3.4 Path analyses
We
conducted a rigorous pathway analysis to explore how ornament traits and
morphometric traits influenced female and male incubation parental care
investment under different temperature regimes (above or below the mean
temperature). We evaluated a large set of 85 candidate models (see
supplementary material for details, Table S5-S8) and identified the
best-supported models for temperatures above and below the mean (Figure
3) based on the lowest AICc values that passed the Fisher’s C test
(Table S5, S7).
Below the mean temperature, we found that females spent less time
incubating than males (t test: t = -13.492, p < 0.001, Figure
3a), and the incubation investment of both males and females was
primarily influenced by ambient temperature rather than male or female
ornament color and body size (Figure 3a, Table S5, S6). In contrast,
above the mean temperature, females spent more time incubating than
males (t test: t = 6.163, p < 0.001, Figure 3b).
Interestingly, we observed that male ornament color was positively
correlated with female incubation investment and negatively correlated
with male incubation investment (Figure 3b, Table S7, S8), while neither
female body size nor male body mass had a significant effect on parental
incubation investment.