Table 2.
Proportional hazards models relating variation in the annual probability of adult survival to age and inbreeding coefficient (f) in female and male song sparrows. (Positive and negative parameter estimates indicate increased and reduced hazard functions, and therefore increased and reduced probabilities of death, respectively. Nobs and Nmort are the sample sizes of observations and mortality events, respectively. Sample sizes were reduced in analyses including f because individuals with unknown grandparents were excluded.)
| Nobs | Nmort | age | f | age×f | year of birth | |||
|---|---|---|---|---|---|---|---|---|
| Χ2 (p) | β (95% CI) | Χ2 (p) | β (95% CI) | Χ2 (p) | β (95% CI) | Χ2 (p) | ||
| females | ||||||||
| 819 | 311 | 9.1 (0.003) | 0.14 (0.05 to 0.23) | 46.4 (0.008) | ||||
| 640 | 249 | 8.0 (0.005) | 0.15 (0.05 to 0.24) | 0.8 (0.38) | −1.13 (−3.70 to 1.44) | 0.1 (0.83) | −0.20 (−2.05 to 1.64) | 42.8 (0.010) |
| males | ||||||||
| 1309 | 470 | 12.8 (<0.0001) | 0.11 (0.05 to 0.17) | 64.5 (<0.0001) | ||||
| 1031 | 365 | 13.3 (0.0003) | 0.13 (0.06 to 0.20) | 7.7 (0.006) | 2.82 (0.91 to 4.74) | 0.3 (0.58) | −0.33 (−1.49 to 0.83) | 50.1 (0.002) |