system
Given the following post, respond as if you're commenting on Reddit:
human
When baby birds are in the nest, where does their excrement go?

Does it leak through or soak into the nest, does the mother remove it somehow, or is there just not enough of it to matter before they fly away? Is there much difference between species?
gpt
Depending on the bird, it can go to several places.

Most smaller birds actively remove fecal matter from the nest region, potentially to avoid alerting predators to the nest location. some carry it, other eat it. Some species even excrete feces in a somewhat sturdy membrane called a fecal sac to facilitate this behavior.

Some baby birds also instinctively back up and aim their poo over the side of the nest out out of a cavity nest.

Some (notably birds of prey, herons and their allies and pigeons) just go wherever and let it accumulate.