I saw this cute little bird in a tree along one of the Delta Ponds. Its size, shape and bill are like a Chick-a-dee or a Bushtit. My guess would be a Bushtit. I loved how the branches created a wonderful frame for the bird.

Following is a link that leads me to believe the bird to be a Bushtit. It mentions that they are often seen with other birds as they forage. That was the case with this one. It was with a Bewick's Wren and perhaps another kind of bird. This quote is from 'The Cornell Lab of Orthinology - All About Birds': "Bushtits are sprightly, social songbirds that twitter as they fly weakly between shrubs and thickets in western North America. Almost always found in lively flocks, they move constantly, often hanging upside down to pick at insects or spiders on the undersides of leaves. Flocks of Bushtits mix with similar small songbirds like warblers, chickadees, and kinglets while foraging. Bushtits weave a very unusual hanging nest, shaped like a soft pouch or sock, from moss, spider webs, and grasses." See the photo at this link, which does look like the bird I saw - https://www.allaboutbirds.org/guide/Bushtit/id