The tiger population at a wildlife sanctuary in Thailand is recovering as a result of protection efforts – the only area in Southeast Asia where tiger numbers are on the up. The government of Thailand set up an "intensive patrolling system" in 2005 at the Huai Kha Khaeng Wildlife Sanctuary in a bid to save the tiger population in the region.

A study has now found its efforts have paid off. Over a period of eight years, researchers monitored the population with 137–200 camera traps. More than 21,000 "trap days" eventually identified 90 distinct individuals living in the region. The findings were published in the journal Conservation Biology.

Tigers in Southeast Asia are critically endangered. Globally, it is thought there are as few as 3,200 living in the wild. They are threatened by habitat loss and illegal poaching – their fur is sold and body parts are often used in traditional East Asian medicine.

However, the Thai government working with the Wildlife Conservation Society sought to change this, establishing a patrol system to curb the poaching of both tigers and their prey. The team used models to estimate annual abundances from the camera trap data and found numbers were improving.

"Possibly because of poaching pressure, overall tiger densities at Huai Kha Khaeng were 82–90% lower than in ecologically comparable sites in India," they wrote. "However, intensified patrolling after 2006 appeared to reduce poaching and was correlated with marginal improvement in tiger survival and recruitment."

They said that while the results show population recovery of this low-density tiger population may be slower than initially anticipated, the news is positive. Researchers said it will be between 10 and 15 years before populations reach optimal densities needed to support higher tiger numbers.

Somphot Duangchantrasiri, from the Wildlife and Plant Conservation, Thailand, and lead author of the study, said: "The protection effort is paying off as the years have progressed, as indicated by the increase in recruitment, and we expect the tiger population to increase even more rapidly in the years to come."

Joe Walston, WCS vice president of field conservation said: "This is an outstanding conservation success coming from an area where wildlife has been struggling for some time. The result to date is reflective of the commitment made by the Thai government and its partners to Thailand's natural heritage. And despite the considerable gains made already, we believe the future looks even brighter."