Most hummingbirds are visitors, passing through on migration, spending a season, then gone. Not the Anna's. This rose-crowned little gem is Tucson's year-round hummingbird, the one holding court at backyard feeders in January, defending its territory in the heat of July, and filling the winter air with its scratchy, buzzing song when every other hummingbird has long since headed south. If you have a feeder up in Tucson, you almost certainly have an Anna's.

Every now and then you spot a bird so striking and full of personality that it stops you in your tracks. For us, the Crested Caracara is one of those birds.

Most hummingbirds make you lean in to see them clearly. The Blue-throated Mountain Gem, known until recently as the Blue-throated Hummingbird, has the opposite problem. It's so large and moves with such commanding presence that the first time you see one at a feeder alongside other hummingbirds, your brain briefly refuses to accept that it's the same kind of bird. The largest hummingbird regularly occurring in the United States, the Blue-throated Mountain Gem doesn't dart and vanish like its smaller relatives. It arrives, it lands, and it holds its ground.