3.1 The relationships between male body size, ornamental traits,
and temperature
Our
analysis revealed that male body mass decreased with increasing ambient
temperature (Table 1). Furthermore, we discovered a significant
interaction effect between male ornament coloration and ambient
temperature, as evident from both Table 1 and Figure 2a. Our findings
indicate that the relationship between male body mass and ornament
coloration was temperature dependent. Specifically, at higher ambient
temperatures, there was a positive association between male body mass
and ornament coloration, while in colder environments, this relationship
became negative (Figure 2b, S2).
3.2
The relationships between male ornamental traits, female body size, and
temperature
We
investigated the relationship between female body size and ambient
temperature, and found no significant correlation (Table 2, Table S4).
Moreover, we did not observe any
consistent
correlation between female body size and male body size (Table 2, Table
S4). However, we did find an interesting interaction between ambient
temperature and male ornament color (MPC1) in relation to female tarsus
length (Table 2, Figure 2a, c, Figure S3). Our results suggest that
larger females tend to mate with males possessing more colorful
ornaments in warmer environments (Figure 2c).
Furthermore, our analysis revealed a positive correlation between female
ornament coloration (FPC1) and size (FPC2) with male ornamentation
(Table S4). Additionally, we observed that ambient temperature acted as
a modulator in the assortative mating based on male and female
ornamentation (Table S4, Figure 2a). Specifically, we found a positive
relationship between male and female ornamentation in warmer
environments (Figure S4a, b).