24 ILLINOIS AUDUBON BULLETIN 
Seeing What Is Really There 
Several winters ago at Illinois Beach State Park, a bird quickly flew by a 
small group of birders. All called the bird a Goshawk, but some said its 
upperparts were brown, and others said they were gray. How could different 
observers, all capable and experienced, see different colors on a bright, sunny 
day? Perhaps it had something to do with the fact that they had only a very quick 
look, which always causes problems. But the eye can be fooled even under more 
leisurely circumstances. A few years ago, a Spotted Redshank was reported in 
New Jersey. This is a dark Eurasian shorebird with red legs, about the size and 
shape of a Greater Yellowlegs. The bird was usually seen at a considerable 
distance through telescopes. Although quite a number of people identified it as a 
Spotted Redshank, it was finally determined that the dark color was oil, and the 
bird was a Greater Yellowlegs. But what about the apparently red leg color? 
Well, those of you who examine birds carefully may have noticed that the leg 
color of Yellowlegs varies some from yellow to a more orange-yellow, and that 
late in the day, as the sunlight gets redder, so do other colors. Furthermore, the 
chromatic aberration in some telescopes can give a red tint to the leg color. 
These examples and others show that what you see is not always what is 
really there. What you see is affected by distance, duration, angle and quality of 
the light, and other factors. It is impossible to discuss all the possibilities, but the 
following examples should give you an idea of the kinds of observational factors 
that can cause field problems. 
Size: I often hear statements such as ‘‘It was too big to be a crow.”’ We all get 
impressions of the size of a bird seen at a distance, but those impressions are 
largely subjective unless the bird is next to a familiar object. Apparent size 
depends on apparent distance, and that is often difficult to judge. I have been 
fooled so often on the size of a bird that I believe the only reliable description of 
the size of a bird is one that compares it to other nearby birds or objects. 
Misimpression of size is not limited to instances where the bird is far away, 
either. From a blind, I once watched a Least Bittern only two feet away that I at 
first thought must be a pygmy or runt bird because it seemed smaller than a 
Robin. Only when the bird returned to its nest, at my accustomed viewing 
distance, could I see it was of normal size. 
Light: Trying to see colors on a bird against an overcast sky is a frustration 
known to every birder. But strong, bright sunlight can also cause problems by 
washing out colors. I find that bright sunlight sometimes makes the black 
wingtips of adult gulls almost impossible to see at a distance, for example. The 
angle of the sunlight is often important. I have before me two slides of a pair of 
Western Gulls standing together. They were taken a few minutes apart, from the 
