The American cowbird has characteristics a lot like cuckoo; I forget what the native species is here, but the the species it victimizes has a nest built, and the cowbird lays it's egg in the same nest. The original bird doesn't just toss the wrong egg, it literally abandons the first nest and builds a new one on top, and again lays eggs, to which the cowbird adds another. This cycle can happen several times before the host bird gives up and ends up raising a cowbird young. I remember this from decades ago in a university course; some details are missing.