It seems that a Red-shouldered Hawk is hanging around Delta Ponds a lot lately. Not surprising because it is the type of habitat they prefer. They will sit on perches like the one in this photo, 'watching for prey below the forest canopy or at the edge of a pond, sitting silently until they sight their prey below.' (All About Birds) Delta Ponds makes a perfect environment for them.
According to The Cornell Lab of Orthinology All About Birds - "Red-shouldered Hawks are forest raptors. They tend to live in stands with an open sub canopy, which makes it easier for them to hunt. They are not exclusively birds of deep forest, though; you’ll find Red-shouldered Hawks in some suburban areas where houses or other buildings are mixed into woodlands. In the West, they live in riparian and oak woodlands, and also in eucalyptus groves and some residential areas." - https://www.allaboutbirds.org/guide/Red-shouldered_Hawk/lifehistory