Table 2. Effects of the different predictor variables on performance.
| Predictor | Estimate | s.e. | t | P MCMC |
|---|---|---|---|---|
| (Intercept) | 0.108 | 0.173 | 0.624 | 0.5554 |
| Species | −0.042 | 0.034 | −1.237 | 0.2452 |
| Condition | 0.019 | 0.003 | 7.402 | 0.0001 |
| Difference | 0.042 | 0.011 | 3.740 | 0.0001 |
| Ratio (ln) |
0.101 |
0.033 |
3.027 |
0.0024 |
Condition refers to three experimental conditions Food, Pebbles and Food replaced; difference refers to the absolute difference between the two amounts presented and ratio (ln) to the ln-transformed ratio between the two quantities. Parameter, s.e. (standard error) of the Estimate and t-value (test statistic) were obtained from a GLMM analysis. A Monte-Carlo-Markov-Chain procedure was used to approximate the significance levels of the parameter estimates (PMCMC).