Data from: The scope and adaptive value of modulating aggression across breeding stages: Case study in a competitive female songbird
Data files
May 10, 2024 version files 25.14 KB
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data_(1).csv
18.16 KB
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README.md
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Abstract
In seasonally breeding animals, costs and benefits of territorial aggression should vary over time; however, little work thus far has directly examined the scope and adaptive value of individual-level plasticity in aggression across breeding stages. We explore these issues using the tree swallow (Tachycineta bicolor), a bird species in which females compete for limited nesting sites before producing a single brood. We measured the aggressiveness of nearly 100 females within three different stages: (1) shortly after territory-establishment, (2) during early incubation, and (3) while caring for young chicks. We used k-means clustering to categorize females into four distinct plasticity ‘types’ based on the timing, direction, and magnitude of their changes in aggression between stages. We then tested whether plasticity type and stage-specific aggression vary with key performance metrics. Two of the four plasticity types became less aggressive across consecutive breeding stages, consistent with population-level patterns, though these plasticity types largely did not differ from one another in survival or reproductive success. A third type was characterized by high levels of among-stage plasticity; these females, had significantly lower body mass while parenting, tended to hatch fewer eggs, and had the lowest observed overwinter survival rates. A final type exhibited limited plasticity, with moderate to low levels of aggression in all stages; this low plasticity - low aggression phenotype was not associated with any negative effects to performance. These results reveal substantial among-individual variation in behavioral plasticity, which may reflect diverse solutions to trade-offs between current reproduction and future survival.
README: Data from: The scope and adaptive value of modulating aggression across breeding stages: Case study in a competitive female songbird
Paper: Scope and adaptive value of modulating aggression over breeding stages in a competitive female bird
Authors: Elizabeth M George, Abigail M Weber, Kimberly A Rosvall
Description:
This README file describes the data accompanying the above publication.
Each line of data refers to data collected from one female tree swallow during one particular year. Below are descriptions of the contents of each column:
- Year= calendar year. 2018 corresponds to Y1 in text, 2020 corresponds to Y2
- F_ID= female ID (unique 9-digit federal band #)
- Age_class = y1 = one year old (brown plumage) females, y2+ are females 2y old or older (blue-green plumage)
- Age= age in years
- How_aged= whether female’s age is exact (‘known’) or an estimated minimum, based on their plumage when originally banded (see next 3 columns)
- year_banded= year when female was first banded. Used with ‘Age_class_whenbanded’ to estimate age
- Age_class_whenbanded = whether females were nestlings (y0), one-year old brown plumaged (y1) or 2y or older (blue-green plumage; y2+) when first banded. Used for estimating age
- banded_in_prioryear= yes or no (Y/N), whether a female had previously been captured/banded at one of our study sites. Indicates whether a female was new to our study population at the time of the aggression assays
- TE_STI_score, Inc_STI_score, C_STI_score: result of 5 minute aggression assay (STI), defined as # of 5 sec time bins that contained any aggressive behavior (range= 0-60)
- TE = aggression measured during Territory Establishment (TerrEst) stage, Inc= during incubation, C= during chick-rearing
- F_mass: female body mass, measured in grams
- ‘NA’s indicates that we did not measure body mass during Inc or C for that female.
- F_mass_stage: breeding stage in which body mass was measured (either Inc for incubation or C for chicks) breeding stage (Inc or C). All Y2 measurements occurred during C, and almost all Y1 measurements occurred during Inc.
- F_return_nextyr: whether a female was captured at our study sites in the following year’s breeding season (2019 for Y1, 2021 for Y2). Used as a proxy for overwinter survival. Y= ‘yes, female returned’, N= ‘no, female was not seen again’
- laydate_first= the date of a female's first clutch initiation, used in analyses of 'first egg day' as a response variable
- laydate_brood= the date of a female's clutch initiation for the nest whose chicks' mass and survival were analyzed. this differed from laydate_first only for the select cases in which a female's first clutch failed and she successfully relaid and raised chicks
- relaid_nest = whether or not the reproductive data from a female (n_c_hatched, avg_D12_c_mass, etc.) came from a female’s second attempt at a nest, because her first nest failed for some reason. Y= yes, was a relaid nest, N= not a relaid nest. Used to filter data prior to analyses of reproductive performance
- n_e_laid= number of eggs laid by a female (specific to one reproductive effort, not counting relaid nests). Represents clutch size except in the cases when clutch reduction occurred (next column)
- clutch_reduct= ‘clutch reduction amount’. how many eggs were artificially removed from a nest after laying but before hatching
- n_e_couldhatch= ‘number of eggs that could hatch’. The difference between n_e_laid and clutch_reduct. Used to measure hatching success
- hatchdate= calendar date on which the majority of a brood hatched
- n_c_euth_d6= ‘the number of chicks euthanized on day 6 post-hatch’. A count of the number of chicks terminally collected for another study- occurred on day 6 post-hatch
- n_c_d12- ‘number of chicks alive in nest on day 12 post-hatch’
- ‘NA’ indicates that the number of chicks alive in the nest at that time could not be evaluated
- avg_D12_c_mass= brood-average chick mass (in grams) on day 12 post-hatch
- ‘NA’ indicates that 0 chicks were alive in the nest on day 12 (i.e., the nest ‘failed’ due to predation, abandonment, etc.), and thus body mass could not be measured
- n_c_euthd12= ‘number of chicks euthanized on day 12 post-hatch’. A count of the number of chicks terminally collected for another study- occurred after day 12 mass measurements
- n_c_alive_pd12= ‘number of chicks alive post-day 12’, calculated as the difference between n_c_d12 and n_c_euthd12
- ‘NA’ indicates that 0 chicks were alive in the nest on day 12 (i.e., the nest ‘failed’ due to predation, abandonment, etc.), so this measure is irrelevant
- brood_reduction= ‘total artificial brood reduction’, sum of n_c_euth_d6 and n_c_euthd12
- c_recruit= ‘chick recruitment’. Binary variable: were any fledged chicks from this brood captured found in the breeding population the following year? (Y= yes/N=no)
- ‘NA’ indicates that 0 chicks were alive in the nest on day 12 (i.e., the nest ‘failed’ due to predation, abandonment, etc.), so fledgling recruitment could not be measured
- Year_ID= concatenation of Year and Female ID, giving unique ID per female per breeding season
- TE_Inc_scorediff= ‘TE, Inc STI score difference’. Inc STI score minus TE STI score
- Inc_C_scorediff= = ‘Inc, C STI score difference’. C STI score minus Inc STI score
- fmass_ebr= ‘female mass-relevant experimental brood reduction’. A binary variable indicating whether a clutch or brood reduction occurred prior to a female’s body mass measurement (Y=yes, N=no)
- fsurv_ebr= ‘female survival- relevant experimental brood reduction’. A binary variable indicating whether a clutch or brood reduction occurred at any stage, which could have affected a female’s survival to the next year (Y=yes, N=no)
- hatch_ebr = ‘hatch-relevant experimental brood reduction’. A binary variable indicating whether a clutch reduction occurred prior to hatching, which could have affected hatcing success (Y=yes, N=no)
- d12m_ebr= ‘day 12 chick mass-relevant experimental brood reduction’ A binary variable indicating whether a clutch or brood reduction occurred prior to chick mass measurements on day 12 post-hatching (Y=yes, N=no)
- csurv_ebr= ‘chick survival/recruitment-relevant experimental brood reduction’. A binary variable indicating whether a clutch or brood reduction occurred at any stage, which could influence whether chicks were recruited into the study population in the following year (Y=yes, N=no)
- F_return_nextyr_bi = ‘female return next year binary’, converts the F_return_nextyr into 0s and 1s, for statistical analyses (N=0, Y=1).
R script for data analyes and figures is also provided, to be run in sequential order using this data set.
Methods
Collection and processing of the data described in detail in the manuscript "The scope and adaptive value of modulating aggression across breeding stages: case study in a competitive female songbird".
Usage notes
All analyses were conducted in R.