Research Article:  Duangchantrasiri, Somphot & Sornsa, Mayuree & Jathanna, Devcharan & Jornburom, Pornkamol & Pattanavibool, Anak & Simcharoen, Saksit & Kanishthajata, Permsak & Suebsen, Piyapong & Klanprasert, Supalerk & Kumar, N. & Pandey, Chandan & Karanth, K.. (2024). Rigorous assessment of a unique tiger recovery in southeast Asia based on photographic capture-recapture modeling of population dynamics. Global Ecology and Conservation. 

Blog Author: Yasha Chandradeep

Key Takeaways:

  • Southeast Asia, which houses one-third of the world’s tiger population, has been facing the loss of habitats and consequently, tiger populations.
  • This study focused on three wildlife sanctuaries in the Western Forest Complex in Thailand to understand and evaluate the tiger population status and conservation strategies put into place.
  • Tiger populations showed a steady increase between 2007 and 2023, and the birth of 67 tiger cubs suggests that the region can support the repopulation of tigers.
  • The study also found that direct law enforcement is critical to effective conservation strategies.

Historically, tiger populations worldwide have significantly reduced due to poaching and shrinking habitat sizes that are degraded. Previous studies have shown that viable tiger habitats have shrunk by close to 92%. Looking closer at Southeast Asia, which houses about 33% of the world’s tiger population, is still facing challenges in implementing the right conservation strategies. The existing tiger population has been reduced to fragments in Myanmar, Peninsular Malaysia, Sumatra, and Thailand.

Robust conservation strategies can only be implemented after understanding tiger population dynamics, which also take into account the history of the region. This paper summarizes the 18-year study on the Western Forest Complex (WEFCOM) of Thailand and the previous conservation attempts made to provide new and sound strategies to promote tiger conservation and repopulation. The study focused on three key wildlife sanctuaries in the WEFCOM — Huai Kha Khaeng (HKK), Thung Yai Naresuan East (TYE), and Thung Yai Naresuan West (TYW), known as the HKK-TY region. The region is also considered a UNESCO World Heritage Site. In the late 1970s, it was recognized that tigers needed immediate conservation, and village resettlement projects were underway to reduce habitat fragmentation. By the 1990s, this provided a large region suitable for tiger repopulation strategies. With the growing concern about illegal tiger body part trade in the early 2000s, the Thai government also implemented anti-poaching patrols in HKK, which hastened the tiger recovery in the region.

Over 18 years, starting in 2005, a variety of evidence was collected to establish an understanding of the tiger population in the WEFCOM. Annual camera trap images were collected and analyzed to identify unique tigers in the region. These provided insight into their density in the region and their survival rates. Radiotelemetry, which is a method to tag tigers, has provided information about tiger territories, movement, and the crucial understanding of the sex ratios. The researchers found that HKK had higher survival rates due larger prey population and a longer history of protection. The other two regions had higher human activity within them.  This is concurrent with studies that have indicated that in the absence of effective direct protection programs and indirect conservation efforts like “community-based and livelihood-related interventions”, tiger recovery can fail. This suggests that effective and direct law enforcement “should be a critical component” in tiger conservation strategies.

Additionally, between 2013 and 2023, 67 tiger cubs under the age of 1 were photo-captured, suggesting that the region is viable and can support expanding tiger populations. The study also concluded that tiger density in the WEFCOM region was directly linked to the prey population.

Based on these observations, researchers proposed two additional strategies for future conservation programs. First, is to study the “prey population” and understand what impacts those numbers. The second is to study “local colonization and extinction patterns” to identify suitable repopulation habitats across the WEFCOM.  As photographic surveys were found to be expensive, the researchers suggest sign-based surveys (signs that indicate tiger presence like pugmarks, and scats) over multiple years in potential habitats. Lastly, this study lays the groundwork for several future studies across Asia and the conservation of predatory carnivores. These strategies can also go beyond just tiger conservation, but also large cats across fragmented habitats across Asia.

To access the original article click here.

Key Words: Population monitoring, Open CR model, Spatial capture-recapture, Large carnivores, Effective law enforcement, Collaborative Science