating that individuals are
 always observed together and 0 indicating two individuals have never been
 observed associating. The simple ratio index is calculated using the
 following equation:
 SRI<em><sub>AB</sub></em> = <em>x /
 </em>(<em>x </em>+ <em>y<sub>AB
 </sub></em>+<em> y<sub>A</sub> </em>+
 <em>y<sub>B</sub></em>) in
 which the SRI between the individuals <em>A</em> and
 <em>B </em>is defined as the number of observations in which
 the two co-occurred (<em>x</em>), divided by the number of
 observations in which they both occurred together or individually, with
 <em>y<sub>AB </sub></em>representing the occasions
 the individuals were observed simultaneously but apart and
 <em>y<sub>A </sub></em>indicating occasions that
 individual <em>A</em> was observed without individual
 <em>B</em> and<em> y<sub>B
 </sub></em>indicating the reverse. We excluded birds observed
 on less than five occasions and also birds observed in their fledging year
 because they were still fed by their parents and were therefore likely to
 be associated with them away from the nest. Only those dyads with data for
 inter-nest distance and relatedness are included. 
 References Cairns SJ, Schwager SJ. 1986. A
 comparison of association indices. <em>Animal Behaviour</em>
 35: 1454–1469. Dawson DA. 2007. Genomic analysis of
 passerine birds using conserved microsatellite loci. PhD Thesis,
 University of Sheffield, Sheffield, UK Dawson DA, Ball
 AD, Spurgin LG, Martín-Gálvez D, Stewart IRK, Horsburgh GJ, Potter J,
 Molina-Morales M, Bicknell AW, Preston SAJ, Ekblom R, Slate J, Burke T.
 2013. High-utility conserved avian microsatellite markers enable parentage
 and population studies across a wide range of species. <em>BMC
 Genomics</em> 14: 176.
 https://doi.org/10.1186/1471-2164-14-176 Dawson DA,
 Horsburgh GJ, Küpper C, Stewart IRK, Ball AD, Durrant KL, Hansson B, Bacon
 I, Bird S, Klein Á, Krupa AP, Lee J-W, Martín-Gálves D, Simeoni M, Smith
 G, Spurgin LG, Burke T. 2010. New methods to identify conserved
 microsatellite loci and develop primer sets of high cross-species utility
 - as demonstrated for birds. <em>Molecular Ecology
 Resources</em> 10: 475–494.
 https://doi.org/10.1111/j.1755-0998.2009.02775.x Dawson
 Pell FSE, Hatchwell BJ, Ortega-Segalerva A, Dawson DA, Horsburgh GJ, Senar
 JC. 2020. Microsatellite characterisation and sex-typing in two invasive
 parakeet species, the monk parakeet <em>Myiopsitta
 monachus</em> and ring-necked parakeet <em>Psittacula
 krameri</em>. <em>Molecular Biology Reports</em> 47:
 1543–1550. https://doi.org/10.1007/s11033-019-05215-6 Hardy OJ, Vekemans X. 2002. SPAGeDi: a versatile computer program to analyse spatial genetic structure at the individual or population levels. <em>Molecular Ecology Notes</em> <strong>2</strong>: 618–620. https://doi.org/10.1046/j.1471-8278 Queller DC, Goodnight KF. 1989. Estimating relatedness using genetic markers. <em>Evolution</em> 43: 258. https://doi.org/10.2307/2409206
description: # Social association of monk parakeets in relation to proximity and
 relatedness ## Description
 of the data and file structure The basic structure of each file is the
 same for most data files. The following description is for '2018 full
 database', '2019 full database', '2018 database
 excluding trap data', '2019 database excluding trap data'
 and '2018 same tree only'. C1 ID1 - Focal bird identity (note
 that all bird IDs may be just a numeral or a letter followed by a
 numeral). C2 ID2 - Identity of other marked birds in the population with
 whom focal bird could associate with. C3 Association - Simple Ratio Index
 (SRI) as a metric of social association (range 0 - 1). SRI is calculated
 from x (C10 - the number of occasions when the focal bird *A* was seen
 with potential associate *B*) and y (C11 - the number of occasions the
 focal bird *A* was observed without the potential associate *B*) using the
 equation SRI*AB* = x / (x + y*A* + y*B*). C4 Distance - The distance in m
 between the nests of the focal bird and its potential associate. C5
 Relatedness - The coefficient of relatedness between the focal bird and
 its potential relatedness. C6 SortCol - The identity of the specific dyad
 of focal bird and potential associate, coded with a combination of
 individual marks. C7 Sort - The identity of the specific dyad of focal
 bird and potential associate, coded uniquely and numerically 1, 2, 3, etc.
 C8 Associated - Binary classification of whether focal bird and potential
 associate were observed together, coded numerically as together (1) or not
 (0). C9 Associated2 - Binary classification of whether focal bird and
 potential associate were observed together, coded textually as together
 (TRUE) or not (FALSE). C10 x - The number of occasions when the focal bird
 was seen in a group with that potential associate. C11 y - The number of
 occasions when the focal bird was seen in a group without that potential
 associate. The '2018 full database' and '2019 full
 database' are separated by year because some birds were present in
 both years and others were not. Therefore, to avoid pseudoreplication we
 analysed each year separately. In both cases, data were collected in two
 contexts: (i) by observation of birds foraging together in parks and other
 green spaces in Barcelona, and (ii) by observations at a baited trap on
 the roof of the Museu de Ciences Naturals in Ciutadella Park, Barcelona.
 The '2018 database excluding trap data' and '2019 database
 excluding trap data' included only data collected in context (i). We
 excluded data collected in context (ii) in analyses using these datasets
 because the supplementary food (peanuts and sunflower seeds) provided at
 the trap may have resulted in unnatural social associations. The
 '2018 same tree only' dataset included only those birds whose
 nests were situated in the same tree. This dataset was analysed to
 determine whether there was any effect of dyadic relatedness on social
 association when controlling for nest proximity (0 for all dyads).
 Finally, the '2018 including trap split by sex' dataset includes
 all the association, nest proximity and relatedness data collected in 2018
 in both contexts, using the same data columns (C1-C11) as listed above,
 but with the addition of columns specifying the sexes of the birds in the
 dyad. Here, we wanted to know whether male-male, female-female and
 male-female dyads were driven by the predictors as in the full dataset.
 Therefore, we specified additional columns, as follows: C12 sex.x - Sex of
 the focal bird. C13 sex.y - Sex of the potential associate. C14 same -
 Binary classification of whether the focal bird and potentially associated
 bird were the same sex (Y) or not (N). C15 Two-sexes - Specifying whether
 the two birds were 'FEMALES', 'MALES' or
 'OPPOSITE' sex.