4 week old chicks growing at different speeds (also what gender?)

[Pigeony]

Hello I am also concerned about chick #3, regarding your questions, #3 is much smaller than the other two.

Since I got them as day old chicks, it has barely grown much bigger. It has started develop its wing feathers as you can see, but at a very slow speed. In its first week, it got pecked on by another chick on its nose and had a little injury there, which healed up. It hasn’t had pasty butt or any digestive issues. Its toes look like normal baby chick feet, but it is definitely lighter than others. The keel feels around the same prominence as the other two. I have attached some more photos. It hasn’t got any tail feathers or any other feathers, except for its small wing feathers.

Behaviour wise, it seems to be acting normal, it’s just so much smaller than its two hatch mates pictured. It comes to me & enjoys treats when I feed them - thyme and meal worms. However there is one other chick that keeps picking on it and attempting to peck #3's feathers. I've since isolated that chick to try and stop this behaviour.

I will definitely try the electrolytes and scrambled eggs. Should I just feed it to the little chick, or give it to all the chicks?

That's good that it doesn't have any glaring signs of a health struggle other than being small and underdeveloped, I would just support it as best you can then wait and see. The electrolytes and scrambled eggs can be offered to all 3 chicks or just the little chick, your preference. It won't hurt the healthier ones to get a little boost themselves.