Bird Nest

While snacking at a white mulberry tree that some birds "planted" beneath one of our cedar trees, I found what I believe to be a Chipping Sparrow nest. There are two small blue eggs and one bigger speckled egg. When I saw it, I immediately thought it must be a Brown-Headed Cowbird egg.



I saw (and heard) a pair of these birds in our yard this spring. Google results came up with two pictures that look remarkably similar to what I found: Cowbird Egg in Chipping Sparrow's Nest and Chipping Sparrow nest with a Cowbird egg. The All About Birds information page on the Chipping Sparrow (linked above) even shows a picture of a cowbird egg in a chipping sparrow nest. Now, the question is, do I throw away the cowbird egg or watch and wait...?

Update: In response to my question, there have been some hilarious comments and helpful ideas at the 4Real Forum.