She usually ends up with a juicy high protein treat, and he helps her gain the strength necessary for nesting and raising his offspring. It's mutually beneficial. Large flocks of blackbirds are looking for places to roost, usually after long periods of night travel from their southern wintering areas. Usually they will stay for only a few days, then continue northward. As with other migrating birds, the males arrive first, and are followed by the females.
Flocks are visually obvious and often very noisy, seemingly attractive targets for predators.
However, flocking makes it difficult for a predator to both go undetected and to be able to focus its concentration on any individual bird. He even suggests one can test this by attempting to keep track of one specific bird as the flock swirls in the air. Early spring nights are just as marvelous for listening to nature. I recently attended a parent meeting at my son's Montessori School in Charleston, where there was a guest speaker, a psychologist who spoke of and described different personalities found in people. It was very enlightening and funny to hear how different people behave.