Originally Posted by Nutcracker
I'm just going to have a guess on generic principles, to see if I'm getting it right for myself (so don't take this as a reliable answer!):
1 & 2 - thick bill, short tail: my guess the cowbird
3 - thinner bill, longer tail: my guess the blackbird, or a grackle if any on Cuba
Greater Antillean Grackle is very common on Cuba.