A way cool movie on the BBC website, highlights a new finding that these neotropical birds display in pairs, and are presumably unrelated, ruling out kin selection (they don’t talk about this in the article). How this evolved, if it’s not due to kin selection, is unclear, but the authors hypothesize that while the alpha male gets the female, the beta male eventually inherits the mating site. I don’t get it unless the alpha male is always older, or later finds another site, which doesn’t make sense. But anyway, the movie is great . . .

Note, a direct link, with better resolution, is here.