I'm curious how cowbirds learn the correct song if they are raised by foster parents? For that matter, how do they know they are cowbirds? Marj
That's an excellent question that puzzled scientists for many years! The answer is that they develop a "default" cowbird song regardless of their host. Once they fledge from their host's nest, they have an innate sense to find other cowbirds and form juvenile flocks.
Social interactions and aggression help shape their songs and determine the dominant males. While the dominant males are more attractive to the females, they also attract negative attention from males and risk more attacks. In contrast to many other birdsong species, cowbirds raised in isolation result in a very attractive "default" song since there is no one to challenge the isolated bird to decrease the appeal of his song.