Dogs can detect trafficked wildlife hidden in shipping containers from tiny air samples

Wildlife trafficking is a global crisis impacting at least 4,000 species of plants and animals, including mammals, reptiles, birds, corals and rare plants.

A shocking case from 2025 involved the seizure of 3.7 tonnes of pangolin scales in Nigeria. These scales were believed to be sourced from more than 1,900 individual pangolins.

While this case was uncovered, many more remain undetected. These crimes aren’t just pushing species toward extinction, they’re also putting people at risk. Hunting, trafficking and handling wild animals creates opportunities for diseases to jump from animals to humans. Wildlife trafficking is therefore not just a conservation crisis, but a serious threat to public health.

In our recent paper published in Conservation Biology, we present a new method for tackling this global crime. It uses a tiny sample of air extracted from a shipping container – and the incredible power of a dogs’ nose.

Traffickers exploit shipping routes

People buy and sell a wide range of wild animals and their parts for many reasons, such as pangolin scales for traditional medicines, monkeys for exotic pets, or even porcupines for bushmeat.

Traffickers exploit global transport routes to move their products, with shipping containers in particular being ideal targets.

Containers carry up to 90% of the world’s cargo, meaning products can be easily concealed and blend into the high volume of container traffic moving through ports.

Despite this, on average only about 2% of containers are physically inspected due to resource limitations.

There are few wildlife specific detection tools, and wildlife crime is often considered a low priority. Combined, this means most trafficking slips through undetected.

Bringing the scent to the dog

To bridge this gap, we investigated air sampling as a way to screen containers for wildlife without opening them, damaging cargo, or disrupting port operations.

This work was part of a four-year project, undertaken in collaboration with the world’s third largest shipping company CMA CGM.

We designed a portable air extraction device that fits onto a standard container vent and draws air through a filter to collect a sample. The sample is then presented to a trained detection dog which can indicate whether the scent of specific wildlife products is present.

In our study, we concealed pelts from five big cat species – lion, tiger, leopard, snow leopard and cheetah – inside standard-sized shipping containers. The pelts were arranged to simulate smuggling scenarios, including being hidden inside cardboard boxes to increase concealment.

Our detection dog successfully detected the pelts with almost 98% accuracy when air was extracted from the shipping container. They did so even when the pelts were concealed, demonstrating that the scent can escape into the container airspace and be reliably captured.

Detection dogs are already widely used by customs and border agencies around the world, but their ability to screen sealed containers at scale is limited. Containers are often inaccessible, stacked high, or in environments that are unsafe for dogs.

Our approach brings the scent to the dog, allowing many more containers to be screened efficiently and safely.

While the study was conducted under controlled conditions, these early results are encouraging. Pairing detection dogs with air-sampling could dramatically improve the detection of illegally trafficked wildlife hidden inside shipping containers.

The air extraction device is low cost, portable and scalable, making it well suited for use in high-risk ports and border crossings worldwide. The method could also be readily adapted for detecting other forms of trafficking, such as drugs, increasing its appeal to border agencies.

Disrupting criminal networks

Further trials are planned to validate the effectiveness of this approach in operational port environments across a broader range of wildlife products.

We are also exploring machine-based detectors to analyse samples and support the future development of this project.

However, initial findings show the dogs still outperform these technologies, which currently remain our most effective approach.

Our goal is to give frontline agencies practical tools to fight wildlife trafficking.

Through applying science-based research in the field, we can bridge enforcement gaps and detect trafficked wildlife faster, allowing us to better protect threatened species and disrupt the criminal networks behind this devastating trade.