Mayan Pre-Columbian Blackware Effigy Vessel with Bird

I found a note inside of this vessel which identifies is Mayan pre-Columbian from Belize and I know it came from the estate of a pre-Columbian pottery collector. Of course I love it for the head of the bird pointing out from the lip, and the way the lip is shaped to evince the bird's whole body. From what I understand, the blackened surface would have been achieved through the application of a mineral-rich slip, with the monochrome finish designating its use as an everyday object. With its olla form I believe it would have been used for cooking or storage--with the tail of the bird making a useful spout for pouring.

6 1/2" t x 5 5/8" in diameter. Very good condition with no damage or repairs that I can see or feel.