This one I found while watching the many hummingbirds at the Tucson Audubon’s Paton Center for Hummingbirds in Arizona. They have lots of feeders up for the hummingbirds, but they also include other feeders for the various other species of birds that can be found at the center.
Their diet consists of a wide variety of insects, cactus fruit, berries, seeds, earthworms and small lizards. They will often drink sugar-water from the hummingbird feeders.
Forages on cacti and tree trunks or on the ground. In the trees they probe at the surface, hardly ever to they excavate for their food.
In the picture below the Gila Woodpecker is foraging for insects on a small tree.