Black-headed was seen very-well and often, over 4 days.

We had a total of 26 species of Psittacids for the trip:

Blue-and-Yellow Macaw
Military Macaw (heard)
Red-bellied Macaw
Red-shouldered Macaw
Scarlet-fronted Parakeet
White-eyed Parakeet
Brown-throated Parakeet
Painted Parakeet
Fiery-shouldered Parakeet
Green-rumped Parrotlet
Dusky-billed Parrotlet (heard)
Orange-chinned Parakeet
Golden-winged Parakeet (heard)
Tepui Parrotlet
Lilac-tailed Parrotlet (not be me)
Black-headed Parrot
Blue-headed Parrot
Dusky Parrot
Blue-cheeked Amazon
Festive Amazon (not by me)
Yellow-crowned Amazon
Orange-winged Amazon
Mealy Amazon
Red-Fan Parrot