Data from: Social pairing in the absence of reproductive senescence in a socially monogamous songbird
Data files
Aug 01, 2025 version files 108.02 KB
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MOCH_ages_by_year_for_divorce_pub.csv
28.80 KB
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MOCH_breeding_ages_new_pairs_analysis_pub.csv
16.01 KB
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MOCH_breeding_ages_pairing_analysis_pub.csv
21.18 KB
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MOCH_pair_divorce_rate_dataframe_pub.csv
39.37 KB
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README.md
2.67 KB
Abstract
Reproductive senescence may affect mating decisions if older individuals produce fewer and lower-quality offspring, but the effect of reproductive senescence on mate choice decisions remains poorly understood. Mountain chickadees (Poecile gambeli) do not exhibit clear reproductive senescence within their natural lifespans and therefore offer a unique opportunity to test whether the absence or delay of reproductive senescence affects social mate choice for mates of certain ages. Given the lack of obvious reproductive senescence in this species, we predicted that older individuals would be preferred as social mates because pairing with an experienced mate is often associated with direct and indirect benefits. In apparent support of our predictions, we observed positive assortment for age within breeding pairs and older individuals were more likely to be paired with one another than expected by chance. However, assortative pairing also occurred within most younger age classes, and when we restricted our analyses to consider only new pairings, rates of assortative pairing within age classes were similar to those expected by chance. Thus, the observed pattern of age-related assortative mating in this system likely occurs due to longevity of some pair bonds rather than active assortment for age among individuals forming new pair bonds. Combined, our results suggest that choice of a social mate based on age may be constrained in socially monogamous mating systems when many individuals maintain long-term pair bonds.
Dataset DOI: 10.5061/dryad.9s4mw6mvf
Description of the data and file structure
R scripts and data files to run analyses for "Social pairing in the absence of reproductive senescence in a socially monogamous songbird".
Files and variables
File: MOCH_age_assortative_mating_pub.R
Description: R script to run correlation and permutation analyses to test for age assortative mating in Mountain Chickadees.
File: MOCH_divorce_rates_pub.R
Description: R script to calculate summary results of pairing across years and run divorce analyses.
File: MOCH_breeding_ages_pairing_analysis_pub.csv
Description: All breeding pairs and their ages by year for years 2017-2022.
Variables
- YEAR: year the pair bred together
- SEASON: season the pair bred together (seasons begin in September)
- ELEVATION: elevation (low or high), the pair bred and lived at
- NEST.ID: unique identifier for the pair's nest in that year
- M.ID: male identity
- F.ID: female identity
- F.age: female age in years
- M.age: male age in years
File: MOCH_breeding_ages_new_pairs_analysis_pub.csv
Description: Newly-formed breeding pairs and their ages by year (season).
Variables
- YEAR: year the pair bred together
- SEASON: season the pair bred together (seasons begin in September)
- ELEVATION: elevation (low or high), the pair bred and lived at
- NEST.ID: unique identifier for the pair's nest in that year
- M.ID: male identity
- F.ID: female identity
- F.age: female age in years
- M.age: male age in years
File: MOCH_pair_divorce_rate_dataframe_pub.csv
Description: All breeding pairs, their ages by year for years 2015-2022, and whether the male and female were alive in the next year.
Variables
- YEAR: year the pair bred together
- SEASON: season the pair bred together (seasons begin in September)
- ELEVATION: elevation (low or high), the pair bred and lived at
- NEST.ID: unique identifier for the pair's nest in that year
- M.ID: male identity
- F.ID: female identity
- P.ID: pair identity
- M.alive.later: was the male alive in the following year? (Alive or Dead)
- F.alive.later: was the female alive in the following year? (Alive or Dead)
File: MOCH_ages_by_year_for_divorce_pub.csv
Description: Mountain Chickadee ages in each year they were alive.
Variables
- BirdID: individual identity
- Season: season the bird was active in
- Age: age in that season
Code/software
Code was written and run in R (v4.1.1).