Males and females generally arrive at about the same time, but it is the male that is the dominant bird that claims his territory. He stakes his territory by making his presence known in or at a certain cavity or cavities. Once he has decided which cavity or cavities he wants, he will defend it against all other males. This is the reason it is a good idea to have porch dividers on houses that have connecting porches. This will help to eliminate a single male from dominating a complete floor or side of the house.
Males defend their territories with a variety of actions.
These include a vocalization in martin language proclaiming his area and aggressively fighting other males to the point of locking-up and falling to the ground. When a male has successfully defended his territory, he will sing to attract a female. Females have full say in whose mate they will be. Her choice is simply made by entering his territory. Upon his acceptance she will start spending a lot of time with him.