I have been lucky enough to encounter both black and white rhinos in their natural environment in South Africa, Namibia and Kenya. In Namibia I even saw black rhinos mating at night. It would be wonderful if this were still possible into the next century. Following the success of the "Remembering Elephants" project, Margot Raggett and photographer friends have launched a similar Kickstarter project entitled "Remembering Rhinos". Even before the deadline they have raised almost 100,000 pounds.
https://www.kickstarter.com/projects/margotraggett/remembering-rhinos