Another beautiful nest in the berries, this one has a cowbird egg. The Brown-headed Cowbird is a brood parasite,and does not build their own nest, interestingly there are 220 different birds that they utilize to raise their young. They only lay one egg per nest but will lay up to 40 eggs a year. They have been known to chase the nest's egglayer off her nest to lay the egg and they usually pick species that have smaller eggs! Some of the bird hosts recognize the egg as unwelcome and will get rid of it or abandon the nest, but many do not and raise the baby cowbird as their own; this can sometimes be detrimental to the host's own fledgelings. Only 3 percent of cowbirds are fledged- successfully. Curious. I wonder if the diet for the young cowbird is of no consequence or are all baby birds fed an identical diet. Update.. at least two have fledged from the nest, just got a quick look so as not to disturb, not sure if one was the cowbird. By the way.. have learned that the chipping sparrow nest (which this was) is the most frequently parasitized nest.