The native oaks are critical to wildlife, from insects to bears, providing food and shelter. Thousands of insects eat the leaves, branches, and acorns. In turn these insects feed birds and are especially important to the feeding of nestlings.
Deer and bear rely on acorns to help fatten up for the winter. Entomologist and author Douglas Tallamy states that the single most important thing we can do to help wildlife is to plant a native oak.
https://www.theunion.com/entertainment/doreen-fogle-dont-water-the-oaks/
L.A.’s iconic Mexican fan palms get a lot of attention, but the coast live oak has long been the unsung hero of our urban forest. The area’s most common native tree, it sustained indigenous inhabitants with its edible acorns, and early settlers used its wood to (quite literally) fuel L.A.’s development. Even today, the oak, which can live more than 250 years, doesn’t just pretty up the cityscape. Here, we get to the root of one of L.A.’s most venerable trees.
http://www.lamag.com/mag-features/coast-live-oak/