Territory is the number one concern for every male hummingbird during mating season. They battle it out for the rights to land, flowers, feeders and breeding. Strength, endurance and courage are key components of a male's development in becoming the top bird. When the males show up in a certain region they'll search out the best locations available. The more we can supply of their essential needs, the more likely a male will stick around. If you have a perfect combination of flowers, feeders, a good structure of trees, and water sources, the more likely you'll attract numerous Males. You can always rate your garden according to how many males return before and during the southern migration.
In this case, one of Ziggy's combatants tested his patience and would return time and again to steal his nectar and sample his garden. Ziggy's keen eye would frequently spot him and the battle would begin, but it wouldn't stop the rebel from return visits.
If you create enough temptation for hummingbirds, it'll be hard for them to resist, even if they have to take on the lead warrior.
N.E. of Edmonton, Alberta. June 2016.