Not just saying this because I’m a bird furry but it’s hard to understate just how unfunny “birds aren’t real” is as a bit. “Gingers have no soul” level joke
i feel like i'm not allowed to talk about how much i dislike this joke because, as a bird person, i think people are going to assume i have a personal moralistic problem with "birds aren't real". but i just don't like any joke where the punchline is that you have already heard the joke before.
"birds aren't real" is in the same category as "the cake is a lie", or "all your base are belong to us", or "then i took an arrow to the knee". it's a joke people say not to be funny, but to be joking.