DOI: 10.5061/dryad.5qfttdzfx
title: Data from: Observational and experimental evidence that rapid mass loss is consistent with the flight efficiency hypothesis and not caused by reproductive effort in three passerine species

description: Breeding birds often lose mass abruptly around the time that their eggs
 hatch, but the reasons why and the demographic significance of mass loss
 are contentious. Energy expenditure during offspring provisioning
 is one long-standing explanation that fits with life history theory
 (energetic cost hypothesis). Mass loss may also reflect time constraints
 that limit foraging and self-maintenance while warming (i.e., brooding)
 young (time constraint hypothesis). Alternatively, mass loss may be an
 adaptive strategy to provide benefits through decreased energetic flight
 costs while foraging and provisioning young (flight efficiency
 hypothesis). To test these hypotheses, we measured mass loss
 across the nesting cycle for three passerine species using an automated
 weighing system and quantified reproductive effort by filming nests. We
 also experimentally manipulated reproductive effort using a nest heating
 experiment to test effects on mass loss. Counter to the energetic
 cost hypothesis, female mass loss did not match changing parental
 provisioning effort across the reproductive cycle; mass loss in all three
 species started about five days before eggs hatched and finished well
 before nestling provisioning effort was greatest. The nest heating
 experiment reduced female and male provisioning rates but did not
 influence mass loss in either sex, also rejecting the energetic cost
 hypothesis. Counter to the time constraint hypothesis, more time spent
 brooding was associated with less mass loss. Path analysis
 supported the flight efficiency hypothesis for females, where mass loss
 was not related to energetic costs or time constraints and was positively
 associated with fledging more and heavier young, as well as a greater
 proportion of young. Mass loss also did not influence the chance of
 double-brooding or survival to the next breeding season. Males lost mass
 steadily over the nesting cycle, but our results did not strongly support
 one hypothesis. Ultimately, results supported mass loss providing
 adaptive benefits for females, while rejecting reproductive cost
 hypotheses often expected under life history theory.
description: # Observational and experimental evidence that rapid mass loss is
 consistent with the flight efficiency hypothesis and not caused by
 reproductive effort in three passerine species
 [https://doi.org/10.5061/dryad.5qfttdzfx](https://doi.org/10.5061/dryad.5qfttdzfx) ## **R Scripts (listed in order of the workflow)** **1_Mass_loss_estimate_models.R** - This is the code for producing estimates of the change in mass across the nesting cycle for females and males at each nest.  **2_Reproductive_effort_estimate_models.R** - This is the code for producing estimates of the different reproductive parameters across the nesting cycle for each nest.  **3_Nestling_growth_estimate_models.R** - This is the code for producing the estimates of nestling mass and wing chord on day 15 for each nest.  **4_Dataset_building.R** - This is the code for combining the predicted estimates of mass and reproductive effort into one dataset and calculating all the parameters that we need for the analysis.  **5_Initial_analysis.R** - This is the code for the series of linear and generalized linear models for the initial analysis. **6_heating_experiment.R** - This is the code for the series of linear and models to evaluate the effects of the nest heating experiment. **7_Path_analysis.R** - This is the code for the path analysies. **8_Mass_loss_models_for_figures.R** - This is the code for producing estimates of the change in mass across the nesting cycle for females and males at each nest for the figures. It differs from “1_Mass_loss_estimate_models.R” by producing estimates for each species (or first brood vs. second brood, etc.), rather than producing estimates for each nest. **9_Reproductive_effort_models_for_figures.R** - This is the code for producing estimates of the different reproductive parameters across the nesting cycle for each nest for the figures. It differs from “2_Reproductive_effort_estimate_models.R” by producing estimates for each species (or first brood vs. second brood, etc.), rather than producing estimates for each nest. **10_Figures.R** - This is the code for producing the figures. Some of the figures are produced within the other files, but that is noted in this file.  ## **Data files** In the data files, all the missing data were entered as NA(s). **Raw_mass_data.csv** - This is the raw mass data collected by the automated scale setup. Each line represents one mass that was measured. -nest_ID_obs: A unique number for each mass collected at that nest. -nest_ID: A unique identification code for each nest. -NID: A unique number for each nest for each year (so numbers overlap between different years). -box: The number of the nest box. -spp: Species (BCCH = Black-capped Chickadee, HOWR = House Wren, MOCH = Mountain Chickadee) -date: The data that that mass was measured on. -year: Year. -julian day: The julian date. -stage: LAY = egg laying; INC = incubation period; NSTL = nestling period; FLDG = Fledge day. -eggs: The number of eggs in the nest on that day. -nestlings: The number of nestlings in the nest on that day. -day: Day of that stage, so 1 in the INC stage is the first day of incubation, 1 in the NSTL stage is the first day of the nestling period. -days to hatch: Number of days to hatch. E.g., -10 = 10 days before hatch, 10 = 10 days after hatch. -brood: 1 = first brood, 2 = second brood. -hatched: yes = the eggs hatched at that nest. no = the eggs didn’t hatch at the nest because they were infertile (which was the case for 4 MOCH nests). -experiment: Whether the nest was used as a control nest in the heating experiment (control), a heated nest in the experiment (heat), or not used in the experiment (no). -male_present: Whether that nest had a male attending it (a couple were widowed females; yes / no). -failed_early: Whether the nest failed before making it to day 15 of the nestling period or not (yes / no). -file name: The name of the video file that that mass came from. Generally, the GoPro videos were split into files that were 17.5 minutes long. -video_clip_start: The time of day that that specific video file started at. -video_time: The time (in the video, not the time of day) that that mass was measured at.  -time: The time of day that that mass was measured at (so, video_clip_start + video_time). -sex: F = female, M = male. -combo: The bandcombo of that bird. The first letter is the upper band on the left leg, the second letter is the lower band on the left leg, the third letter is the upper band on the right leg, the fourth letter is the lower band on the right leg. UB = that bird was unbanned. A-only = That bird had only an aluminum band, no color bands.  A = federal aluminum band, G = green, B = blue, Y = yellow, K = black, R = red, H = hot pink, W = white, O = orange, V = violet (purple). -bird_ID: A unique combo for each bird, composed of the species, sex, and band combo.  -before_weight: The mass (g) displayed on the scale at the second the bird landed on it. -bird_on_weight: The stabilized mass (g) displayed on the scale while the bird was perched on it. -bird_weight: The before_weight subtracted from the bird_on_weight (bird_on_weight - before_weight). -carrying_something: no = the bird was not carrying food or nest material while perched on the scale; yes = the bird was carrying food or nest material while perched on the scale; unk = unknown. -what_carrying: description of what the bird was carrying. nothing = the bird wasn’t carrying anything. -carrying_weight: The estimated mass of what the bird was carrying. -adj_mass: bird_weight minus carrying_weight. **Raw_reproductive_effort_data.csv** - This is the raw reproductive effort data collected by filming nests with camcorders. Each line represents one video that was filmed on one day. -SPP: Species (BCCH = Black-capped Chickadee, HOWR = House Wren, MOCH = Mountain Chickadee) -Year: Year. -Nest_ID: A unique identification code for each nest. -NID: A unique number for each nest for each year (so numbers overlap between different years). -Box: The number of the nest box. -Date: The data that that mass was measured on. -Julian_Date: The julian date. -Stage: INC = incubation period; NSTL = nestling period. -Stage_Day: Day of that stage, so 1 in the INC stage is the first day of incubation, 1 in the NSTL stage is the first day of the nestling period. -days_to_hatch: Number of days to hatch. E.g., -10 = 10 days before hatch, 10 = 10 days after hatch. -Video: A unique number for each video.  -BroodSize: The number of nestlings in the nest for each video. -F_ID: Unique identify code for the female at that nest. -M_ID: Unique identify code for the male at that nest. -Brood: 1 = first brood, 2 = second brood. -Hatched: Whether the eggs of that nest hatched or not (yes / no) -Experiment: Whether the nest was used as a control nest in the heating experiment (control), a heated nest in the experiment (heat), or not used in the experiment (no). -Male_Present: Whether that nest had a male attending it (a couple were widowed females; yes / no). -Failed_Early: Whether the nest failed before making it to day 15 of the nestling period or not (yes / no). -Start_Time1: The time of day that that video started at. -Duration: The duration of that video (in hours). -Julian_Incubatoin: The julian date of the first day of incubation (aka the day the last egg was laid). -F_percent_on: Female incubation or brooding attentiveness (%) for that video. -M_feed_rate: Male hourly mate feeding (for incubation videos) or nestling provisioning rate (for nestling period videos) for that video. -F_feed_rate: Female hourly nestling provisioning rate for that video. **Raw_nestling_measurement_data.csv** - The raw dataset of nestling measurements used in the “3_Nestling_growth_estimate_models.R” file. Each line represents one nestling measured on one day. -SPP: Species (BCCH = Black-capped Chickadee, HOWR = House Wren, MOCH = Mountain Chickadee) -Year: Year. -Box: The number of the nest box. -Observer: The initials of the person who took the measurements. -NID: A unique number for each nest for each year (so numbers overlap between different years). -Nest_ID: A unique identification code for each nest. -Date: The data that the measurements were taken on. -Time: The time of day that the measurements were taken. NA = no time available. -Color: Both tarsi of each nestling were marked with colored markers to identify them each day, so this is the two colors. K = black, B = blue, G = green, R = red, NA = no color band. -Mass: The mass (g) of that nestling. NA = measurement not taken, usually because that nestling was dead. -Tarsus: The length of the tarsus (mm) of that nestling. NA = measurement not taken, usually because that nestling was dead. -Wing_Chord: The length of the wing chord (mm) of that nestling. NA = measurement not taken, usually because that nestling was dead. -Federal_Band: The band number of that nestling, once they were banded. NA = the nestling wasn’t banded yet. -Day: The day of the nestling period that the nestling was measured on. -Hatch_Date: The date that the eggs of that nest hatched. **Predicted_mass_data.csv** - This dataset is produced in the “1_Mass_loss_estimate_models.R” file. It is the predicted mass of each male and female at each nest for each day of the nesting cycle. -days.to.hatch: Number of days to hatch. E.g., -10 = 10 days before hatch, 10 = 10 days after hatch. -nest_ID: A unique identification code for each nest. -time_num: The median time of day that the masses of that species were measured (in seconds from midnight). Predicted values of mass are for that time of day. -adj_mass: The predicted mass (g) of that individual female or male at each nest. -se: Standard error of “adj_mass:. -lower_ci: The lower 95% confidence interval of adj_mass. -upper_ci: The upper 95% confidence interval of adj_mass. -sex: F = female, M = male. -NID: A unique number for each nest for each year (so numbers overlap between different years). -box: The number of the nest box. -spp: Species (BCCH = Black-capped Chickadee, HOWR = House Wren, MOCH = Mountain Chickadee) -year: Year. -brood: 1 = first brood, 2 = second brood. -hatched: yes = the eggs hatched at that nest. no = the eggs didn’t hatch at the nest because they were infertile (which was the case for 4 MOCH nests). -male_present: Whether that nest had a male attending it (a couple were widowed females; yes / no). -failed_early: Whether the nest failed before making it to day 15 of the nestling period or not (yes / no). -experiment: Whether the nest was used as a control nest in the heating experiment (control), a heated nest in the experiment (heat), or not used in the experiment (no). -min_day: The first day either sex had their mass measured for that nest (so negative days for the incubation period, positive for the nestling period) -min_day_F: The first day that the female had their mass measured for that nest (so negative days for the incubation period, positive for the nestling period) -min_day_M: The first day that the male had their mass measured for that nest (so negative days for the incubation period, positive for the nestling period) -max_day: The last day either sex had their mass measured for that nest (so negative days for the incubation period, positive for the nestling period) -max_day_F: The last day that the female had their mass measured for that nest (so negative days for the incubation period, positive for the nestling period) -max_day_M: The last day that the male had their mass measured for that nest (so negative days for the incubation period, positive for the nestling period) -data_range: Whether that day is within or outside the range of days that that female’s or male’s mass was measured at that nest.  **Predicted_reproductive_effort_data.csv** - This dataset is produced in the “2_Reproductive_effort_estimate_models.R” file. It is the predicted value of each of the reproductive effort parameters for each nest for each day of the nesting cycle. -days_to_hatch: Number of days to hatch. E.g., -10 = 10 days before hatch, 10 = 10 days after hatch. -Nest_ID: A unique identification code for each nest. -The median video duration (in hours) for that species. -F_percent_on_pred: The predicted value of female nest attentiveness (%, incubation or brooding) for that day. -F_percent_on_pred_se: The standard error of F_percent_on_pred. -F_percent_on_pred_low_CI: The lower 95% confidence interval of F_percent_on_pred. -F_percent_on_pred_upper_CI: The upper 95% confidence interval of F_percent_on_pred. -SPP: Species (BCCH = Black-capped Chickadee, HOWR = House Wren, MOCH = Mountain Chickadee) -Year: Year. -NID: A unique number for each nest for each year (so numbers overlap between different years). -Box: The number of the nest box. -F_ID: Unique identify code for the female at that nest. -M_ID: Unique identify code for the male at that nest. -Brood: 1 = first brood, 2 = second brood. -Hatched: yes = the eggs hatched at that nest. no = the eggs didn’t hatch at the nest because they were infertile (which was the case for 4 MOCH nests). -Experiment: Whether the nest was used as a control nest in the heating experiment (control), a heated nest in the experiment (heat), or not used in the experiment (no). -Male_Present: Whether that nest had a male attending it (a couple were widowed females; yes / no). -Failed_Early: Whether the nest failed before making it to day 15 of the nestling period or not (yes / no). -Julian_Incubation: The julian date that incubation started for that nest (aka the day the last egg was laid). -min_vid_day: The first (minimum) day that that nest was filmed to quantify reproductive effort. E.g., -10 means 10 days to hatch. -max_vid_day: The last (max) day that the nest was filmed to quantify reproductive effort. E.g., 10 means 10 days after hatch. -vid_data_range: Whether that day is within or outside the range of days that the nest was filmed to quantify reproductive effort. -F_feed_rate_pred: The predicted value of hourly female nestling provisioning rate for that day. -F_feed_rate_pred_se: The standard error of F_feed_rate_pred. -F_feed_rate_pred_low_CI: The lower 95% confidence interval of F_feed_rate_pred. -F_feed_rate_pred_upper_CI: The upper 95% confidence interval of F_feed_rate_pred. -M_feed_rate_pred: The predicted value of hourly male nestling provisioning rate for that day. -M_feed_rate_pred_se: The standard error of M_feed_rate_pred. -M_feed_rate_pred_low_CI: The lower 95% confidence interval of M_feed_rate_pred. -M_feed_rate_pred_upper_CI: The upper 95% confidence interval of M_feed_rate_pred. **Predicted_nestling_growth_data.csv** - This dataset is produced in the “3_Nestling_growth_estimate_models.R” file. It is the predicted value of nestling mass and wing chord for days 9 and 15 for each nest. -SPP: Species (BCCH = Black-capped Chickadee, HOWR = House Wren, MOCH = Mountain Chickadee) -Year: Year. -Box: The number of the nest box. -NID: A unique number for each nest for each year (so numbers overlap between different years). -Nest_ID: A unique identification code for each nest. -Mass_pred_D9: The predicted value of nestling mass (g) in that nest on day 9 of the nestling period. -Mass_pred_D15: The predicted value of nestling mass (g) in that nest on day 15 of the nestling period. -WC_pred_D9: The predicted value of nestling wing chord (mm) in that nest on day 9 of the nestling period. -WC_pred_D15: The predicted value of nestling wing chord (mm) in that nest on day 15 of the nestling period. -num_nstl_D9: The number of nestlings in the nest on day 9. -num_nstl_D15: The number of nestlings in the nest on day 15. -Brood_mass_D9: Brood mass in grams (Mass_pred_D9 * num_nstl_D9) on day 9 of the nestling period. -Brood_mass_D15: Brood mass in grams (Mass_pred_D15 * num_nstl_D15) on day 15 of the nestling period. **Nest_master.csv** - This is a file which contains basic info about each nest (e.g., brood size, whether or not it was successful), which is combined with the mass loss and reproductive effort data in the “4_Dataset_building.R” file to create the dataset used in the analyses.  -Year: Year. -NID: A unique number for each nest for each year (so numbers overlap between different years). -Nest_ID: A unique identification code for each nest. -Species: Species (BCCH = Black-capped Chickadee, HOWR = House Wren, MOCH = Mountain Chickadee) -Box: The number of the nest box. -Incubation_Fate: 1 = Eggs hatched (successful). 2 = failed, unknown reason. 2.3 = Depredated (failed), 2.4 = Failed due to adult disappearing, likely due to mortality. 4.1 = Nest occupied but insufficient info to determine fate. -Nestling_Fate: 1 = Nestlings fledged (successful). 2.3 = Depredated (failed), 2.4 = Failed due to adult disappearing, likely due to mortality, 2.6 = Failed due to weather. 2.8 = Failed due to nestling mortality (used when nestlings die even when adults are still alive), 4.2 = Nest active, but monitoring discontinued because of the end of the field season. -Nest_Fate: 1 = Nestlings fledged (successful). 2.3 = Depredated (failed), 2.4 = Failed due to adult disappearing, likely due to mortality, 2.6 = Failed due to weather. 2.8 = Failed due to nestling mortality (used when nestlings die even when adults are still alive), 4.2 = Nest active, but monitoring discontinued because of the end of the field season. -TotalDays: The number of days that the nest was active. -Clutch_Size: The number of eggs laid. -Hatched: The number of eggs that hatched. -Brood_Size: The average number of nestlings over the nestling period. -Fledged: The number of nestlings that fledged from the nest. -Brood: 1 = first brood, 2 = second brood. -Incubation_Date: The date that incubation started (aka, the date that the last egg was laid) -F_ID: Unique identify code for the female at that nest. -M_ID: Unique identify code for the male at that nest. -F_2ndBrooded: yes = female initiated a second brood. no = female didn’t initiate a second brood. -M_2ndBrooded: yes = male participated in a second brood. no = male didn’t participate in a second brood. -F_surv: yes = female survived to breed in the next year. no = female didn’t survive to breed in the next year. -M_surv: yes = male survived to breed in the next year. no = male didn’t survive to breed in the next year. **Final_chickadee_dataset.csv** - This is the full dataset used in the analyses (“5_Initial_analysis.R”, “6_heating_experiment.R”, and “7_Path_analysis.R” files). This dataset is produced in the “4_Dataset_building.R” file. -SPP: Species (BCCH = Black-capped Chickadee, HOWR = House Wren, MOCH = Mountain Chickadee) -Nest_ID: A unique identification code for each nest. -Box: The number of the nest box. -Year: Year. -F_ID: Unique identify code for the female at that nest. -M_ID: Unique identify code for the male at that nest. -Brood: Whether that nest is a first (1) or second (2) brood nest. -Hatched.x: Whether the eggs of that nest hatched or not (yes / no) -Male_Present: Whether that nest had a male attending it (a couple were widowed females; yes / no). -Failed_Early: Whether the nest failed before making it to day 15 of the nestling period or not (yes / no). -Experiment: Whether the nest was used as a control nest in the heating experiment (control), a heated nest in the experiment (heat), or not used in the experiment (no). -max_F_mass: The maximum mass (g) that the female reached. -min_F_mass: The minimum mass (g) the the female reached. -F_mass_DN5: Female mass (g) on day -5 (5 days prior to hatch). -F_mass_hatch_day: Female mass (g) on hatch day (day 0). -F_mass_lost_DN5D0: Female mass lost (g) from day -5 (5 days to hatch) and hatch day (day 0). -F_mass_lost_DN5D10: Female mass lost (g) from day -5 (5 days to hatch) to 10 days after hatch (day 10). -F_mass_lost_D0D10: Female mass lost (g) from hatch day (day 0) to 10 days after hatch (day 10). -max_M_mass: The maximum mass (g) that the male reached. -min_M_mass: The minimum mass (g) the the male reached. -M_mass_DN5: Male mass (g) on day -5 (5 days prior to hatch). -M_mass_hatch_day: Male mass (g) on hatch day (day 0). -M_mass_lost_DN5D10: Male mass lost (g) from day -5 (5 days to hatch) to 10 days after hatch (day 10). -M_mass_lost_D0D15: Male mass lost (g) from hatch day (day 0) to 15 days after hatch (day 15). -Min_day_Fmass_measured: The first day that female mass was measured (so negative days for the incubation period, positive for the nestling period) -Max_day_Fmass_measured: The last day that female mass was measured (so negative days for the incubation period, positive for the nestling period) -Min_day_Mmass_measured: The first day that male mass was measured (so negative days for the incubation period, positive for the nestling period) -Max_day_Mmass_measured: The last day that male mass was measured (so negative days for the incubation period, positive for the nestling period) -Fon_avg_DN5D0: Average female nest attentiveness (%) from 5 days prior to hatch (day -5) to hatch day (day 0) -Fon_avg_INC: Average female nest attentiveness (%) during the incubation period. -Fon_avg_D0_10: Average female brooding attentiveness (%) from days 0 - 10 of the nestling period. -Ffeed_avg_D0_10: Average hourly female nestling provisioning rate from days 0 - 10 of the nestling period. -Ffeed_avg_D0_15: Average hourly female nestling provisioning rate from days 0 - 15 of the nestling period. -Mfeed_avg_INC_DN5D0: Average hourly male mate feeding rate from 5 days to hatch to hatch day. -Mfeed_avg_D0_10: Average hourly male nestling provisioning rate from days 0 - 10 of the nestling period. -Mfeed_avg_D0_15: Average hourly male nestling provisioning rate from days 0 - 15 of the nestling period. -min_vid_day: The first (minimum) day that that nest was filmed to quantify reproductive effort. E.g., -10 means 10 days to hatch. -max_vid_day: The last (max) day that the nest was filmed to quantify reproductive effort. E.g., 10 means 10 days after hatch. -Clutch_Size: Number of eggs laid. -Incubation_Fate: 1 = eggs hatched (successful). 2 = eggs didn’t hatch (or predated before then; failed). -Nestling_Fate: 1 = Nestlings fledged (successful). 2.3 = Depredated (failed), 2.4 = Failed due to adult disappearing, likely due to mortality, 2.8 = Failed due to nestling mortality (used when nestlings die even when adults are still alive), 4.2 = Nest active, but monitoring discontinued because of the end of the field season. -Nest_Fate: 1 = Nestlings fledged (successful). 2.3 = Depredated (failed), 2.4 = Failed due to adult disappearing, likely due to mortality, 2.8 = Failed due to nestling mortality (used when nestlings die even when adults are still alive), 4.2 = Nest active, but monitoring discontinued because of the end of the field season. -Eggs_hatched: The number of eggs that hatched. -Brood_Size: The average number of nestlings throughout the nestling period. -Fledged: The number nestlings that fledged from the nest. -Incubation_Date: The date that incubation started (aka, the date that the last egg was laid) -F_2ndBrooded: yes = female initiated a second brood. no = female didn’t initiate a second brood. -M_2ndBrooded: yes = male participated in a second brood. no = male didn’t participate in a second brood. -F_surv: yes = female survived to breed in the next year. no = female didn’t survive to breed in the next year. -M_surv: yes = male survived to breed in the next year. no = male didn’t survive to breed in the next year. -Mass_pred_D15: The predicted average mass (g) of nestlings in that nest on day 15 (15 days after hatch). -WC_pred_D15: The predicted average wing chord (mm) of nestlings in that nest on day 15 (15 days after hatch). -num_nstl_D15: The number of nestlings in the nest on day 15 (15 days after hatch). -Brood_mass_D15: Mass_pred_D15 * num_nstl_D15. -INC_fate_simple: 1 = eggs hatched (successful). 0 = eggs didn’t hatch (or predated before then; failed). -NSTL_fate_simple: 1 = nestlings fledged (successful). 0 = nestlings didn’t fledge (failed). -Nest_fate_simple: 1 = nestlings fledged (successful). 0 = nestlings didn’t fledge (failed). -Inc_DateC: The date that incubation started (aka, the date that the last egg was laid). -Inc_JDate: The Julian date that incubation started (aka, the date that the last egg was laid). **Predicted_mass_data_for_figures.csv** - This dataset is produced in the “8_Mass_loss_models_for_figures.R” file. It is the data used to produce figures 2 and S14. -spp: Species (BCCH = Black-capped Chickadee, HOWR = House Wren, MOCH = Mountain Chickadee) -sex: F = female, M = male.  -brood: 1 = first brood, 2 = second brood. -experiment: Whether the data is from control unheated nests (control), heated experimental nests (heat), or nests not used in the experiment (no). -failed_early: Whether the data is from nests that failed before making it to day 15 of the nestling period or not (yes / no). -male_present: Whether the data is from nests that had a male attending it (a couple had widowed females) or not (yes / no). -hatched: Whether the data is from nests whose eggs hatched or not (yes / no). -days.to.hatch: Number of days to hatch. E.g., -10 = 10 days before hatch, 10 = 10 days after hatch. -time_num: The median time of day that the masses of that species were measured (in seconds from midnight). Predicted values of mass are for that time of day. -adj_mass: The predicted mass (g) of that species for that and sex for that time of day. -se: Standard error of “adj_mass:. -lower_ci: The lower 95% confidence interval of adj_mass. -upper_ci: The upper 95% confidence interval of adj_mass. **Predicted_reproductive_effort_data_for_figures.csv** - This dataset is produced in the “9_Reproductive_effort_models_for_figures.R” file. It is the data used to produce figures 2 and S14. -SPP: Species (BCCH = Black-capped Chickadee, HOWR = House Wren, MOCH = Mountain Chickadee) -Brood: 1 = first brood, 2 = second brood. -Experiment: Whether the nest was used as a control nest in the heating experiment (control), a heated nest in the experiment (heat), or not used in the experiment (no). -Failed_Early: Whether the nest failed before making it to day 15 of the nestling period or not (yes / no). -Male_Present: Whether that nest had a male attending it (a couple were widowed females; yes / no). -Hatched: yes = the eggs hatched at that nest. no = the eggs didn’t hatch at the nest because they were infertile (which was the case for 4 MOCH nests). -days_to_hatch: Number of days to hatch. E.g., -10 = 10 days before hatch, 10 = 10 days after hatch. -Duration: The mean duration (in hours) of the videos filmed to quantify reproductive effort for that species. -F_percent_on: The predicted value of female nest attentiveness (%, incubation or brooding) for that day. -Fon_se: The standard error of F_percent_on. -Fon_lower_CI: The lower 95% confidence interval of F_percent_on. -Fon_upper_CI: The upper 95% confidence interval of F_percent_on. -M_feed_rate: The predicted value of hourly male nestling provisioning rate for that day. -Mfeed_se: The standard error of M_feed_rate. -Mfeed_lower_CI: The lower 95% confidence interval of M_feed_rate. -Mfeed_upper_CI: The upper 95% confidence interval of M_feed_rate. -F_feed_rate: The predicted value of hourly female nestling provisioning rate for that day. -Ffeed_se: The standard error of F_feed_rate. -Ffeed_lower_CI: The lower 95% confidence interval of F_feed_rate. -Ffeed_upper_CI: The upper 95% confidence interval of F_feed_rate. **Full_chickadee_summarized_dataset.csv** - This is very similar to the “Final_chickadee_dataset.csv”, except instead of having one just line for each nest, there is 25 lines for each nest, to cover days -10 to 15. This file is used to create figure 3. This dataset is produced in the “4_Dataset_building.R” file. -SPP: Species (BCCH = Black-capped Chickadee, HOWR = House Wren, MOCH = Mountain Chickadee) -Nest_ID: A unique identification code for each nest. NID: A unique number for each nest for each year (so numbers overlap between different years) -Box: The number of the nest box. -Year: Year. -days_to_hatch: Number of days to hatch. E.g., -10 = 10 days before hatch, 10 = 10 days after hatch. -adj_mass_pred_F: The predicted mass (g) of the female at that nest at that day. -adj_mass_pred_se_F: The standard error of adj_mass_pred_F. -adj_mass_pred_lower_ci_F: The lower 95% confidence interval of adj_mass_pred_F. -adj_mass_pred_upper_ci_F: The upper 95% confidence interval of adj_mass_pred_F. -min_mass_day_F: The first day that the female’s mass was measured at that nest. -max_mass_day_F: The last day that the female’s mass was measured at that nest. -mass_data_range_F: Whether that day is within or outside the range of days that the female’s mass was measured at that nest.  -adj_mass_pred_M: The predicted mass (g) of the male at that nest at that day. -adj_mass_pred_se_M: The standard error of adj_mass_pred_M. -adj_mass_pred_lower_ci_M: The lower 95% confidence interval of adj_mass_pred_M. -adj_mass_pred_upper_ci_M: The upper 95% confidence interval of adj_mass_pred_M. -min_mass_day_M: The first day that the male’s mass was measured at that nest. -max_mass_day_M: The last day that the male’s mass was measured at that nest. -mass_data_range_M: Whether that day is within or outside the range of days that the male’s mass was measured at that nest.  -Duration: The mean duration (in hours) of the videos filmed to quantify reproductive effort for that species. -F_percent_on_pred: The predicted value of female nest attentiveness (%, incubation or brooding) for that day. -F_percent_on_pred_se: The standard error of F_percent_on_pred. -F_percent_on_pred_low_CI: The lower 95% confidence interval of F_percent_on_pred. -F_percent_on_pred_upper_CI: The upper 95% confidence interval of F_percent_on_pred. -F_feed_rate_pred: The predicted value of hourly female nestling provisioning rate for that day. -F_feed_rate_pred_se: The standard error of F_feed_rate_pred. -F_feed_rate_pred_low_CI: The lower 95% confidence interval of F_feed_rate_pred. -F_feed_rate_pred_upper_CI: The upper 95% confidence interval of F_feed_rate_pred. -M_feed_rate_pred: The predicted value of hourly male nestling provisioning rate for that day. -M_feed_rate_pred_se: The standard error of M_feed_rate_pred. -M_feed_rate_pred_low_CI: The lower 95% confidence interval of M_feed_rate_pred. -M_feed_rate_pred_upper_CI: The upper 95% confidence interval of M_feed_rate_pred. -min_vid_day: The first day that that nest was filmed to quantify reproductive effort. E.g. -10 = 10 days before hatch. -max_vid_day: The last day that that nest was filmed to quantify reproductive effort. E.g. 10 = 10 days after hatch. -vid_data_range: Whether that day is within or outside the range of days that the nest was filmed to quantify reproductive effort. -F_ID: Unique identify code for the female at that nest. -M_ID: Unique identify code for the male at that nest. -Julian_Incubation: The julian date that incubation started for that nest (aka the day the last egg was laid). -Brood: 1 = first brood, 2 = second brood. -Hatched: yes = the eggs hatched at that nest. no = the eggs didn’t hatch at the nest because they were infertile (which was the case for 4 MOCH nests). -Male_Present: Whether that nest had a male attending it (a couple were widowed females; yes / no). -Failed_Early: Whether the nest failed before making it to day 15 of the nestling period or not (yes / no). -Experiment: Whether the nest was used as a control nest in the heating experiment (control), a heated nest in the experiment (heat), or not used in the experiment (no). -Stage: INC = incubation period, NSTL = nestling period. -max_F_mass: The maximum predicted mass (g) the female of that nest reached. -max_M_mass: The maximum predicted mass (g) the male of that nest reached. -min_F_mass: The minimum predicted mass (g) the female of that nest reached. -min_M_mass: The minimum predicted mass (g) the male of that nest reached. -F_mass_hatch day: The predicted mass (g) of the female on hatch day. -M_mass_hatch day: The predicted mass (g) of the male on hatch day. -F_mass_DN5: The predicted mass (g) of the female on day -5 (5 days before hatch). -M_mass_DN5: The predicted mass (g) of the male on day -5 (5 days before hatch). -F_mass_D10: The predicted mass (g) of the female on day 10 (10 after hatch). -M_mass_D10: The predicted mass (g) of the male on day 10 (10 after hatch). -F_mass_D15: The predicted mass (g) of the female on day 15 (15 after hatch). -M_mass_D15: The predicted mass (g) of the male on day 15 (15 after hatch). -F_mass_lost_DN5D0: The mass (g) that the female lost between 5 days to hatch and hatch day. -F_mass_lost_DN5D10: The mass (g) that the female lost between 5 days to hatch and 10 days after hatch. -M_mass_lost_DN5D10: The mass (g) that the male lost between 5 days to hatch and 10 days after hatch. -F_mass_lost_D0D10: The mass (g) that the female lost between hatch day and 10 days after hatch. -M_mass_lost_D0D15: The mass (g) that the male lost between hatch day and 15 days after hatch. -F_daily_mass_change: The change in female mass (g) between this day and the next day (so the last day of each Nest_ID is NA) -M_daily_mass_change: The change in male mass (g) between this day and the next day (so the last day of each Nest_ID is NA) -Fon_avg_INC: Average female nest attentiveness (%) during the incubation period. -Fon_DN5: Predicted female nest attentiveness (%) on day -5 (5 days before hatch). -Fon_DN4: Predicted female nest attentiveness (%) on day -4 (4 days before hatch). -Fon_DN3: Predicted female nest attentiveness (%) on day -3 (3 days before hatch). -Fon_DN2: Predicted female nest attentiveness (%) on day -2 (2 days before hatch). -Fon_DN1: Predicted female nest attentiveness (%) on day -1 (1 day before hatch). -Fon_D0: Predicted female nest attentiveness (%) on day 0 (hatch day). -Fon_D1: Predicted female nest attentiveness (%) on day 1 (1 day after hatch). -Fon_D2: Predicted female nest attentiveness (%) on day 2 (2 days after hatch). -Fon_D3: Predicted female nest attentiveness (%) on day 3 (3 days after hatch). -Fon_D4: Predicted female nest attentiveness (%) on day 4 (4 days after hatch). -Fon_D5: Predicted female nest attentiveness (%) on day 5 (5 days after hatch). -Fon_D6: Predicted female nest attentiveness (%) on day 6 (6 days after hatch). -Fon_D7: Predicted female nest attentiveness (%) on day 7 (7 days after hatch). -Fon_D8: Predicted female nest attentiveness (%) on day 8 (8 days after hatch). -Fon_D9: Predicted female nest attentiveness (%) on day 9 (9 days after hatch). -Fon_D10: Predicted female nest attentiveness (%) on day 10 (10 days after hatch). -Fon_D11: Predicted female nest attentiveness (%) on day 11 (11 days after hatch). -Fon_D12: Predicted female nest attentiveness (%) on day 12 (12 days after hatch). -Fon_D13: Predicted female nest attentiveness (%) on day 13 (13 days after hatch). -Fon_D14: Predicted female nest attentiveness (%) on day 14 (14 days after hatch). -Fon_D15: Predicted female nest attentiveness (%) on day 15 (15 days after hatch). -Fon_avg_DN5D0: Average female nest attentiveness (%) from 5 days prior to hatch (day -5) to hatch day (day 0) -Fon_avg_D0_10: Average female brooding attentiveness (%) from days 0 - 10 of the nestling period. -F_daily_Fon_change: The change in female brooding attentiveness between this day and the next day (so the last day of each Nest_ID is be NA). So, F_percent_on_pred from the day before minus F_percent_on_pred on this day. -Ffeed_D0: Predicted hourly female nestling provisioning rate on day 0 (hatch day). -Ffeed_D1: Predicted hourly female nestling provisioning rate on day 1 (1 day after hatch). -Ffeed_D2: Predicted hourly female nestling provisioning rate on day 2 (2 days after hatch). -Ffeed_D3: Predicted hourly female nestling provisioning rate on day 3 (3 days after hatch). -Ffeed_D4: Predicted hourly female nestling provisioning rate on day 4 (4 days after hatch). -Ffeed_D5: Predicted hourly female nestling provisioning rate on day 5 (5 days after hatch). -Ffeed_D6: Predicted hourly female nestling provisioning rate on day 6 (6 days after hatch). -Ffeed_D7: Predicted hourly female nestling provisioning rate on day 7 (7 days after hatch). -Ffeed_D8: Predicted hourly female nestling provisioning rate on day 8 (8 days after hatch). -Ffeed_D9: Predicted hourly female nestling provisioning rate on day 9 (9 days after hatch). -Ffeed_D10: Predicted hourly female nestling provisioning rate on day 10 (10 days after hatch). -Ffeed_D11: Predicted hourly female nestling provisioning rate on day 11 (11 days after hatch). -Ffeed_D12: Predicted hourly female nestling provisioning rate on day 12 (12 days after hatch). -Ffeed_D13: Predicted hourly female nestling provisioning rate on day 13 (13 days after hatch). -Ffeed_D14: Predicted hourly female nestling provisioning rate on day 14 (14 days after hatch). -Ffeed_D15: Predicted hourly female nestling provisioning rate on day 15 (15 days after hatch). -Ffeed_avg_D0_10: Average hourly female nestling provisioning rate from days 0 - 10 of the nestling period. -Ffeed_avg_D0_15: Average hourly female nestling provisioning rate from days 0 - 15 of the nestling period.\ -F_daily_Ffeed_change: The change in hourly female provisioning rate between this day and the next day (so the last day of each Nest_ID is NA). So, F_feed_rate_pred from the day before minus F_feed_rate_pred on this day. -Mfeed_ND10: Predicted hourly male mate feeding rate on day -10 (10 days before hatch). -Mfeed_ND9: Predicted hourly male mate feeding rate on day -9 (9 days before hatch). -Mfeed_ND8: Predicted hourly male mate feeding rate on day -8 (8 days before hatch). -Mfeed_ND7: Predicted hourly male mate feeding rate on day -7 (7 days before hatch). -Mfeed_ND6: Predicted hourly male mate feeding rate on day -6 (6 days before hatch). -Mfeed_ND5: Predicted hourly male mate feeding rate on day -5 (5 days before hatch). -Mfeed_ND4: Predicted hourly male mate feeding rate on day -4 (4 days before hatch). -Mfeed_ND3: Predicted hourly male mate feeding rate on day -3 (3 days before hatch). -Mfeed_ND2: Predicted hourly male mate feeding rate on day -2 (2 days before hatch). -Mfeed_ND1: Predicted hourly male mate feeding rate on day -1 (1 days before hatch). -Mfeed_avg_INC_DN5D0: Average hourly male mate feeding rate from 5 days to hatch to hatch day. -Mfeed_D0: Predicted hourly male nestling provisioning rate on day 0 (hatch day). -Mfeed_D1: Predicted hourly male nestling provisioning rate on day 1 (1 day after hatch). -Mfeed_D2: Predicted hourly male nestling provisioning rate on day 2 (2 days after hatch). -Mfeed_D3: Predicted hourly male nestling provisioning rate on day 3 (3 days after hatch). -Mfeed_D4: Predicted hourly male nestling provisioning rate on day 4 (4 days after hatch). -Mfeed_D5: Predicted hourly male nestling provisioning rate on day 5 (5 days after hatch). -Mfeed_D6: Predicted hourly male nestling provisioning rate on day 6 (6 days after hatch). -Mfeed_D7: Predicted hourly male nestling provisioning rate on day 7 (7 days after hatch). -Mfeed_D8: Predicted hourly male nestling provisioning rate on day 8 (8 days after hatch). -Mfeed_D9: Predicted hourly male nestling provisioning rate on day 9 (9 days after hatch). -Mfeed_D10: Predicted hourly male nestling provisioning rate on day 10 (10 days after hatch). -Mfeed_D11: Predicted hourly male nestling provisioning rate on day 11 (11 days after hatch). -Mfeed_D12: Predicted hourly male nestling provisioning rate on day 12 (12 days after hatch). -Mfeed_D13: Predicted hourly male nestling provisioning rate on day 13 (13 days after hatch). -Mfeed_D14: Predicted hourly male nestling provisioning rate on day 14 (14 days after hatch). -Mfeed_D15: Predicted hourly male nestling provisioning rate on day 15 (15 days after hatch). -Mfeed_avg_D0_10: Average hourly male nestling provisioning rate from days 0 - 10 of the nestling period. -Mfeed_avg_D0_15: Average hourly male nestling provisioning rate from days 0 - 15 of the nestling period. -M_daily_Mfeed_change: The change in hourly male provisioning rate between this day and the next day (so the last day of each Nest_ID is NA). So, M_feed_rate_pred from the day before minus M_feed_rate_pred on this day. **Heat_test_12-13May21.csv** - This is the data file used to produce figure S2. It is the data of nest temperatures from three fake inactive nests used to test the effects of the nest box heating. The figure shows the temperatures of one unheated control nest and two heated experimental nests.  -time2: Date and time. Sometimes excel messes up the formatting of this column. If the seconds column is removed and all values are rounded to the nearest minute, the code to produce the figure will not work. -temp: Temperature (C) of the nest. -logger: Which data logger, referring to the three different nests.