How to Stop Wildlife Poachers OVER the past 20 years, chimpanzees, gorillas and other great apes have declined the most in areas lacking a security force to protect them. Conversely, parks and protected areas with armed guards and anti-poaching patrols - places like Nouabalé-Ndoki National Park in the Republic of Congo, Kahuzi-Biega National Park in the Democratic Republic of Congo, and Volcanoes National Park in Rwanda - have not only retained their ape populations, but have seen population increases. This connection extends beyond great apes. The Albertine Rift in Central Africa has over the past 50 years demonstrated the benefits of a close tie between law enforcement and the survival of diverse species. In Asia, the government's training and deployment of park guards in Thailand's most important reserve, the Huai Kha Khaeng Wildlife Sanctuary, has led to seven years of population stability in tigers and other wildlife, in contrast to dramatic declines in nearby unprotected parks. This only makes sense. We don't leave our valuables unprotected. Guards patrol art galleries and museums to secure our cultural heritage. We should be taking the same approach to safeguarding our natural heritage. The urgency for the training and deployment of guards to protect wildlife across the globe could not be greater. Only last November, Africa's western black rhino officially became extinct. Wild tiger numbers are down to 3,200 from over 100,000 a century ago. Roughly half of Africa's elephants have been killed for the ivory trade since 1987. Sadly, the list goes on. The most effective protection inevitably involves the long-term efforts of committed park rangers patrolling protected areas with the endorsement and support of local communities. Wildlife guards are deployed by the national governments, which gives them the legal authority and mandate to operate and, in some cases, the core financing to do so. Other agencies work in partnership with those governments to give them both technical and financial support to combat poaching. Nevertheless, for many poorer governments striving against the odds to protect their wildlife, outside support for salaries, vehicles and equipment is crucial. At present, support (not including weapons) comes largely from nongovernmental organizations, with their generous private donors, and from national government agencies like the United States Agency for International Development and the United States Fish and Wildlife Service. More money - and the resulting increase in the number and effectiveness of guards - is crucial to the survival of many species targeted by poachers. Fortunately, relatively small investments can have big impacts. In Thailand's Huai Kha Khaeng reserve, 200 rangers cover an area of 1,073 square miles for an annual cost of under $5,000 per ranger. The government pays salaries and, with assistance from the Wildlife Conservation Society, provides rations, equipment and training. Two poachers were sentenced last summer to the longest prison terms to date in Thailand for a wildlife crime - one for four years and the other for five. No high-value poaching episode has occurred in the reserve since. In the Republic of Congo's Ndoki National Park, the conservation society's support for ecoguards over two decades has been essential for the protection of what is arguably Africa's most pristine rain forest - home to critical populations of gorillas, forest elephants and chimpanzees so unacquainted with humans that they approach their fellow primates with no fear. Rangers in Ndoki also enforce agreements that the government has made with logging companies to ensure that hunting and the bushmeat trade do not follow. These rangers toil in landscapes that are frequently remote, physically tough and dangerous. Until we provide the resources and security to safeguard the world's great natural treasures, populations of great apes and countless other species will slowly wink out across the world, and our awe-inspiring natural heritage, the product of millions of years of evolution, will continue its slide into oblivion. Elizabeth L. Bennett is vice president for species conservation at the Wildlife Conservation Society.