Table 2. Results of general linear mixed modelling to test the effect of location within the nest for various structural measures controlling for nest as a random factor in the model.
Materials in the outer nest are compared with those from the upper wall and the base (Fig. 2). The materials from the upper nest wall are also compared to the cup materials (Fig. 2). Values are exponents for changes relative to the characteristics of the upper part of the nest together with accompanying F-values, with the degrees of freedom (df) shown in the row, and p-values in parentheses, also includes the exponent and standard error (SE).
| Vertical (outer nest: upper vs. base) | Wall region (upper outer nest vs. cup) | |||||
|---|---|---|---|---|---|---|
| Variable | Change in base relative to upper (exponent ± SE) | Location (F1,12) | Nest (F12,12) | Change in cup relative to upper (exponent ± SE) | Location (F1,12) | Nest (F12,12) |
| Diameter | 0.291 ± 0.026 | 124.99 (<0.001) | 4.24 (0.009) | −0.184 ± 0.028 | 43.62 (<0.001) | 2.65 (0.052) |
| Bending strength | 0.007 ± 0.001 | 52.78 (<0.001) | 2.70 (0.049) | −0.002 ± 0.001 | 14.38 (0.003) | 1.11 (0.431) |
| Rigidity | 555.5 ± 76.4 | 52.90 (<0.001) | 4.12 (0.010) | −153.0 ± 56.6 | 7.30 (0.019) | 1.06 (0.460) |
| Length of branches | 5.9 ± 2.5 | 5.69 (0.034) | 1.69 (0.188) | −5.27 ± 2.47 | 4.56 (0.054) | 1.59 (0.218) |
| Taper | −0.044 ± 0.015 | 8.82 (0.012) | 1.77 (0.169) | −0.073 ± 0.016 | 20.95 (0.001) | 0.85 (0.605) |
| Number of lateral branches | 0.481 ± 0.140 | 11.74 (0.005) | 4.50 (0.007) | 0.168 ± 0.289 | 0.34 (0.572) | 0.42 (0.928) |
| Hollow samples (%) | 0.223 ± 0.275 | 0.66 (0.433) | 2.22 (0.090) | −0.327 ± 0.349 | 0.88 (0.367) | 0.58 (0.818) |