The visual acuity [sharpness of vision] of a Peregrine Falcon is approximately 8 times more accurate than that of a human. If we humans were to have the comparable eyesight of a peregrine, we would have to have eyeballs the size of tennis balls. The bird with the largest eyeball is an ostrich – eyes are bigger than brain size in ostriches.
Auditory acuity [quality of hearing] is also different. Birds do not have pinnae [ear lobes and curved external structures] to direct sounds into the ear canal. (See the photo to the right of a California Condor auditory canal) They do, however, have ear canals and tympanic membranes with internal auditory ossifications to conduct sounds to auditory nerves. Talking to Cal Sanfort at the Peregrine Fund was revealing to me in that infant birds of prey have closed canals at the time of hatching. I equate this to a protective mechanism at birth. Human Babies and other mammals often do not open their eyes for the first few hours. Bright lights outside of a womb might be too harsh at first. Hearing organs might be assaulted [damaged?]by the loud vocalizations of parental birds.
Sensory efficiency is necessary for birds of prey that may also be prey as well as predator. Owls and Eagles are in the area. How far away can a bird hear other birds?
Can the mother bird hear her chicks from two blocks away? We know she often sits on the Banner Bank Building and keeps an eye on them. If she wants to nap while perching up there, perhaps she can close both eyes and rely on her sense of hearing.
Language studies are on-going to determine the qualities and different vocalizations amongst bird species. The male Peregrine Falcon usually has a higher pitched voice than does the female.
Looking at the ear openings of the California Condors – one can see that they are quite large. They need to hear the sounds of animals being killed to find carrion. As far as the other sensory organs – smell, taste and tactile categories I have yet to determine.
The Harpie Eagle out at the Peregrine Fund has been trained to play reverse catch – throws an object the trainer catches. The trainer also ‘tickles’ his tummy feathers and legs and talons with a feather. The Harpie Eagle seems to like the interaction. This is an imprinted bird – not a wild bird. We know from falconer’s experiences that these birds of prey are very smart and trainable.