Final answer:
A junco with less CORT and bolder behavior may have higher fitness, allowing it to better survive and reproduce in a campus environment. This advantage could be an adaptation that has evolved through natural selection, leading to a population predominantly composed of bolder juncos.
Step-by-step explanation:
A junco that produces less CORT, a hormone related to stress response, and exhibits bolder behavior may have a competitive advantage in a campus environment because such traits can translate to higher fitness. Fitness, in evolutionary terms, refers to an organism's ability to survive and reproduce in its environment. A bolder junco is likelier to explore new food sources, evade predators, and secure territories, which are advantageous for survival.
Due to natural selection, the bolder juncos with these beneficial traits are more likely to survive and reproduce, passing on these traits to their offspring. This is an example of an adaptation—a trait that has evolved through natural selection to increase the likelihood of an organism's survival and reproduction in its particular environment. Over time, a population of juncos that embodies bolder behavior and lower CORT levels could become predominant in the campus ecosystem, as these adaptations allow them to be more successful than their less bold counterparts.