This California Towhee went foraging in the grass very near a group of sparrows, but quickly distinguished itself, and not only by its slightly larger size and its rusty rump. Unlike the sparrows, which gave a peck or two and then moved on, the towhee jumped up and scratched the spot with both feet, over and over, until it dove in with its beak. To my eyes this was less than efficient, but the bird looked well fed and energetic, so this method must work for it.
The reddish patch on its rump is called the crissum, and this is reflected in its scientific name, Melozone crissalis. Males and females look about the same, and only they can tell each other apart. I haven’t seen one in the park for quite some time and was happy to see it again. They tend to form and forage in pairs, so there’s probably another one nearby.