Fig. 1.

Survival plot of C. secundus queens. Shown is the age-dependent survival probability (filled squares) of queens with 95 % confidence intervals (x) estimated with Kaplan Meier survival analyses. The median longevity of queens in the laboratory after successful colony establishment was estimated with Kaplan Meier survival analysis to be 12 years (mean longevity: 11.1 years). The maximum lifespan was 13 years. After an age of around 11 years, life expectancy declines rapidly; out of eight queens with a potential age ≥ 12 years, all had died, except one 13-year old queen. Note, the x-axis starts at an age of two because by default the queens had to survival for the first year to be included in our study