Silhouettes aren’t particularly useful for documenting wildlife, so they’re not something I have a lot of experience doing. Still, they can be something interesting to try when the lighting pretty much guarantees you can’t do anything else.
This snowy egret was walking right through the reflection of sunlight on a pond, a situation where there’s no way to get a “proper” photo of it. The result is a failed experiment. The execution isn’t great, but it does seem to show that it would be possible to a very interesting photo this way.
This immature grackle was photographed with just enough foreground light to create a regular portrait or a silhouette depending on the post-processing. It can be good to remember that an underexposed photo that can’t be “saved” as a traditional portrait might make a good silhouette.