"AWA Only" means that the animals are only those protected by the Animal Welfare Act (AWA). The statistics, charts, and graphs labeled "AWA Only" cover only these species, which entities are required to report on to APHIS.
The AWA applies some minimal protections just to certain species in research facilities. While it does cover dogs, cats, primates, ferrets, pigs, goats, hamsters, Guinea pigs, horses, and most other four-legged mammals, plus marine mammals, it does not apply to:
• Lab mice (genus Mus) and lab rats (genus Rattus) specifically bred for experimentation, which are estimated to be more than 90% of all animals being held in labs. (However, the AWA does apply to all other mice and rats, including house mice, dormice, wood rats, etc., which are rarely used in research.)
• Birds specifically bred for experimentation. The problem here is that no one has ever figured out what birds "bred for use in research" are, so no implementing regulations have been created. Because of this, for all practical purposes, all birds are unprotected.
• Reptiles and amphibians
• Invertebrates: fish, cephalopods (e.g., octopus), crustaceans, insects, worms, etc.
• "livestock or poultry used or intended for use for improving animal nutrition, breeding, management, or production efficiency, or for improving the quality of food or fiber."