Could dogs be an archaeologist’s best friend?

Archaeologists are constantly searching for the forgotten secrets of our past. Their next asset in uncovering these mysteries could come from an
unlikely source: dogs. With a nose that is capable of smelling up to a thousand times better than people, archaeology dogs could provide a non-invasive way of identifying animal and human remains at a site. Significantly, this reduces the risk of over-exposure for sites of archaeological significance, leaving the remains untouched when necessary.

It is well known that dogs help the police in drug detection, but what you may not know is that dogs can also assist in the detection of human remains. Cadaver dogs or Human Remains Detection dogs have helped police close countless cold cases and provide closure to the families of victims. Dogs have been detecting human remains for over two hundred years. That same skill is what makes them potentially useful to archaeologists, too.

Specially trained Historic Human Remains Detection (HHRD) dogs could provide a way to detect a person’s final resting place without disturbing the physical remains. This is particularly important in cases where religious, cultural or ethical beliefs make it impossible to actually excavate the remains.

In 2007, in San Diego County, California, for example, a construction project was infringing on a Native American burial site. With the consent of the indigenous community, the site was searched in 2007 and 2011 by six different dogs. Fourteen potential burial sites were identified. As a result, the indigenous community were able to alert the construction company to the burial sites, so that hopefully they would remain undisturbed. When construction in 2012 accidentally disturbed one of those potential burial sites, it was indeed found to have contained a burial.

Dogs are usually selected from herding and working breeds, and undergo many years of training to become HHRD dogs. They are trained using soil samples of different ages from different historic sites. Even after they have completed their basic training, they have to attend regular training sessions and take tests to make sure they are working at maximum efficacy. A well-trained HHRD dog can even detect a burial site if the remains are no longer present (due to complete decomposition or removal of the remains) or if the remains are cremated, because the scent of decomposition is incorporated into the soil.

Despite HHRD dogs yielding positive results, they are not perfect. Environmental factors such as vegetation, temperature and weather conditions can all affect whether the scent of human remains can reach a dog’s nose. Dogs are trained to alert their handler with a cue, such as barking or sitting, where the scent is strongest. But the scent could be strongest metres away from the burial. The Institute of Canine Forensics approximates that their HHRD dogs give alerts for a twentieth-century burial within four metres of the grave. Therefore, it is recommended that multiple dogs undertake multiple searches of the site so that the location of the human remains can most accurately be identified.

But archaeology dogs aren’t solely used for the detection of human remains. Anthropologist Lauri Travis and student Hannah Decker at Carroll College in Montana have trained Border Collie and Australian Shepherd mix Dax to seek out animal remains. Speaking to journalist Jill Neimark in 2020, Lauri Travis explained that her investigation aimed to “find out what Native peoples ate during two important droughts, one 8,00 years ago and one 2,000 years ago.” Decker gradually trained Dax using powdered animal bone, for a stronger scent profile, and then progressed to a whole animal bone. Recently Dax has been able to locate a 5000-year-old bone buried twelve
inches deep.

What a detection dog alerts to all depends on training. In a report for Idaho television station KTVB, Paula Cudd says that HRD dogs like her dog Ziva, would be trained with “distractions” like food or dead animals. “The dog must ignore all but the target odour,” Paula explains. Swedish archaeologist Sophie Valluv’s published masters thesis was on experiments with her trained German Shepherd, Fabel. Valluv recalled to Jill Neimark that she “wanted to see if he could distinguish between animal and human bones.” In a sterile indoor lab, Valluv conducted 120 different searches on samples which may have contained human remains. Valluv did not know which samples contained the human remains, so that she could not give Fabel signals to favour specific samples unconsciously. Valluv and her team concluded that Fabel could determine which samples contained human remains with 94.2% accuracy. This is important as it allows archaeologists to have faith that their dog will be able to assist them in answering specific research questions.

Although research is limited at the time of writing, the general consensus is that archaeology dogs should be used alongside other non-invasive techniques such as Ground Penetrating Radar (GPR). GPR creates a 3D image of features below ground by sending an electromagnetic pulse through the ground at regular intervals. These pulses bounce off features and are detected by the antenna. The combination of GPR and HHRD dogs allows archaeologists to deduce the area of the possible burial locations and focus in on features that they may want to investigate.

Working archaeology dogs are not yet a common sight on digs. But as more research is undertaken, archaeology dogs could become valuable assistants to the archaeologists’ exploration of our history.