African giant in your pocket rats (Cricetomys gambianus) could be the next line of defense against illegal wildlife trade. A team of researchers trained these three-pound rats to capture the scent of elephant ivoryrhino horn, pangolin scales and a small tree called African blackwood. All of these animals and plants are listed as threatened or at high risk of extinction and are subject to illegal trafficking. The results are detailed in a proof-of-principle study published October 30 in the journal Frontiers in conservation science.

“Our study shows that we can train African giant rats to detect illegally trafficked wildlife, even when they have been concealed among other substances,” Isabelle Szott, co-author of the study. study and behavior specialist from the Okeanos Foundation. said in a statement.

sniff things

Previously, giant African rats were trained to detect explosives and even the pathogen causing tuberculosis. This new study aimed at testing their ability to detect wildlife odors was carried out at APOPO. The Tanzania-based nonprofit aims to protect both people and animals through trained rats and other scent-detecting animals.

He understood 11 rats–Kirsty, Marty, Attenborough, Irwin, Betty, Teddy, Ivory, Ebony, Desmond, Thoreau and Fossey. All have undergone several stages of smell training. During the training on indications, they learned to hold your nose for several seconds inside a hole where the target scent was placed. If the rat correctly performed what the team called a “nose poke,” it was rewarded with flavored rodent pellets.

(Related: Rats can have imagination.)

Then the rats were introduced to certain non-target odors. This included coffee beanselectrical cables and washing powder. Wildlife traffickers often use these items to mask the scent of wildlife.

“During the discrimination phase, rats learn to report only the odors of wild targets, while ignoring non-targets,” Szott said.

Rats were also trained to remember smells. At the end of this training, they were reintroduced to scents that they had not encountered for five and eight months. Even with such a long period of non-exposure, they showed high retention scores. Their cognitive retention performance is potentially as strong as a the dog.

At the end of the training, eight rats were able to identify four commonly smuggled wildlife species from 146 non-target substances.

“Existing screening tools are expensive and time-consuming, and there is an urgent need to increase screening of goods,” Szott said. “APOPO rats are cost-effective odor detection tools. They can easily access tight spaces like goods in packed shipping containers or be lifted high to filter sealed container ventilation systems.

Bringing the Rats to Work

According to the teama good next step would be to find ways for rats to work in ports where smuggled wildlife is being trafficked. These include the ports of Mombasa, Kenya, as well as Dar es Salaam and Zanzibar in Tanzania, according to data from the United Nations Office on Drugs and Crime.

To do this, the rats would be equipped with tailor-made vests. They can use their front paws to put a small ball attached to the chest of the vest, which beeps. This way, trained rats will be able to inform their owners when they detect a target.

With their front paws, they can shoot a small ball attached to the chest of their vest, which emits a beep. This way, rats will be able to alert their owners when they detect a target.

“The vests are a great example of developing hardware that could be useful in different settings and tasks, including in a shipping port to detect wildlife smuggling,” Kate Webb, co-author of the study and neuroscientist at Duke University. said in a statement.

(Related: How science came to rely on the humble laboratory rat.)

Although the rats in the study were successful in identifying odors related to wildlife trafficking, there are still some limitations. The study was conducted in a controlled environment, so it does not reflect real-world settings where wildlife is typically trafficked or scouted by scent-detecting animals. In order to deploy these rats, new methods must be developed, according to the team.

“Wildlife trafficking is often conducted by individuals engaged in other illegal activities, including human, drug and weapons trafficking,” Webb said. “Therefore, deploying rats to combat wildlife trafficking could contribute to the global fight against networks that exploit humans and nature. »