Descriptive statistics
In our dataset, the mean RTL was 1.29 (s.d. = 0.64, range = 0.14 – 6.61). 1,225 individuals were sampled between the age of 0–7, with a mean of 1.7 samples per bird (range = 1 – 9). Further summaries are in Tables 1 and 2. At the time of analysis, 11 individuals were still alive. Excluding these individuals, the mean lifespan was 1.7 years (s.d. = 1.7, range = 0 – 9, N = 1,214; 572 females and 637 males), and the mean LRS was 1.5 (s.d. = 2.7, range = 0 – 16). ARS of all birds in the dataset had a mean of 0.6 (s.d. = 1.1, range = 0 – 8, N = 1,225; 579 mothers and 641 fathers).