It's strange though, or perhaps my brain isn't functioning well tonight! It says
"Males claim territories to have a monopoly on breeding, and typically show less aggression toward trespassing females."
which seems to contradict with
"Compared with drab females, vibrant females with male coloration faced less social harassment from both male and female birds."
And then we have
"The data suggests that these more aggressive females with the male-like plumage are better at defending a key food resource,"
so they don't just look different from brown-feathered females, they act differently as well.