Table 2 Parameter estimates from time-dependent Cox proportional hazard models analyzing factors affecting daily chick mortality for the best-fit candidate models from Table 1. Treatment effects are given for control-implanted females relative to cort-implanted females
Variable | coef | SE | p value |
|---|---|---|---|
A. Log rank test score = 14.33, df = 4, p = 0.006 | |||
Maximum daily temperature | −0.11 | 0.05 | 0.050 |
Relative humidity | −0.03 | 0.02 | 0.187 |
Treatment (control) | −7.42 | 2.92 | 0.011 |
Relative humidity × treatment | 0.08 | 0.03 | 0.017 |
B. Log rank test score = 13.51, df = 4, p = 0.009 | |||
Female feeding rate per chick | −0.80 | 0.32 | 0.014 |
Male feeding rate per chick | 1.00 | 0.39 | 0.010 |
Treatment (control) | 1.11 | 0.72 | 0.126 |
Male feeding rate × treatment | −1.53 | 0.62 | 0.013 |
C. Log rank test score = 25.38, df = 8, p = 0.001 | |||
Daily max. temperature | 0.17 | 0.12 | 0.163 |
Male feeding rate | 5.62 | 2.24 | 0.012 |
Treatment (control) | 9.14 | 3.55 | 0.010 |
Female feeding rate | −0.64 | 0.33 | 0.053 |
Daily max. temperature × male feeding rate | −0.22 | 0.10 | 0.035 |
Daily max. temperature × treatment | −0.40 | 0.18 | 0.023 |
Male feeding rate × treatment | −7.59 | 2.96 | 0.010 |
Daily max. temperature × male feeding rate × treatment | 0.03 | 0.15 | 0.043 |