DOI: 10.5061/dryad.9s4mw6mvf
title: Data from: Social pairing in the absence of reproductive senescence in a socially monogamous songbird

description: 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.
description: # Data from: Social pairing in the absence of reproductive senescence in a
 socially monogamous songbird Dataset DOI:
 [10.5061/dryad.9s4mw6mvf](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).