- [Narrator] A male white-necked Jacobin takes a break from feeding to rest and digest, but there's no rest for these guys.

White-necked Jacobins are notorious bullies.

(birds chirping) Aggressive and territorial around any food source.

They're always ready for a brawl.

Their metallic blue tuxedos and flared white skirts distinguish them from females who sport a less glitzy green.

This vast difference in coloration makes females a target for constant harassment.

It's almost impossible to feed in peace, but some females have found a clever solution.

And a few of these males have a secret.

At birth, all White-necked Jacobins are born with male coloring.

As females mature, they shed their vivid colors for a more muted palette.

But one out of every five females holds on to their male costume, keeping their bright blue coloring into adulthood.

(bird buzzing) The disguise lets her slip through the crowd unnoticed, at a feeding flower, she can linger as long as she likes.

It's called deceptive coloration, and we're just discovering it may be more common than we think.

And it's why for this female, life is no longer a drag.