DOI: 10.5061/dryad.0k6djhb7h
title: Data and code for: Behavioral plasticity shapes participation in a mixed-species flocking community of birds

description: Behavioral plasticity can modulate the costs and benefits of sociality,
 and thus may play a prominent role in mediating competition and
 facilitation during social interactions in mixed-species groups. However,
 investigations of assembly patterns of mixed-species groups typically
 treat species’ behavioral attributes as static rather than dynamic
 features that can change in social contexts. We investigate four axes of
 behavioral plasticity that may modulate interaction within mixed-species
 groups: 1) species’ selective preference for joining certain groups, 2)
 species’ ability to flexibly change their behavior in response to
 groupmates’ behavior, and 3) shifts and/or 4) expansions of species’ niche
 occupancy when foraging with conspecifics versus when foraging with
 heterospecifics. We assess variation in these axes of behavioral
 plasticity in an Australian mixed-species avian community. All species had
 selective preferences for flocks of certain strata, and some flexibly
 matched their flockmates’ foraging strata. Three species exhibited
 patterns of niche shift, and one species showed niche expansion. These
 findings suggest that species converge in strata in mixed-species flocks
 despite the potential for increased competition and emphasize that species
 can plastically react to changes in their social environment in numerous
 ways. Acknowledgment of such plasticity is likely integral to
 understanding the nuances of heterospecific interactions.
description: We collected this data in an approximately 1000 ha study site
 within Brookfield Conservation Park in the lower Murray-Darling River
 Basin in South Australia. Flock observations occurred from August 2019 to
 December 2019, just before the beginning of the austral spring and bird
 breeding season, continuing through the end of the breeding season when
 most species had fledged young. Here we discuss only mixed-species
 foraging flocks, which we define as groups that contain two or more
 species and that actively move in a coordinated fashion while foraging.
 During the study period, we opportunistically observed foraging flocks
 throughout the day (beginning at dawn and ending before dusk) to determine
 species composition and foraging behavior of flock members. In total, we
 recorded 445 mixed-species foraging flocks, formed of a combination of 38
 species. Only flocks that were observed that were not categorized as
 "foraging flocks" were excluded from this data. Any other
 necessary data parsing is present in the code provided. We also include
 data on foraging observations of species in and out of flocks. For every
 species in each flock, we recorded the highest and lowest foraging strata
 in which its members were observed. We designated foraging strata by
 separating the environment into five distinct, ecologically relevant
 categories – ground, scrub, bush, low canopy, and high canopy
 (Supplementary Figure 1). The descriptions used to designate each category
 are as follows: 1) ‘ground’ was defined as open ground, free of
 vegetation, 2) ‘scrub’ consisted of plants taller than 5 cm but shorter
 than 20 cm—typically saltbush (<em>Atriplex </em>spp.), 3)
 ‘bush’ consisted of several species of bush that varied in height but the
 dominant species at our site were sheepbush (<em>Geijera
 linearifolia</em>), senna (<em>Senna artemisioides
 </em>ssp.), and bluebush (<em>Maireana </em>spp.), all
 of which are easily distinguishable from trees by their shape and
 structure, 4) ‘low canopy’ consisted of the lower half of branches and
 leaves on an individual tree (primarily <em>Eucalyptus
 </em>spp. and <em>Myoporum platycarpum</em>) (5) and
 ‘high canopy’ consisted of the upper half of branches and leaves on an
 individual tree. To explore how joining mixed-species
 flocks influences the foraging niches of focal species, we
 opportunistically recorded foraging behavior both in and out of flocks for
 a select set of focal species. For each individual of a species observed,
 we recorded a singular attempt to capture prey, successful or not, during
 that given foraging bout. For each foraging event, we recorded whether the
 individual was participating in a mixed-species or a conspecific flock,
 the stratum in which the foraging event took place, and the location of
 the event via GPS point. The strata designations used for these
 observations are the same as described in flocking observations above.
 Included in the data here are only those species for which 15 or more
 foraging observations were observed.
description: # Data and code for: Behavioral plasticity shapes participation in a
 mixed-species flocking community of birds
 [https://doi.org/10.5061/dryad.0k6djhb7h](https://doi.org/10.5061/dryad.0k6djhb7h) We investigate four axes of behavioral plasticity that may modulate interaction within mixed-species groups: 1) species’ selective preference for joining certain groups, 2) species’ ability to flexibly change their behavior in response to groupmates’ behavior, and 3) shifts and/or 4) expansions of species’ niche occupancy when foraging with conspecifics versus when foraging with heterospecifics. We assess variation in these axes of behavioral plasticity in an Australian mixed-species avian community. Here are the two data sets and the associated code to reproduce the results found in the above manuscript. ## Description of the data and file structure Contains 4 files, here are listed the file names and the contents: 1. **Dryad_FlexibilitySelectivity_Dryad_Version_20230902.Rmd** -This file is the code for analyses carried out in manuscript and the necessary data filtering for each step of the analysis. Code was written in R version 4.1.0, and code is saved as a notebook file. 2. **AustraliaFlockData2019Dryad.csv** -This file contains the observations for foraging flocks recorded at Brookfield Conservation Park in austral spring 2019. As noted in the paper, this file contains specifically foraging flocks and excludes aggregations or mobbing flocks that were observed. Some of these flocks, specifically those that do not have foraging height information are excluded for final analyses; the code for that filtering is included in the R code above. Packages required for analysis are listed at the top of the code. -Each row within the data file represents a unique species observed within each flock. -Column 1 is "FlockID", which is a unique identifier for each flock (each flock is represented by multiple rows, the number of rows is equal to the number of species observed in the flock) -Column 2 is "Day" which is the day of the month of the observation -Column 3 is "Month" which is the Month (August, September, October, or December) of the observation -Column 4 is the "Year" of the observation which is 2019 for all observations -Column 5 is "Time", which is the time of day of the flock observation. NA indicates a lack of data for that observation. -Column 6 is "Flock Type" (which will appear as "Flock.Type" once imported into R), which is foraging for all observations within this dataset -Column 7 is "Species", which is the species observation for each given flock. The species are listed as four letter codes. A list of the codes and the corresponding common and species names can be found in the file "Species code information.xlsx". There are four additional options for species, "unknown", "unknown2", "BabblerSp", and "woodswallow_sp". All four are considered "unidentified species" in our calculations for flock contributions (Supplementary Table 1), but are listed here as 4 different options so that they were not flagged as duplicates in analyses that they were retained in to calculate flock average foraging strata. -Column 8 is "Number" which is the number of individuals of the given species within the flock -Column 9 is "Height Low" (which will appear as "Height.Low" once imported into R), which is the low foraging strata of the given species within the flock. Strata levels are as follows: G = ground, S = scrub, B = bush, LC = low canopy, HC = high canopy. NA indicates a lack of data for that observation. -Column 10 is "Height High" (which will appear as "Height.High" once imported into R), which is the high foraging strata of the given species withi the flock. Strata levels are as follows: G = ground, S = scrub, B = bush, LC = low canopy, HC = high canopy. NA indicates a lack of data for that observation. 4. **Foraging_observations__2019_Dryad.csv** -This file contains the foraging strata observations for indiviuals of various species observed in and out of mixedd-species foraging flocks. This data is used in the analyses of niche shift and expansion. This file only contains data from those nine species for which we had 15 or more foraging observations for both foraging events within mixed-species flocks, and those in conspecific flocks only. -Each row within the data represents a different observation of an individual performing a prey capture event. -Column 1 is "observer", an identifier that indicates who made the observation. -Column 2 is the "observation" of a given observer that the row represents. Not all possible numbers are listed as species which had insufficient foraging observations for analysis were excluded from this file. -Column 3 is "day", the day of the month of observation -Column 4 is "month", the month of the observation (here listed as numerical months) -Column 5 is "year", which is 2019 for all observations -Column 6 is "species" which is the four-letter code used as shorthand to denote species ID. A list of the codes and the corresponding common and species names can be found in the file "Species code information.xlsx". -Column 7 is "conspecifics", which is the number of conspecific individuals that were observed with the given bird within a flock (mixed-species or conspecific) -Column 8 is "stratum", which is the foraging stratum. Strata levels are as follows: G = ground, S = scrub, B = bush, LC = low canopy, HC = high canopy. -Column 9 is "flock_type", which is the flock type of the observation. There are two levels, "conspecific" = individual was either alone or with only members of its own species, or "heterospecific" = individual was with other species. 6. **Species code information.xlsx** -This file contains the four-letter code used in the files "AustraliaFlockData2019Dryad.csv" and "Foraging_observations_2019_Dryad.csv" to identify species. There are three columns, column 1 is the four letter species code, column 2 is the common name of that species, and column 3 is the scientific name. -This file is not used in any analysis, but is provided to ensure users are able to interpret the shorthand used in the code and in the datafiles. ## Code/Software Code was created for use in the R programing language and is presented in R notebook form.