Interesting. You know how I look at parrots and predation personally? My analogy is this: We drive every day; to work, the supermarket, etc. We probably see a car accident every day. Parrots live under a similar threat of predation. Do we worry about the very real threats of being on the road? Drunk drivers, people running red lights. No. We follow the "rules" of the road and therefore we drive relaxed, listen to the radio, etc. We don't have stress, anxiety, or panic attacks behind the wheel. Well, the rules parrots live by keep them safe in much the same way. Rules that comprise their social behavior....having lookouts, flocking (many eyes, large numbers confusing to a predator trying to single out one bird, etc.).
This is an interesting post by Dr. Don Brightsmith, head of research at Tambopata:
"Recently I was asked what animals prey on parrots in the wild. I guess the short answer to that is . . . not much. In general parrots are quite wary and do a number of things to make sure that they are not captured by predators. They usually feed in groups high in the tree canopies. The high perches and large groups ensures that there are many eyes to spot predators and then an easy escape as they drop from the tall trees. Parrot nests also seem to be chosen to reduce the risk of predation. Most species in predator rich environments, especially the macaws I work with, prefer to nest in high trees in relatively exposed spots from which the adults can watch for danger and take flight quickly if needed. Those species that nest in the forest understory where they are more vulnerable take great precautions to avoid being captured when they return to their nests. I have watched three such species in the wild as they approach their nests, the Cobalt-winged Parakeet, Tui Parakeet and the Gray-cheeked Parakeet. All three of these birds are normally loud and raucous (those who own them as pets will back me up on this one I am sure). They call constantly when in flight, and usually even continue to chatter while feeding. But when they return to their nests it is a very different matter. They arrive and perch in a tree some 30 to 60 ft or more away from their nests. From this point on they are almost completely silent. They fly quietly to a perch in the canopy directly above the nest, never flying directly to the nest entrance. From their vantage point in the canopy they check the area then slowly descend through the dense tropical vegetation until they arrive at the hole in the termite nest or tree hole that they call home."
We tend to emphasize parrots as prey animals but even a bald eagle can fall prey to a bobcat, or a vulture to a lion. Birds in general are delicate - and they know it, even if instinctively (like a horse that doesn't step into unsure ground). Their light bodies, hollow bones, etc. cannot withstand a blow. Mammals, on the other hand can be thick boned and heavily muscled. Flight, as well as being up high is their protection as well as security (possibly interpreted as height dominance by people). The benefit of having a crop and gizzard is that they can gulp down food, quickly leave the ground, and chew it (internally) later. I've seen parrots eat clay not on the lick but in a tree. They chip off a piece and fly into a tree to eat there...first at the lick and then to a tree (hopefully you can see the clay in some of their beaks in the pics).