Looks like a Brewer's Sparrow. As seems to be my curse with the tweeters, something in the way or shadowing the bird.
Terr male singing
Small bird on Mojave Yucca
Flying from Creosote bush to cactus to Yucca.
San Diego County, California, US
Brewer's Sparrow (Spizella breweri) is a small, slim species of American sparrow in the family Emberizidae. This bird was named after the ornithologist Thomas Mayo Brewer.