Table 1.
Factors explaining the cooperative investment of helpers. Full models included the observation period (before or after takeover) and the type of takeover (inheritance or dispersal) as fixed factors, the interaction and the individual identity as random factor. All displayed models are based on N = 80 observations on n = 16 individuals.
| estimate | t/z-value | p-value | |
|---|---|---|---|
| territory defence against predators | |||
| intercept | 0.38 ± 0.18 | 2.13 | 0.04 |
| period (before/after takeover) | 0.92 ± 0.24 | 3.80 | <0.001 |
| takeover type (inheritance/dispersal) | 0.56 ± 0.22 | 2.50 | 0.03 |
| period × takeover type | −0.83 ± 0.32 | −2.60 | 0.01 |
| territory defence against conspecifics | |||
| intercept | −0.78 ± 0.31 | −2.54 | 0.01 |
| period (before/after takeover) | −0.80 ± 0.40 | −2.00 | 0.046 |
| takeover type (inheritance/dispersal)a | −0.62 ± 0.53 | −1.18 | 0.24 |
| period × takeover typea | −1.07 ± 0.92 | −1.155 | 0.25 |
| territory maintenance | |||
| intercept | 0.19 ± 0.0.20 | 0.91 | 0.36 |
| period (before/after takeover) | 0.69 ± 0.17 | 4.00 | <0.001 |
| takeover type (inheritance/dispersal)a | −0.03 ± 0.36 | −0.08 | 0.94 |
| period × takeover typea | 0.02 ± 0.35 | 0.05 | 0.96 |
aThese terms are displayed with the parameter estimates at the point they were dropped from the model.