If the dev could find a zoo or similar, somewhere with a breeding program, which has a new/recently born Rhino, it really could help amplify the story with the "aww" effect. The amount of money raised from this initial drive would only be relatively small (due to early exchange prices), but would still have an impact for a single site like a zoo or safari park (rather than one of the giant charities). It could still be a high profile story if its one of those in a major world city, you had the cuteness/heartwarming factor sorted, etc