Is the chicken most common bird?

It's a bit tricky to definitively say that chickens are the *most common* bird, as there are different ways to interpret "common."

* By population: There are definitely more chickens in the world than any other bird species. Estimates suggest there are around 23 billion chickens globally, far surpassing any wild bird population.

* By species: There are over 10,000 species of birds in the world, so it's impossible for chickens to be the most common by species. They are a single domesticated species.

So, depending on how you define "common," you could argue that chickens are the most common bird by population, but not by species.