Up until a few decades ago, biologists believed that as many as 93 percent of songbird families practiced monogamy. However, since the development of DNA fingerprinting in the 1980s, we now know some birds that appear to be devoted mates will stray.
This earth-shattering realization came about quickly. For example, by 2002, researchers discovered that up until that time a meager 14 percent of the songbirds tested were truly monogamous. Research has shown 19 percent of the nests of supposed monogamous birds are home to at least one nestling that was sired by a father different from the rest of its nest mates.
A few of the backyard birds that are promiscuous are the eastern bluebird, ruby-throated hummingbird, house finch, and red-winged blackbird.
It would appear that some of our backyard feathered neighbors live soap opera lives.