Table 2. Results of a binomial GLMM (link = probit) testing whether herring gull chicks prefer marine or terrestrial foods.

	Estimate	Standard error	Degrees of freedom	Z value	P-value
Intercept	−1.15	0.37	1
Diet treatment group	−0.05	0.33	1	−0.15	0.88
Test day 10 (proxy for chick age and compared to day 5 in intercept)	−0.002	0.011	1	0.70	0.49
Test day 15 (proxy for chick age and compared to day 5 in intercept)	0.02	0.46	1	0.05	0.96
Test day 35 (proxy for chick age and compared to day 5 in intercept)	0.15	0.53	1	0.28	0.78

Note:

Random term: Chick ID variance within the model accounted for = 0, standard deviation = 0. This term had to be included to account for repeated measures of individuals over time.