For the simple reason that a rhino requires a lot of space on a frog doesn’t. So if you have a lot of rhinos are big animals, you can have fewer individuals and fewer species. On the other hand, if you concentrate on small animals, you can keep more species and more individuals. And that right there, and of course there are many other things besides size it’s determined the amount of space an animal needs, their behavioral requirements, their seasonal behavior, and so on and so on. It’s really a wonderful Persian rug of complications. And that means selection is critical to any long-term propagation program in a zoo. And for that matter in a park.
