Table 2. Model predictors.

Parameters for the 217 clutches used in the Bayesian model relating clutch fertility to the characteristics of the clutch mother and clutch father (the male and female which produced the clutch). See Fig. S2 for distributions of the numeric variables.

Component	Variable	Type	Values (frequency)
Response	Clutch fertility	Binary	0 (80) / 1 (137)
Fixed	Mother hand-reared	Logical	true (64 clutches; 26 females) / false (153 clutches; 34 females)
	Father hand-reared	Logical	true (43 clutches; 12 males)/false (174 clutches; 38 males)
	Mother age (years)	Continuous	range = 4.8–48.5, mean = 20.9, median = 17.8
	Father age (years)	Continuous	range = 4.8–43.4, mean = 22.7, median = 20.8
	Mother copulation behaviour	Categorical	1 copulation (104)/1 male, >1 copulation (50)/Different males (63)
	Mother previous copulations	Integer	range = 0–17, mean = 4.4, median = 4
	Father previous copulations	Integer	range = 0–33, mean = 6.5, median = 4
Random	Mother/father kinship	Continuous	range = 0 –0.265, mean = 0.021, med = 0.0074
	Mother	Categorical	60 individuals, 1 –9 repeats, mean = 3.6, median = 3
	Father	Categorical	50 individuals, 1 –16 repeats, mean = 4.3, median = 4
Year	Categorical	range = 1990 –2019, 16 levels