<Li> Quick growth rate--Fast maturity rate compared to the human life span allows breeding intervention and makes the animal useful within an acceptable duration of caretaking . Some large animals require many years before they reach a useful size . </Li> <Li> Ability to breed in captivity--Animals that will not breed in captivity are limited to acquisition through capture in the wild . </Li> <Li> Pleasant disposition--Animals with nasty dispositions are dangerous to keep around humans . </Li> <Li> Tendency not to panic--Some species are nervous, fast, and prone to flight when they perceive a threat . </Li>

In north america what two animals were early major domesticates