Stopping wildlife trafficking in its tracks

The illegal wildlife trade is a serious conservation threat on the African continent. Advances in isotope studies allow this technology to be used widely to counter animal trafficking. It can help trace an animal’s origins, map poaching hotspots, uncover wildlife trading fraud, or build a forensic timeline.

Written by: Leonie Joubert
Photographs by: Sam Reinders

Learning to think like Sherlock Holmes: participants in a training programme at the Wildlife Forensic Academy outside of Cape Town study a staged crime scene to learn how to gather evidence and find clues to will explain how an animal was killed.

Forensic science is widely used to investigate wildlife-related crimes, and typically uses biological, physical, and digital evidence to build a case in illicit activities such as poaching, trafficking, and the killing or illegal trading of protected species.

The preserved rhino at the staged crime scenes at the Wildlife Forensic Academy had a bullet wound to the chest, and both horns missing. The keratin in a horn sample from a slain animal like this could hold the secret to whether the animal was a wild-roaming one, or raised in captivity, and what geographic region it came from.

Trainee forensics investigators examine a dead baboon at the Wildlife Forensic Academy, to determine how the animal might have died.

By studying the carbon isotopes in an animal sample, such as in an elephant tusk, law enforcement can establish its age, for instance to tell if the tusk was taken before ivory poaching was made illegal, or after. 

It was the knife wound in the lion’s chest that first caught Kardelen Karamahmutoğlu’s attention. It was obvious that this is what had killed the animal. But how did anyone get close enough to such a dangerous predator to inflict a lethal blow like this? Maybe the animal had been poisoned? Maybe darted with a tranquilliser?

She never got to answer this question, but that wasn’t necessarily the end-goal. The purpose of this exercise was to get a team of trainee sleuths to walk through the steps of a forensic investigation in the case of wildlife trafficking crime scene.

Karamahmutoğlu’s team of investigators included environmental scientists, wildlife rangers, people from the South African police force, and even some from the US’s department of homeland security. They were participating on a short training programme offered by the Wildlife Forensic Academy in August 2023, at a site on a private reserve about an hour’s drive from Cape Town.

‘We started by scanning the ground for footprints,’ the forensics science master’s student says, explaining how her group pored over the staged crime, methodically approaching the taxidermied lion in search of more clues as to who might have committed this crime, and how. 

Other students were taking the same approach as they investigated the scenes of a giraffe, killed by a snare, and a rhino with a bullet wound to its shoulder and its horns missing.

‘I had done my bachelor’s degree in biology, and I’d always been interested in forensic biology,’ explains the South African-Turkish student, who at the time was a year into a master’s at the Department of Forensic Science at Üsküdar University in Turkey.

‘While I was more drawn to animals and wildlife, I discovered I wanted to pursue a path combining wildlife and forensic science.’

It wasn’t until she attended the course at the academy that she learned of the potential of using stable isotope analysis as part of an investigative process in forensics and how it is a growing technology being used extensively round the world to counter wildlife trafficking.

Undergraduate studies had given her a teaser for isotope science, but now her master’s programme required that she design a novel research project for her thesis, and this was where she joined the dots.

‘There are very few students doing research in the area of isotopes and wildlife trafficking,’ she explains.

Older technologies can be useful for determining the nature of animal tissue sampled from poached specimens, but in some cases, it might not show any unique chemical or physical traits. Zooming in on its isotope makeup can reveal valuable pieces of information: carbon dating can help work out the age of the animal or narrow down a likely location where it might have roamed before being poached, or unique characteristics of its diet.

In order to learn these techniques and contribute to the wider body of knowledge, Karamahmutoğlu decided to map the isotope profiles of a number of grazing animals in the Buffelsfontein Game and Nature Reserve, the 1,600 hectare private reserve where the Wildlife Forensic Academy is located in South Africa. By determining their isotopic makeup, this could be compared with the isotopes of similar species found in other geographic locations around the country and create a more complete map of the region’s isotope values.

Starting in December 2023, Karamahmutoğlu sampled the tissue from bone, teeth, feather, dung and keratin from a range of grazing and browsing animals and some birds that had either died naturally on the reserve, or been hunted. These came from rhinos, zebra, kudu, springbok, two species of wildebeest, giraffe, eland, two tortoise species and three birds. She then took the samples to the Stable Light Isotope lab at the University of Cape Town (UCT) Department of Archaeology, where she spent four months to doing isotope ratio mass spectrometry analysis.

Isotopes: another layer of knowledge in the fight against wildlife trafficking

When wild animals forage, they pick up the unique isotopic fingerprints of a region. Elements such as nitrogen, hydrogen, oxygen, carbon, sulphur and strontium that are present in soil, plants and water have unique markers that are shaped by environmental factors such as the geology, climate or water cycle of that specific location. As animals drink the water or forage, they pick up these isotopic signatures, which get stored in tissues such as keratin in horn, hooves, hair or beaks, and in teeth, bones, tusks and blood.

Studying these isotopes can reveal many things about the history of an animal, and in the case of wildlife trafficking is already used to trace an animal's origins, or how trafficked animals or animal products are moved along the illicit supply chain. For instance, being able to identify which location and even which population a poached elephant or rhino came from can help authorities pinpoint poaching hotspots and tailor conservation and anti-poaching efforts for unique contexts.

Isotopic information can allow law enforcement to distinguish between wild or captive-raised animals. It can also track forensic timelines, for instance by using carbon dating to tell if an elephant tusk was taken before the international ban on ivory trading, or after.

Sifting through the noise of messy data

Karamahmutoğlu hit a snag, though. There was an unexpected signal in the carbon isotope readings from many of her samples.

The vegetation at the Buffelsfontein reserve is a tough, heat- and fire-adapted community of plants that has evolved in this uniquely winter rainfall region of the African continent, known as fynbos from the Dutch description, literally meaning ‘fine bush’.

Most of the plants in fynbos use the C₃ photosynthetic pathway for metabolising carbon, rather than the C₄ pathway. These two pathways have distinctive carbon isotope ratios.

Since the vegetation at the reserve is fynbos, Karamahmutoğlu was expecting to find mostly C₃ isotope values in her samples.

Only, there were also plenty of C₄ readings in the analysis, which showed that the animals had eaten food containing the carbon compound found in plants such as lucerne, wheat, or soybeans, which don’t grow on the reserve. This was confounding at first, and she thought it might compromise her objective of creating an isotopic map of the natural vegetation here on the reserve, and one that could be compared with other geographic regions of the country.

But as is the way of science, she was able to trouble-shoot the situation: she quickly realised what was causing this noisy signal, and how to work around it. Reserve managers regularly give the larger animals supplementary fodder, such as lucerne, which would explain the C₄ readings in amongst the carbon readings that show the animals were also eating natural veld.

‘Initially, the presence of both C₃ and C₄ markers in some species did pose a challenge for the study, but it didn’t make the data useless,’ explains Karamahmutoğlu, after wrapping up her thesis.

‘It just required careful interpretation. After analysing the isotope ratios across multiple species, we found that despite the supplementary feed, the ratios within the same species were still consistent enough to compare with data from other locations.’

This means the data was useful in understanding geographic differences.

Isotope analysis is easier to use than DNA

Traditional forensics use methods such as fingerprinting, time of death, mode of death such as poison detection, firearm ballistics or physical traits for species identification such as body markings or beak shape.

This can help identify if a specimen is a protected species and subject to poaching or trading laws.

Forensic methods for addressing wildlife trafficking also extend to linking suspects with crimes, such as fingerprint matches, or ballistics traces linking a specific firearm with a crime. If a suspect has left their own DNA on a firearm or a suspected trafficked species, this can also be a way to link that person with the crime.

DNA as a forensic tool to trace the possible location and source population of a poached specimen isn’t a likely or readily available method in this context, though.

‘You need to have maps of a species’ existing DNA in populations and be able to match the specimen sample to these maps,’ explains BIOGRIP Director, Dr Roger Diamond. ‘You are looking for a tiny fraction of the total genome, the part that distinguishes populations of the same species.’

Isotope analysis is easier to use than DNA, in this context.

Isotopic analysis of elements found in an animal’s tissue can add another layer of forensic evidence, although the results are not always as easy to interpret as fingerprinting or cause of death.