First, ensure that the animal is truly orphaned. Rabbits for example, leave their young unattended for much of the day. Call before handling an animal unless it is in harms way (dog, cat, etc.).
If an animal is truly orphaned or injured, put it in a small box in a warm, quiet setting. This might include a heating pad , on low setting, below the box or container. Do not handle, stress can be lethal and you are perceived as a predator. If it is a raptor (taloned bird), call a Rehabilitator. They are trained in handling of dangerous birds. If you must handle the bird, use thick welders gloves. Warmth is important for all injuries and if a dog or cat is involved, medication will be needed.
You can place a fallen bird back in it's nest. If the nest is too unstable, it can be supported with twist ties, extra sticks, etc. and if it is in an inappropriate spot, it can be moved within 10 or 20 feet to a better site.
Reptiles are a special situation. Many in Arizona are venomous. Unless you are sure it is not dangerous, leave it alone. Reptiles can go longer periods without food so don't try to feed it. If you're unsure about handling it, call the number below for aid. Also, many in Arizona are protected species and require special permission for handling.
If you don't reach a veterinarian or Rehabilitator within a few hours, you can offer non-reptile species some warm sugar solution. Small birds need only a few drops, using a clean small brush dipped in the solution and touched on the side of the beak, drop by drop. They can aspirate easily. Small animals usually need to be fed every 1-2 hours. Do not put water bowls in with the animals as they tend to spill and get the area wet and cold.
Birds often fly into windows. Some are just stunned and need 20 minutes or so to rally. Place them in a shoe box or container, allow them to warm up in a safe area and then if they can't fly away, call a Rehabilitator.
Phone Numbers for Wildlife Help:
Erin McNulty, DVM 480 981-8387 (Brown Road Animal Clinic)
Toni Arena, Wildlife 480 982-6624 (Gold Canyon & East Valley)
Reptile Removal/Information 480 894-1625 (24 hours/day,7 days/wk)
Adobe Mountain Wildlife Center 623 582-9806 (Far West Valley)
East Valley Wildlife 480 899-1513 (Referrals)
Oasis Wildlife 480 396-6532 (Raptors only)
Southwest Wildlife 480 471-9109 (Entire Valley)
Arizona Covey Quail Rehab. 602-996-1934
Cry in the Wilderness 602-310-0735
Liberty Wildlife 480-998-5550
Raptors, Inc. 602-404-8743
Wild at Heart 480-595-5047