system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why don't different kinds of birds reproduce and create "mixed breeds" like dogs?

Why aren't there finch-pigeons and crowbins?
gpt
Dogs are all the same species.   Two random birds of different species are very unlikely to be compatible.  Their mating rituals don't match up, eggs aren't viable due to X or Y or Z, mismatched number of chromosomes - there are a lot of things that can go wrong there, and they've had millions of years to accumulate such differences.  Dogs, on the other hand, were all wolves quite recently in comparison, and look much more different than they actually are genetically.