If 16 ounces feeds 80 and you need to find how many 12 ounces feeds, you need to find how many 1 ounce feeds. so take 80 and divide by 16, you get 5 birds per ounce. now since it is 5 per ounce and you have 12 ounces you multiply 5 by 12 and get 60. Hope this answers you question.