Red-wing blackbirds mislead us. On one hand, their noisy and busy behavior in the cattails during mating season seems directed at keeping other males away from each of their small aggressively defended territories. Males have many female mates. But here is the curious thing that I read on the Cornell Lab of Ornithology web site: up to half of the baby birds have a different father. I think that something else is happening in those cattails than males trying to keep a harem of females for themselves. Either the males are spectacularly unsuccessful at defending their territory or something else is going on. Perhaps a hint is found in the bird’s fall and winter behavior. All the males gather together in large same-sex flocks, spending most of the year with each other, eating and sleeping together. Maybe they are a bit more cooperative during breeding season too? Or maybe the females are controlling the shots despite all the noisy male behavior.