Extra bird?

[Jealous Gypsy]

Yep, that's a fledgeling. If you see a baby bird that's partially feathered, and can only fly a little bit, or not at all, but can run around, it's supposed to be on the ground. If you find one that's naked, or just covered in a very thin and non-feather-like down, that's a nestling that needs to go back in the nest.
Birds will often temporarily join groups of other birds in foraging, since a group of other birds hanging out in one place can mean there's food in that place. Your little one might think the guinea chicks are on the ground because they found something to eat.

Haven't seen it since that day, but I hear it farther away from the flock. I love living this life i learn new things every day