Trained African giant pouched rats may help detect trafficked rhino horn and ivory products

A recent study published in the journal Frontiers in Conservation Science reveals that African giant pouched rats could play a significant role in combating illegal wildlife trafficking. Researchers led by Dr. Isabelle Szott from the Okeanos Foundation and Dr. Kate Webb, an assistant professor at Duke University, have successfully trained these rats to detect the scents of pangolin scales, elephant ivory, rhino horn, and African blackwood, all of which are commonly trafficked and threaten species with extinction.

The study involved training eight out of eleven African giant pouched rats to identify these wildlife products among 146 non-target substances, including cardboard, electric cables, and synthetic wigs. The rats, some named after notable conservationists such as Attenborough, Fossey, and Irwin, demonstrated remarkable ability to remember smells even after long periods without exposure. "Our study shows that we can train African giant pouched rats to detect illegally trafficked wildlife, even when it has been concealed among other substances," Dr. Szott explained.

The training was conducted at the headquarters of APOPO, a Belgian non-profit organization based in Tanzania with 25 years of experience offering low-cost humanitarian solutions. These rats have previously been trained by APOPO to detect explosives and the tuberculosis-causing pathogen in countries like Cambodia, Angola, and Zimbabwe. "APOPO's rats are cost-efficient scent detection tools," Dr. Szott stated. "They can easily access tight spaces like cargo in packed shipping containers or be lifted up high to screen the ventilation systems of sealed containers."

The rats underwent several stages of training. Initially, they learned to hold their noses for several seconds in a hole where the target scent was placed, a behavior known as the 'nose poke.' When they performed this correctly, they were rewarded with flavored rodent pellets. During the discrimination stage, the rats learned to signal only the odors of the wildlife targets while ignoring non-target substances. "The rats also continued to detect the wildlife targets after not encountering that species for a long period," Dr. Webb noted.

One of the key advantages of using African giant pouched rats is their cost-effectiveness compared to traditional detection methods. Training each rat costs between $7,000 and $8,000, significantly less than the $20,000 to $30,000 required to train sniffer dogs. Additionally, these rats are agile and can navigate tight spaces, making them suitable for inspecting cargo containers and ventilation systems at ports where illegal wildlife trafficking often occurs.

The researchers are now developing ways for the rats to communicate their findings in real-world settings. The next step involves fitting the rats with custom-made vests equipped with a small rubber ball containing a micro-switch. When the rats detect a target scent, they can pull the ball to emit a beeping sound, alerting handlers to the presence of smuggled goods. "We need the rats to alert us when they find something, because if we think of a port, we won't be able to see them among all the packages," Dr. Szott explained.

Operational trials have already been conducted at the Dar es Salaam seaport in Tanzania. "We have already done tests at the port of Dar es Salaam, but the results of that work have not yet been published," Dr. Szott stated. Dr. Webb added, "This was a huge next stage to ensure that rats can operate in these noisy, smelly, and busy environments."

Illegal wildlife trafficking is a significant global issue, with the trade in illegal wildlife products worth up to $20 billion a year, according to global police organization Interpol. Species such as elephants, rhinoceroses, pangolins, and the African blackwood tree are listed as threatened or at high risk of extinction and are illegally trafficked. Wildlife smuggling not only threatens biodiversity but is often conducted by individuals engaged in other illegal activities, including human, drug, and arms trafficking. "Therefore, deploying rats to combat wildlife trafficking may assist with the global fight against networks that exploit humans and nature," Dr. Webb said.

While the rats have shown promise, the researchers acknowledge limitations. The study was conducted in a controlled environment, which does not fully reflect the settings in which wildlife is commonly trafficked or screened by scent-detection animals. "To deploy rats for this task, new methods need to be developed," the researchers noted.

Experts in the field have expressed optimism about the potential of this approach. "Fighting wildlife crime is expensive and budgets are always tight, so search rats are likely to be a practical solution for law enforcement agencies," said Tim Redford, training coordinator at the Freeland Foundation, an anti-wildlife trafficking non-governmental group. He emphasized that the creatures must be "cared for ethically and rewarded for their work."

The researchers are hopeful that their work will lead to broader adoption of trained rats in combating wildlife trafficking. "We don't envision the rats to replace existing solutions, but rather complement them," Dr. Webb stated. "By adding a specialized tool such as rats, this can free up time for other solutions to focus on the specific areas they are best suited to."

With further development and field testing, African giant pouched rats could become an innovative and cost-effective tool in the global effort to combat illegal wildlife trafficking, helping to protect endangered species and disrupt criminal networks involved in this illicit trade.

Sources: EL PAÍS, Science News, ZEIT ONLINE, The National, Popular Science, Phys.org, Australian Broadcasting Corporation, Financial Times News

This article was written in collaboration with generative AI company Alchemiq