Table 3.

Life span of three‐spined sticklebacks in relation to changes in their swimming endurance and in the duration of breeding ornamentation (blue eye colour). The full model included season of experiment (Winter or Spring), photoperiod treatment (ambient or delayed) and sex (male or female) as fixed effects, compensatory growth rate, age‐related changes in swimming endurance and in the duration of breeding ornamentation (partitioned into between‐group effects due to diet treatment, and within‐group effects due to remaining individual variation) as covariates, and tank as a random effect, plus 2‐way interactions. Non‐significant variables were dropped from the final model. Note that a positive estimate indicates a longer life span. The parentheses represent the reference coding of the categorical variable

Final model	Estimate ± SE	F	d.f.	P
Intercept	971·727 ± 14·236
Season (Winter)	67·443 ± 17·261	15·27	1, 24·72	0·001
Sex (Male)	−34·707 ± 17·336	4·01	1, 77·49	0·049
Within‐group effect of swimming endurance	569·979 ± 167·019	11·65	1, 77·28	0·001
Between‐group effect of breeding ornamentation	101·304 ± 24·049	17·74	1, 24·42	<0·001
Within‐group effect of breeding ornamentation	185·904 ± 38·039	23·89	1, 77·68	<0·001