Saint Mary's University students collect data from over 700 horse skulls from Sable Island

Kate Chadwick and Richard Orton have spent countless hours collecting and recording data from over 700 horse skulls collected from Sable Island.

“It’s really about getting a comprehensive view of what’s going on with these skulls physically,” said Chadwick.

The PhD students at Saint Mary’s University in Halifax are helping to create a database for future research about the species.

The almost mythical Sable Island horses have bewildered generations of scientists eager to learn more about their existence on the remote island off the coast of Nova Scotia.

“The history of the Sable Island horses seems to be somewhat contentious,” said Orton. “We do know that they have been isolated for at least 50 years, which is enough time for approximately 10 generations. If there’s strong natural selection acting on these horses, that could be enough for morphological changes over time.”

The students were tasked with cataloguing the collection, which included capturing over 6,000 images and 13,000 measurements of the skulls.

Orton says by analyzing and comparing the data, it may help unearth some important discoveries about the species’ biology.

“One of the comparisons we are trying to make is between male and females,” said Orton. “In other papers that have done similar research in purebred populations of horses, they don’t find differences in the genders but this is an island population and sometimes unique adaptations occur on islands because they are isolated."

Some unusual abnormalities in the skulls include what’s believed to be a root canal abscess in the lower jaw, as well as a cheek bone abscess.

“We even found a small bird in one of the skulls that had obviously created a nest there,” Chadwick said. “It shows that even though the horses are dead, they are intimately linked with the environment that they come from.”

The students were also given thousands of bagged teeth, which had to be paired with the correct skulls.

Chadwick says the teeth help provide insight into the approximate age of the horses.

“The teeth protrude from their mouth, so when they are young it starts at 180 degrees,” Chadwick said. “Towards the end of their life, the angle between their teeth is about 90 degrees.”

The research project is a collaboration between the Sable Island Institute, SMUworks and The Frasier Lab.

All of the horse skulls were collected over the last 30 years by Zoe Lucas, the president of the Sable Island Institute.

In November, an outreach event was held at the university to give members of the public a chance to see the specimens in-person and ask questions about the project.

In addition to their research work with the Sable Island horses, Chadwick and Orton will be addressing conservation concerns of the North Atlantic Right Whale.