Dataset DOI: 10.5061/dryad.z8w9ghxsv

Description of the data and file structure

We developed the Burrow Scale Monitor to passively measure adult mass of Leach's storm-petrels as they entered and exited their nesting burrow. We used these data to detect food delivery by parents to a single chick in the nesting burrow and the proportion of arrival weight that was allocated to the chick to test the parental strategy behind food allocation to chick or self. Data were collected at the Bowdoin Scientific Station at Kent Island, NB, Canada from 8 July to 9 August 2024.

Files and variables

• BEHECO-2025-0162_Main_Paper 
  • This is the data file on which all of the analyses presented to test the hypothesis addressed in the paper are based. Missing values are designated by "NA" for importing into R.
  • The fields include:
    • Burrow: ID for each nesting burrow and used as a random effect in all analyses
    • Filename: original data file on which the weight calculations as described in Supplemental Materials were based. These are the original raw data files from the Burrow Scale Monitor's weights were derived. The filename format is includes the date the data were collected. These are not necessary for any analyses and are only here for reference. See "Raw Data Availability" below.
    • RFID: Unique ID from RFID chip for the adults in the current analysis, if known. Used as a random effect in some analyses.
    • Wt_Entry: entry weight of the adult into the burrow on a particular feeding event (g)
    • Wt_Exit: exit weight of the adult from the burrow on a particular feeding event (g)
    • Wt_Del: difference betwen Wt_Entry and Wt_Exit (g)
    • LoadSize: ABS(Wt_Del) - food delivery to chick (g)
    • PCT: LoadSize / Wt_Entry (proportion)
    • ChickAge: unit = days where 0 = first day chick found in burrow
    • DOY: Day of year

• BEHECO-2025-0162_Suppl
  • The data used in the Validation Procedure described in Supplemental Materials
  • The fields include:
    • File: original data file on which the weight calculations as described in Supplemental Materials were based. These are the original raw data files from the Burrow Scale Monitor's weights were derived. The filename format is includes the date the data were collected. These are not necessary for any analyses and are only here for reference. See "Raw Data Availability" below.
    • Run: the iteration for the bird tested
    • Weight_BSM: calculate weight of adult (g)
    • Scale: Actual weight of the adult (g)
    • Err_New: Scale - Weight_BSM (g)
    • Less43: flag for printing (0 or 1) that designates Weight_BSM that were recalculated using the Manual method as described in the Supplemental Materials.

Raw Data Availability

• The raw BSM data collected and raw data analysis are described in Supplemental Materials
• Raw data were collected at ~60z for 24 hours resulting in daily files for each burrow of > 70MB
• Raw data are available on request (mauckr@kenyon.edu)

Code/software

Statistical Software:

-- All analyses were conducted in R version 4.1.1 (R Core Team 2021). We used linear mixed effects modeling (‘lmer’) with the package ‘lme4’ version 1.1-27.1 (Bates et al. 2015) to estimate the relationships between variables in the field data.

-- All models involved normally distributed response variables. We used linear mixed models (LMM) fit by restricted maximum likelihood (REML) with the default ‘identity’ link. Within the LMMs, we used Satterthwaite's method in 'lmerModLmerTest' to calculate the t-value of the independent variables (lmerTest Package version 3.1-3; 2021).

Contact for information about the datasets

• Robert Mauck
• Kenyon College
• email: mauckr@kenyon.edu