Name That Bird

Perhaps this will be regular feature for the next couple of months. I need my readers help with identifying some of the birds here. So far, I've only successfully identified the obvious urban birds of grackles and pigeons.

While at lunch the other day, with my camera handy, I snapped these two pictures of local Yucatecan birds unfamiliar to me. The shots aren't very good and are already enlarged as far they go. No doubt, both of these birds are dead common, but they are new to me. What are they? The yellow one was largish -- bigger than a robin. The black one was larger still -- almost crow size and behaved obnoxiously like a blue jay or steller's jay.

Can you help me name that bird?