Rumors have been spread over many years of how big hawks lifted heavy dogs' weights ranging from 10 to 15 pounds. Surprisingly enough, these have remained to be rumors. Hawks cannot lift more than their weight. Mature adult hawks and other birds of prey can grow up to 3 pounds in their lifetime. Therefore, a hawk can't lift a dog weighing 12 pounds. However, birds of prey may attack a dog weighing 12 pounds and kill it while still on the ground. If it reaches maximum capacity, the hawk drags the carcass to a hidden place to feed and only carries less heavy chunks.