A new WCS-led study shows how to fully restore a key tiger landscape by re-wilding it with big, juicy prey animals.

Publishing their results in the Journal for Nature Conservation, the authors looked at factors affecting populations of three large ungulates in Thailand’s Western Forest Complex (WEFCOM), a contiguous network of 17 protected areas that together form the largest remaining forest block in mainland Southeast Asia. The 18,000 square kilometer (6,900 square mile) forest is considered a stronghold where tigers have made a comeback due to conservation measures. However, depletion of prey species has prevented a full recovery of these iconic big cats.

The prey animals in the study included gaur (Bos gaurus), a massive wild cattle species that can weigh over a ton; banteng (Bos javanicus) another species of wild cattle with a top weight of over 1,900 pounds; and sambar (Rusa unicolor) a huge deer that can reach well over 1,000 pounds. Across WEFCOM, these large ungulate populations are the preferred prey of tigers, but are threatened by human activities such as poaching and habitat fragmentation.

Using occupancy models, the researchers found that gaur and sambar occupied just 28 and 50 percent of suitable habitat respectively in WEFCOM. Habitat use by both gaur and sambar was lowest in areas closest to human settlements. Banteng have largely vanished from WEFCOM and are now only found in Huai Kha Khaeng (HKK) Wildlife Sanctuary where they occupied 57 percent of suitable habitat.

The authors then modeled the impact of decreasing human activities around nine villages in the core of WEFCOM. This increased predicted suitable habitat to 68 percent for gaur and 75 percent for sambar. In addition, they modeled the extent of potential banteng habitat that still remains in the other 16 protected areas in WEFCOM and found that re-wilding could result in a four-fold increase.

The authors say the options for increasing large ungulates near communities inside and on the periphery of WEFCOM include increasing SMART patrolling, and providing incentives to local communities to reduce poaching. Thailand’s Department of National Parks, Wildlife and Plants Conservation has continually increased investment and training to improve SMART patrolling, but without local support from local people living in WEFCOM, it is not sufficient. Globally, it is increasingly recognized that recovering large wildlife in large ecosystems needs effective law enforcement complemented by local engagement. Local stakeholder involvement in participatory conservation is gaining wide acceptance as an essential component of ecosystem management.

Said Pornkamol Jornburom of WCS’s Thailand Program and the lead-author of the study: “Big cats need big food. This first-of-its-kind study determines where large prey species can be restored to increase the distribution of tigers, and potentially fill a half-full tiger landscape. This critical research will have a significant impact to the future management and recovery of large mammals in WEFCOM and beyond.”