how long they live before reproduction, reproduction rate, edibility (while you're waiting for them to be tame), in-captivity behavior, what they eat, etc matte

how long they live before reproduction, reproduction rate, edibility (while you're waiting for them to be tame), in-captivity behavior, what they eat, etc matter a lot since they are the variables going into the equation for how many 100s or thousands of years you're going to have to devote to this. Also, if they are basically useless now, most groups won't even realize there's a point to starting to tame them.