Table 2.
Results of GEE analyses examining the effects of condition (i.e., breeding versus hormone-treated), alternatives (i.e., which two alternatives were presented in a particular choice test), and order (i.e., which alternative began the choice test) on choices made in two-alternative choice tests in which call rate or call duration differed between the two alternatives and call effort was allowed to vary freely or was held constant.
| Test series | Acoustic manipulation | Factor | F | df | P |
|---|---|---|---|---|---|
| 1 | Call rate (call effort variable) | Condition | 2.02 | 1 | 0.155 |
| Alternatives | 2.55 | 1 | 0.111 | ||
| Order | 3.01 | 1 | 0.083 | ||
| 2 | Call rate (call effort constant) | Condition | 4.26 | 1 | 0.039 |
| Alternatives | 1.22 | 2 | 0.545 | ||
| Order | 3.13 | 1 | 0.077 | ||
| 3 | Call duration (call effort variable) | Condition | 0.56 | 1 | 0.453 |
| Alternatives | 13.74 | 5 | 0.017 | ||
| Order | 0.13 | 1 | 0.714 | ||
| 4 | Call duration (call effort constant) | Condition | 3.86 | 1 | 0.049 |
| Alternatives | 4.74 | 5 | 0.449 | ||
| Order | 0.06 | 1 | 0.801 |