In the past decade Namibia's black rhino population have increased by more than 6% and its white rhinos have more than doubled. This is according to the latest State of Rhino report, published by the International Rhino Foundation every September ahead of World Rhino Day on September 22. But the report says wildlife crime is an ever-evolving challenge and requires collaboration and coordination within and between countries, as rhino horn trade is controlled by large criminal syndicates that operate multi-nationally. It says while the act of poaching is often the most visible and most readily understood part of wildlife crime, it is the transport, trade and sale of illegal rhino horn from the protected area, across provincial boundaries and national borders to the end consumer that makes this crime not just possible, but profitable. According to the report it is estimated that the rhino population in Africa is about 18 000, which represents a 12% decline in the past decade.