. Author manuscript; available in PMC: 2015 Feb 10.

Published in final edited form as: Behaviour. 2012 Jan 1;149(13-14):1339–1365. doi: 10.1163/1568539X-00003019

Table 4.

Test for significance of random effects of the models for bites at the food, N = 68 (number of fixed effects parameters = 5).

	AIC	Log(L)	Cov P	Test	Component tested	χ^2,^*	df	p
1	1540.38	−768.19	2
2	1495.14	−744.57	3	1 vs. 2	Intercept	47.24	1	<0.0001
3	1497.12	−744.56	4	2 vs. 3	Slope	0.02	1	0.8929

AIC, Akaike Information Criterion (AIC); log(L), log likelihood; Cov P, the number of covariance parameters; df, degrees of freedom. The final model is indicated in bold.

Log-likelihood ratio tests.

There was not enough variation in the slopes for the squared and cubic term for time so that when these were added to the model as random effects, the random slopes were inestimable. Therefore, we only tested for variation among individuals in linear slopes.

Model 1 includes the final fixed effects structure with no random effects. Model 2 contains the same fixed effects as model 1 with random intercepts. Model 3 contains the same fixed and random effects as model 2 with random slopes.