An important part of the Warhorse Project is determining where the horses were born in order to reconstruct the movement of the horses throughout their lives. Key to this is stable isotope analysis, including strontium. In this blog post, we will introduce you to how the Warhorse team samples medieval horse teeth for strontium isotope analysis.

Strontium isotopes (⁸⁷Sr/⁸⁶Sr) can provide the location of birth in animals, including people and horses, as well as their mobility in life. As tooth enamel is formed during childhood when animals eat or drink, it records this chemical isotope from the local bedrock. This bedrock varies throughout the UK, giving us various ranges of ⁸⁷Sr/⁸⁶Sr, as seen below.

We take samples from horse teeth to compare to these ranges to determine where they were born within, or even outside of, the UK. The process involves the following steps, shown here with the Elverton Street horses from the Museum of London Archaeology (MOLA).

Step 1: Choose teeth from different individuals and different archaeological contexts throughout a particular archaeological site. The goal is to get an understanding of the place of birth and life histories of as many horses as possible.

Step 2: Take photographs and measurements to record the teeth before sampling, as it is a destructive method. Each sampled tooth is assigned an ID number. This is a lower (mandibular) 3^rd molar from a horse that is approximately 9-10 years old, ID ELV2.

Step 2: Cut strips of enamel from the horse molars. We use the 2^nd and 3^rd molars for this. Dremels with thin, precision drill bits are used for this process.

Step 3: Photograph again to make sure we know which strips belong to which tooth (and which individual and context).

Step 4: Label, draw, and measure the tooth and the resultant strips.

Steps 5 & 6: Glue strips of enamel to paper in a ring shape, and draw a map of which teeth are where in the ring. The map is critical to be able to match the strontium isotope ratio to the particular horse.

Step 7: Fill the ring with the strips of teeth. The teeth have to fit inside the ring in order to fit in the mass spectrometer which measures the strontium.

Step 8: Pour a two-part epoxy resin over the strips, and leave to harden overnight.

Step 9: End up with a hardened resin disc with the strips of teeth in it. We have teeth from 17 different horses in two discs!

Step 10: Photograph the disc again to produce a final map.

After the teeth are sampled and prepared, Dr Alex Pryor, archaeologist and University of Exeter isotope specialist, will be undertaking the analysis using Laser Ablation Multi-Collector Inductively Coupled Plasma Mass Spectrometry (LA-MC-ICPMS) located in the Plasma Mass Spectrometer Laboratory, National Oceanography Centre, University of Southampton, UK. Once he has finished this analysis, Dr Pryor will help the Warhorse team interpret the results to gain an understanding of where the horses in the project were born and may have traveled during their lives.

Reference

Evans, J. A., Montgomery, J., Wildman, G. & Boulton, N. 2010. Spatial variations in biosphere ⁸⁷Sr/⁸⁶Sr in Britain. Journal of Geological Society, London 167:1–4.

 

 

By Camille Mai Lan Vo Van Qui

Each year in October, the free-roaming ponies on Dartmoor are rounded up by the farmers to whom they belong, and the foals born that year are sold at auction in the village of Chagford. This event is interesting from the standpoint of equestrian history. Those ponies are called ‘Dartmoor Hill’, meaning that they are born on the moor, and must not be confused with the Dartmoor breed. Dartmoor Hill ponies are a mix of many breeds of horses, introduced to Dartmoor over the centuries, including Shetlands used for mining in the 19^th century.

Keeping horses in semi-managed conditions is a traditional way of equine husbandry. In the Middle Ages, horses were already kept on Dartmoor in that manner.[1] References to this way of managing equids are found in Jordanus Rufus’s De medicina equorum (c. 1250), one of the foundational texts for equine medicine and husbandry in medieval Western Europe: he advises that foals should be born in the mountains and left to roam freely for the first two or three years of their life because, according to him, grass and freedom are what is best for their health.

The colts are then rounded up to be taken back to the studs. There, they are tamed and broken in. Rufus gives some advice on how to capture the colts (describing, for instance, the material of the rope used to lasso them), but nothing is said about the handling of the horses or the number of people involved. This silence is no doubt due to the fact that the rounding-up and sorting out of the horses was so common and so well-known at the time that there was no point in mentioning it. Rufus was addressing himself to knowledgeable horsemen, so he only wrote down techniques and advice that were unusual at the time or the results of his own experimentations. The handling of wild[2] animals was not part of that.

A traditional event with possible medieval roots, such as the Chagford Drift sale, can provide interesting insights into the practicalities of rounding up and sorting out the horses. As a historian, it is easy to focus exclusively on textual sources. Yet, in the case of human/animal relationships, many aspects are experienced and lived and are not (or cannot) be put in writing. Therefore, when attempting to understand the relationship between humans and horses in history, contact with and observation of the animals can fill in some of the gaps in the written sources.

 

During the sale, the herding of the horses was done through a succession of corrals, with minimal physical contact between the humans and animals. The horses’ instincts as herd animals appeared to be used as they were moved as groups. When humans intervened, body language was important. When the horses were touched, it was on specific areas such as the rump. Short, loud vocal cues were used to encourage the horses. Some of the handlers were brusquer, handing out small punches on the rumps of reluctant horses, while others hardly touched the animals.

Interestingly, the handling of the horse appeared to be mostly male dominated, perhaps due to the very traditional aspect of the sale, and even though women were in charge of the organisational aspect. Children, mostly boys, also participated in the handling, hinting at the generational transmission of those techniques, probably through a process of observation and mimesis. It echoes what is hinted at in Rufus’s method: the parts on which he is silent imply that they were already transmitted, either orally or non-verbally through the process of observation. As such, they did not need to be written down. Even today, no instruction manual on how to handle wild ponies exist; it is knowledge that is actively used and passed on to the next generation and it will disappear once this chain is broken.

[1] See, for instance, Charles Gladitz, Horse Breeding in the Medieval World (Dublin: Four Courts Press, 1997).

[2] Wild here refers to the horses’ experience with human interaction. Despite being mostly left to their own devices, the ponies on Dartmoor are domesticated animals and not, in fact, wild.