We've assumed this meant when they were caged but what if it has a different meaning? Google that term and this was the answer:
It can start as early as 4:00 a.m. and last several hours. Birds can sing at any time of day, but during the dawn chorus their songs are often louder, livelier, and more frequent. It's mostly made up of male birds, attempting to attract mates and warn other males away from their territories.
These birds keep trying to make a nest outside my window. They've destroyed everything I put up to try and keep them out. I've actually torn down what I have to make it undesirable for them to want to nest. And I just put the correlation together in regards to the politicians and creepy joe. They are an unwanted nuisance that wants to nest where they don't belong. Gotta make it unhospitable for them to leave and relocate. I hear Gitmo is great this time of year!