This bird changes color without molting.
The hummingbird tanager hides one of the most curious mechanisms in Brazilian ornithology.

Hello Photographers!
There is a bird that visits the flowers of the Atlantic Forest with the same delicacy as a hummingbird, but it hides a secret that most photographers don't know: it changes color without changing its feathers.
The Blue-crowned Tanager ( Cyanerpes cyaneus ) is one of those field encounters that makes you stop and take a moment to stop. The adult male is a vibrant ultramarine blue with bright red legs—a combination that seems unreal until you see it with your own eyes.
But it's after the breeding season that things get interesting.

The eclipse
In autumn and winter, the male of the hummingbird tanager turns green. Not just any green—a green almost identical to that of the female, which is already naturally greenish. Ornithologists call this eclipse plumage .
Most birds that go through this molting process: they replace their old feathers with new ones. But the hummingbird tanager does something different.
The trick of the tricolor feathers
The male's feathers are tricolored . If you could look at a feather under a microscope, you would see three layers:
Base : black
Middle : blue
Tip : green
During the breeding season, the green tip remains intact—and the bird appears... green. As the months go by, this tip naturally wears away due to daily wear and tear. And when the green tip disappears, what appears? The blue in the middle.
The hummingbird tanager doesn't molt. It reveals a color that was previously hidden.
It's as if the bird is wearing a green cloak that time gradually wears away, revealing its true nature.
Why does this matter?
For us photographers, understanding this mechanism completely changes how we read the scene.
If you find a male that is partly green and partly blue, it's not a sick bird or a hybrid. It's a male in transition—and capturing that moment is capturing something that few photographers realize exists.
The hummingbird-tanager isn't actually a hummingbird. Its name comes from its habit of visiting flowers with its long, curved beak, but it's a passerine bird from the Thraupidae family—the same family as tanagers, honeycreepers, and finches. It's a beautiful case of convergent evolution: two different bird families that arrived at similar solutions for accessing nectar.

Where to find
The hummingbird tanager lives in various types of forests — from the Amazon to the Atlantic Forest. It follows mixed flocks of birds, frequents forest edges and undergrowth, and appears in places where it is not seen at other times of the year because of its local migrations.
If you photograph in the Atlantic Forest, pay attention to the tubular flowers and fruit trees. That's where she appears, with the calmness of someone who knows exactly where the nectar is.
The next time you see a vibrant blue amidst the green of the forest, look more closely. It might be a hummingbird tanager showing what most people never notice: that sometimes the most beautiful color is the one that was hidden all along.

If you've ever photographed a hummingbird tanager—especially one undergoing plumage transition—tell me about your experience. I love hearing what you all find out there.
And if you don't already know this species, here's a tip: on your next outing, look for it among the flowers and mixed flocks at the edge of the forest. It's small, but when it appears, you won't forget it.