Table 1.
Repeatability compared with heritability calculated by a univariate animal model for onset of nesting and south + west vegetation cover over a nest for female painted turtles, C. picta, from Illinois, USA. Reconstruction of PO pairs, FS and HS links by the maximum-likelihood analysis of genotypes was used as a pedigree. Each row represents a separate univariate analysis. All records available were fitted by the animal model for the ‘total’ dataset and other measures represent environment-specific analyses. The number of individuals (n) for which records were available is subscripted to the number of records. The subscript number in the ‘mean’ column is the raw phenotypic variance for that trait. For vegetation cover after mid-temperature winters, additive genetic variance had to be constrained to be positive, and so this analysis was essentially uninformative (denoted by ‘n.a.’). χ2 represents twice the likelihood difference between a model that contained only the individual effect and the one that also contained an additive genetic effect. The p-value is the result of the LRT and is corrected via the method suggested by Visscher (2006).
| records | mean | VA | repeatability | heritability | χ2 | p | |
|---|---|---|---|---|---|---|---|
| Julian date of the first nest of the season | |||||||
| total dataset | 1965(n = 631) | 161.55(86.04) | 0 | 0.060 (0.026, 0.095) | 0 | 0 | n.a. |
| cold winters only | 395(n = 277) | 166.67(51.62) | 0.038 (−0.078, 0.154) | 0.022 (−0.080, 0.124) | 0.060 (−0.131, 0.250) | 0.220 | 0.320 |
| mid winters only | 531(n = 373) | 158.95(95.57) | 0.084 (−0.047, 0.215) | 0.057 (−0.083, 0.197) | 0.103 (−0.073, 0.278) | 1.054 | 0.152 |
| hot winters only | 693(n = 405) | 160.72(83.07) | 0.131 (0.029, 0.236) | 0.118 (0.014, 0.222) | 0.166 (0.020, 0.313) | 2.138 | 0.072 |
| south + west vegetation cover of the nest | |||||||
| total dataset | 2212(n = 631) | 89.46(1834.375) | 0.043 (−0.126, 0.212) | 0.140 (0.097, 0.182) | 0.043 (−0.126, 0.211) | 0.180 | 0.336 |
| cold winters only | 531(n = 298) | 83.60(1799.968) | n.a. | 0.260 (0.146, 0.374) | n.a. | 0 | 1 |
| mid winters only | 792(n = 444) | 89.28(1807.729) | n.a. | 0.072 (−0.021, 0.166) | n.a. | 0 | 1 |
| hot winters only | 889(n = 421) | 93.12(1848.79) | 0.189 (0.098, 0.280) | 0.181 (0.097, 0.266) | 0.188 (0.104, 0.271) | 2.916 | 0.044 |