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.