4 DISCUSSION
We conducted a comprehensive analysis of the relationship between
reproductive traits (body size and ornamentation) and female investment
in incubation to demonstrate how ambient temperature modulates female
pre- and post-copulatory mate choice preference in plover populations.
The observed phenomenon could be attributed to the trade-off between
ornamentation and body size in males in colder environments. Our
findings revealed a positive association between male body mass and
ornamentation in warmer regions and a negative correlation in colder
habitats. Larger and more colorful females preferred more colorful males
in warmer habitats, but this tendency was missing in colder conditions.
Furthermore, in warmer conditions, colorful males engaged less in
incubation, and path studies revealed that females compensated for the
reduced degree of male parental care.
However, in colder environments, parental incubation only depended on
ambient temperature. Our data consistently imply that ambient
temperature influences plover mate selection.
4.1
Trade-off between ornaments and morphologicaltraits
varies with ambient temperatures
Body size and mass are often employed as measurements of energy reserves
and can somewhat reflect an individual’s condition or quality . Previous
research has found a positive correlation between sexual signals and
condition indices such as body size and body condition , with some
exceptions . Condition indices are projected to trade-off against other
life-history features, including sexual signals, as a life-history trait
. We found evidence of a
trade-off
between colorful ornaments and body size in males in colder
environments, suggesting that under harsh environmental conditions, male
traits related to self-maintenance may be favored by natural selection .
In contrast, under warmer environmental conditions where the total
incubation requirement is lower and suggests a mild
environment,
males exhibited a positive relationship between body size and ornamental
traits. The relationship between body size and ornaments with ambient
temperature suggests that under harsher environments, individuals may
need to allocate resources to body size due to life-history
trade-offs.