Table 2. Results of the ANOVAs testing for sex and patch differences in discriminable chromatic (ΔSvar) and achromatic (ΔLvar) variability and corresponding Ordered Heterogeneity tests testing for a positive relationship between levels of variability and sexual dichromatism.
| sex | patch | sex x patch | Ordered heterogeneity tests sexual dichromatism vs. variability | ||
| Robin Erithacus rubecula | ΔSvar | F1,59 = 0.02, p = 0.88 | F1,59 = 11.07, p = 0.0015 | F1,58 = 0.54, p = 0.46 | 1) |
| ΔLvar | F1,59 = 0.39, p = 0.546 | F1,59 = 1.53, p = 0.22 | F1,58 = 0.8, p = 0.389 | 1) | |
| Blackbird Turdus merula | ΔSvar | F1,155 = 2.93, p = 0.088 | F3,155 = 10.08, p<0.0001 | F3,152 = 2.01, p = 0.114 | rsPc = 0.99, k = 4, p<0.001 |
| ΔLvar | F1,155 = 4. 54, p = 0.0347 | F3,155 = 2, p = 0.115 | F3,152 = 0.8, p = 0.524 | rsPc = −0.70, k = 4, p>0.95 | |
| Blackcap Sylvia atricapilla | ΔSvar | F1,194 = 8.78, p = 0.0034 | F2,194 = 3.57, p = 0.026 | F2,192 = 2.81, p = 0.062 | rsPc = 0.48, k = 3, p>0.05 |
| ΔLvar | F1,194 = 2.17, p = 0.142 | F2,194 = 2.69, p = 0.070 | F2,192 = 2.03, p = 0.331 | rsPc = 0.46, k = 3, p>0.1 | |
| Great tit Parus major | ΔSvar | F1,195 = 0.44, p = 0.5 | F3,195 = 24.38, p<0.0001 | F3,192 = 2.56, p = 0.056 | rsPc = −0.39, k = 4, p>0.8 |
| ΔLvar | F1,195 = 1.16, p = 0.281 | F3,195 = 1.22, p = 0.301 | F3,192 = 1.14, p = 0.331 | rsPc = 0, k = 4, p = 0.5 | |
| Blue tit Cyanistes caeruleus | ΔSvar | F1,143 = 0.38, p = 0.53 | F3,143 = 21.38, p<0.0001 | F3,140 = 1.57, p = 0.19 | rsPc = 0.39, k = 4, p>0.1 |
| ΔLvar | F1,143 = 0.22, p = 0.639 | F3,143 = 5.99, p = 0.0007 | F3,140 = 1.68, p = 0.172 | rsPc = 0.19, k = 4, p>0.2 | |
| Greenfinch Carduelis chloris | ΔSvar | --------- | Males: F4,200 = 3.07, p = 0.0173 | F4,295 = 4.75, p = 0.001 | Males: rsPc = 0.59, k = 5, p<0.05 |
| Females: F4,95 = 10.10, p<0.0001 | Females: rsPc = 0.50, k = 5, p>0.05 | ||||
| ΔLvar | --------- | Males: F4,200 = 5.07, p = 0.0007 | F4,295 = 2.85, p = 0.024 | Males: rsPc = 0.099, k = 5, p>0.4 | |
| Females: F4,95 = 4.87, p = 0.0013 | Females: rsPc = 0.49, k = 5, p>0.05 |
Significant terms are depicted in bold.
1)
Ordered heterogeneity tests were not computed for robins as only two patches were measured. In this case chromatic variability (ΔSvar) was higher for the more sexually dichromatic patch (breast) as indicated by Figure 1A, Table 1, and the significant “patch” factor; this was not the case for achromatic variability (ΔLvar) where there was no significant difference in variability between the two patches (Fig. 1G).