- Camera traps are already a common tool for monitoring the distribution and abundance of wildlife species in remote areas.
- They have also been known to inadvertently capture images of human activities, and this “by-catch” has been used to assess the presence of poachers and other criminals operating within protected areas.
- Camera traps are being put to use right now for that express purpose in forest sites in India, Malaysia, and the Russian Far East, but, until now, no study has yet assessed the effectiveness of this approach.
Forest destruction and degradation have had a severe impact on biodiversity in the Asian tropics in recent decades, leading to the creation of several protected areas to help conserve threatened wildlife and ecosystems.
Many of those nature preserves lack adequate protections, however, especially in large, remote landscapes that are difficult to patrol. Conservation officials still rely largely on patrols by park staff to identify illegal human activities such as poaching, unpermitted fishing, and illegal logging, but the effectiveness of patrolling in many tropical Asian protected areas is further limited by resource scarcity as staff, equipment, and fuel are often in short supply.
There are a number of technologies that could improve the detection of wildlife crime, including conservation drones, acoustic traps, and infrared-triggered remote camera traps. Of these potential tech solutions, camera traps, in particular, are coming to be seen as a relatively low-cost means of improving wildlife crime detection and supplementing field patrol efforts.
Camera traps are already a common tool for monitoring the distribution and abundance of wildlife species in remote areas. They have also been known to inadvertently capture images of human activities, and this “by-catch” has been used to assess the presence of poachers and other criminals operating within protected areas. Camera traps are being put to use right now for that express purpose in forest sites in India, Malaysia, and the Russian Far East, but no study has yet assessed the effectiveness of this approach.
An international team of researchers set out to address that knowledge gap by examining the use of camera traps in the three Wildlife Sanctuaries of the Bangladesh Sundarbans: East Wildlife Sanctuary (312 square kilometers or about 77,100 acres), South Wildlife Sanctuary (370 square kilometers or 91,430 acres), and West Wildlife Sanctuary (715 square kilometers or 176,680 acres). Just 40 staff with the Bangladesh Forest Department are responsible for patrolling all three of these protected areas, which total nearly 1,400 square kilometers (345,948 acres) in total land area.
Antony Lynam, Conservation Scientist for the Wildlife Conservation Society and a coauthor of the study, has been using camera-traps for detecting tigers and other cats for two decades. “Camera-trapping has helped researchers identify and count tigers and other animals with distinctive markings,” he told Mongabay.
”In this study, the target was reversed, and it was humans that were targeted. Camera-traps were set so as to maximize detections of forest intruders, which were places like junctions of streams where boats move through the forest to fish, collect crabs and nypa leaves, and to hunt, inside and outside of the wildlife sanctuaries.”
Lynam and team called the sanctuaries “prime examples of protected areas where detection of wildlife crime is difficult due to limitations in patrol effort relative to the size of areas that require monitoring” in an article summarizing the results of their study published in the journal Biological Conservation.
The researchers added that the key species of conservation concern in the sanctuaries, a “maze of interconnecting waterways and low-lying, muddy and densely vegetated mangrove islands,” are tigers (Panthera tigris), Gangetic dolphins (Platanista gangetica), and an aquatic bird known as the masked fin-foot (Heliopais personata). In order to protect these species, the Bangladesh Wildlife (Conservation and Security) Act of 2012 limits human activities in the sanctuaries to patrolling, research, and tourism.
Forest Department records show that very few wildlife crimes are currently being detected, the authors of the study note, with an average of only five incidents per year recorded for all three sanctuaries over the past five years.
Using their strategically placed camera traps, the researchers recorded a total of 914 unique human activity events over a collective total of 1,039 “trap nights.” Of those activities, 872 were illegal. Only 42 were legal activities related to patrolling or tourism.
“Law enforcement in the Sundarbans is sometimes hampered by the resources available for patrols, low numbers of staff, tides, boat engine problems and limited fuel,” Abu Naser Mohsin Hossain, Assistant Chief Forester of the Bangladesh Forest Department, who led the study, told Mongabay.
“Camera-traps extend the reach of the arm of the law by helping to monitor areas where ranger patrols can get to only infrequently, or in hotspots where poachers and illegal fishers tend to concentrate but stop their activities when they hear boats coming. The traps are operating 24/7 so all human activity is recorded. Photos recorded by the traps can help identify perpetrators, and know which boats have violated their permits.”
About 91 percent of camera trapped locations in the West Sanctuary had illegal human activities occur during the survey period, while 84 percent and 74 percent of locations in the South Sanctuary and East Sanctuary, respectively, also had illicit events occur. More than half of the infractions involved illegal fishing (54.3 percent), while crab collection (37.2 percent), firewood collection (5.5 percent), and nypa palm collection (3.1 percent) made up the remainder of the illegal activities that were photographed.
Not all photos yielded actionable intelligence, but when people or boats are able to be identified from the evidence, cases are able to be built for prosecution. Of the 605 photographs of illegal activities that were captured, paddle boats or motor boats were identifiable 37.4 percent of the time, while suspects were identifiable 25.1 percent of the time. Some 362 photographs (37.4 percent) could not be used to identify either an offending vehicle or human.
But because date and time stamps on identifiable photographs can provide actionable evidence for securing prosecutions for forestry or fishery crimes, these results suggest that camera traps are indeed effective means of reining in illegal human activities in remote protected areas, the authors of the study concluded.
Tommaso Savini, Associate Professor in the Conservation Ecology Program at King Mongkut’s University of Technology Thonburi in Thailand and the senior author of the study, told Mongabay: “Using state of the art statistical approaches the study showed how forest intrusions vary in space and time and highlighted how much illegal activity is actually taking place in the Sundarbans. This information is very important for informing management and guiding ranger patrols so they can better deal with illegal fishing and other human activities.”
- Hossain, A. N. M., Barlow, A., Barlow, C. G., Lynam, A. J., Chakma, S., & Savini, T. (2016). Assessing the efficacy of camera trapping as a tool for increasing detection rates of wildlife crime in tropical protected areas.Biological Conservation, 201, 314-319. doi:10.1016/j.biocon.2016.07.023