After seeing this I wrote to my birdlist to get an explanation as to what was on this bird and why. Here's the answer I received from Steve Fast. This bird is almost certainly from the NYS Game Farm in Ithaca. This farm raises ring-necked pheasants from eggs to adult in large fenced enclosures. Both males and females are raised. When mature the pheasants are released at various points throughout the state where it is deemed appropriate pheasant habitat exists. They are released in the spring in the hopes that
some will breed to augment the population. Most are shot by pheasant hunters in the fall. The yellow shield is like the blinders on some horses in the old days; in this case it prevents the male from seeing straight ahead and so greatly decreases male to male aggression which would be extremely deleterious in the packed populations in the caged enclosures. The shield is left on as removing it would be cost prohibitive and having it on does not seem to bother the males otherwise. My thanks to Steve and others who replied.