Is it possible to optimize the GIF if there are areas on each frame that do not change?

Question

gif

As far as I understand, if you make animation from a video, then the size of the GIF cannot be reduced especially, only by changing the color scheme and reducing each frame. But if I use a composite picture. If a way to remove the background from subsequent frames. For example. I have a forest background that doesn't change throughout the animation gif. And, let's say, against the background of this forest, I will draw a flying bird. It turns out that, in fact, our background is one frame that does not change, but only the second GIF changes - the bird. How can I merge the background and the bird so that the lecha background is not drawn in every frame. And is it even possible?

Answer 1

https://habrahabr.ru/company/io/blog/261083/
you don't have much choice

Answer 2

in fact, as far as I remember, an animated gif just writes not a frame, but the difference between two frames.

Answer 3

When you create an animation in Photoshop, it doesn't matter what layers it consists of. You yourself turn on the visibility of the layers with the background and the bird, i.e. as if for a gif, the background layer can be 1 and is turned on for each frame, and only the object that moves changes.