Brown-headed Cowbirds and Parasitic Birds

     The other day walking around at school, I heard a short bubble-bubble-zz.  I had heard this noise before online and from many bird song guides, but I had never heard it in real life.  This noise is made by the Brown-headed Cowbird, which is a bird I have seen many of before, but have never heard their short, sweet noise. These birds like to congregate in big flocks in my pond and backyard.  Rather than take the time to build their own nests and raise their own young, Brown-headed Cowbirds resort to intra-specific parasitism. This means that the female will sneak into another birds nest of a different species and lay the eggs while the parents are out.  The baby will hatch if not thrown out first by the parent of the other species, will be fed and will kick the other young out of the nest.  As a result, these birds might not be the best birds to have in your backyard, and many people refer to them as pests.  Inter-specific parasites will lay eggs in other birds of the same species.  However hard it is to accept them as equals to other birds, I still have to say that I enjoy the short, ecstatic song of the Brown-headed Cowbird.