Great Horned Owl
The largest owl species in Orange County and also the most common. They prefer large pine and eucalyptus trees with nearby open fields for hunting rodents. If you're walking around a park after sunset and hear their distinct "who" call, you are most likely hearing a Great Horned Owl.
The tufts on top of their heads are not their ears, their ears are located lower and are not symmetrical which helps them hunt during the darkness of the night by locating exactly where any sounds of movement are coming from.