Dataset DOI: 10.5061/dryad.fqz612k5j

Description of the data and file structure

The data contains three demographic transition matrices stored as comma-separated values (.csv):

1. The file "matrix_ALL.csv" contains the age-specific fecundities in the first row and the year-to-year transition probability from age i to age i+1 (i.e., age-specific survivorships) in the subdiagonal for Heermann's gulls females in a non-anomalous year.
2. The file "matrix_BA.csv" contains the age-specific fecundities in the first row and the year-to-year transition probability from age i to age i+1 (i.e., age-specific survivorships) in the subdiagonal for Heermann's gulls females following the bold reproductive strategy in an anomalously warm year.
3. The file "matrix_CA.csv" contains the age-specific fecundities in the first row and the year-to-year transition probability from age i to age i+1 (i.e., age-specific survivorships) in the subdiagonal for Heermann's gulls females following the conservative reproductive strategy in an anomalously warm year.

Code/software

We used R Studio for all analyses. Three files containing computer script coded in the R Statistical Language are included:

• The file "Pop_matrix_script_eigensolutions.R" contains the script used to calculate the eigensolutions of the three demographic matrices.
• The file "Pop_matrix_script_randomizations.R" contains the script used for the numerical calculation of confidence intervals on the three demographic matrices.
• The file "Pop_matrix_script_recurr_intervals.R" contains the script used to calculate the effect of different intervals of recurrence of warm-phase anomalies on the demography of both bold and conservative Heermann's gulls.