The Los Angeles Audubon Society
Here is another LA organization that might interest you. The LA Audubon Society sponsors bird walks and field trips throughout the area. A complete calendar is available on their site.
From their web site...
The Los Angeles Audubon Society is people dedicated to the enjoyment and preservation of the natural world. Through birding, education and conservation activities in our community, we raise awareness and promote the cause of global environmental protection.
The headquarters, library and bookstore are in Great Hall at the center of Plummer Park, 7377 Santa Monica Blvd, West Hollywood, CA 90046-6694 (on the north side of the street, between Fuller and Vista, six blocks west of La Brea). Parking is free in the large lots at the south and north ends of the park. Or park on Vista.
* Tuesday through Saturday
* 10:00 am to 4:00 pm.