Sable Island horse population
Sable Island is well-known for its population of wild horses. The wild horses are descendants of animals introduced to the island in the 1700s, and are considered by many to be iconic features of the island with natural and cultural heritage value. The current population is approximately 500 horses.
In 1961, the Sable Island horses were formally protected under the Sable Island Regulations of the Canada Shipping Act and since that time have persisted without human interference.
When Sable Island was established as a national park reserve in 2013, and Parks Canada assumed responsibility for management of the island, the horses were considered a naturalized species and part of the island ecosystem.
The definition of the horses as a wild population of a naturalized species – an animal in its present habitat for more than 50 years - is consistent with the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and International Union for Conservation of Nature (IUCN) definition of wildlife.
As a naturalized species, the horses are now protected under the Canada National Parks Act and the National Parks of Canada Wildlife Regulations. This means that they do not live and breed as domesticated animals, they do not depend on humans for survival and as a result the population is managed with minimal intervention. As with other wildlife in national parks, the Sable Island horses are protected from hunting, harm, and disturbance, they do not receive veterinary care and people are not allowed to touch, feed or otherwise interact with the horses. Parks Canada requires people to maintain a distance of at least 20 m from the horses.
During consultation at the time of park establishment, Parks Canada received a clear message that the public wanted a consistent and high level of federal protection for the horses.
The genetic structure of the horses on Sable Island is very different from any other breed or population of horses, reflecting forces of natural selection and genetic drift that have influenced the population for over 250 years. These horses have adapted remarkably well to their harsh environment.
Historically, the horse population has fluctuated between 150 and 250 individuals. Since their protection in 1961, the population has been slowly increasing, and in recent years has fluctuated between 450 and 550.
The horses generally live in small family bands, which include a dominant stallion and one or more mares and their juvenile offspring. Males often remain solitary or form groups with other males (without mares) or younger males.
The horses feed primarily on the abundant marram, or beach grass, that covers a third of the island’s surface, but supplement their food intake by eating various other plants, such as beach pea, sandwort, and even some algae that washes up on the beach.
On the western half of the island, horses drink from the freshwater ponds, but on the eastern half, there are no ponds, and horses access the groundwater by digging shallow wells in the sand.
The number of horse births and deaths varies from year to year, with an average of 76 foals born each year, usually in late spring, and 64 horse deaths per year or 12.4% of the population (data from last 10 years). Most mortality occurs in the late winter and early spring, when lower food availability, combined with wet, windy, and cold weather can pose challenges to the population, which is not uncommon for many wildlife species. Variables in weather conditions during the winter months can have a significant impact on both the birth and survival rates on the population from year to year.
Parks Canada collaborates with experts to research and monitor the horses and their ecological role on Sable Island as well as other animals and plants, and the data collected helps to inform priorities and guides conservation.
Parks Canada does not control or actively manage the horse population. As there is no immediate risk to the population, Parks Canada does not plan to provide assistance to the wild horses, and there are no plans to remove the horses from Sable Island.
If new data suggests that the horses are at risk, Parks Canada would then evaluate options to ensure their protection.
Parks Canada will continue to work closely with researchers and partners to monitor the health of the wild horse population as well as other aspects of the ecology of Sable Island National Park Reserve as part of an ongoing effort to maintain the ecological integrity of the island.