Although mountain gorillas are now extremely rare, successful conservation work has secured the remaining populations. In fact, they increased during the years of political upheaval in the region (1994-2004). It is believed that both savanna and forest elephants and chimpanzees can still be found in Virunga, along with Okapi, giraffes, buffaloes and many endemic birds. The neighbouring Mount Hoyo area was managed with the park and is home to a population of Bambuti Pygmy people, caves and waterfalls, but since the civil wars, the park has suffered somewhat. Land invasions and intense poaching has challenged the park authorities to the limit, but most rangers have remained active. A reported 92 rangers have been reported killed in action protecting the park from illegal poaching and land acquisition.