Good point on the camo. The whole point of camouflage is to break up your outline. I’ve found that while camouflage is great, anything you can do break up a silhouette is immensely helpful.

On the smell note, different birds have different levels of smell. I have read studies where individual petrels have found their burrows and recognized their chicks in a colony of tens of thousands of birds through the sense of smell. I think Vultures also use smell to find carrion. Overall though, I don’t think it is nearly as important as in mammals.

True story about deer not seeing colors – hunters wear camo because deer can see solid patterns against the random background of the woods. What deer lack in eyesight they make up for is smell, though.

I once heard that if deer had the eyes of a Turkey, we would never know they existed.