An egg can sometimes be traced to its parent species by examining the location of the nest and the type of nesting material present. The nest should not be the sole means used for identification as some birds will take over a partially finished nest of another species.
While egg identification can sometimes be made through more obvious characteristics such as color, size and shape, there are other, more subtle means to help. The amount of gloss to the egg, patterns of speckles on the shell and the number of eggs in the clutch can provide helpful leads.
The time of day the eggs appear in a nest can be a clue to the bird responsible. While the majority of birds lay their eggs in the hours around sunrise, some, such as the American robin, lay at other times of the day.
If an odd egg is found in a nest, it might belong to one of several types of cowbird. Cowbirds lay their eggs in the nests of other birds and leave the foster parents with the burden of raising the cowbird young.
Eggs vary in size--from the jellybean sized, 12.7 mm hummingbird egg to the 120 mm condor egg. Wild bird eggs also come in colors ranging from pale pinks and pastel blues to pure white, deep green, brown and nearly black.
Article Written By Alice Moon
Alice Moon is a freelance writer with more than 10 years of experience. She was chosen as a Smithsonian Institute intern, working for the National Zoo in Washington, D.C., and has traveled throughout Asia. Moon holds a Bachelor of Science in political science from Ball State University.