Horses are a romantic part of our history on this continent and literally helped us settle the region. Because there were no horses in North America at the time, Europeans brought them when they came to explore and settle the New World. Oglethorpe brought horses to Fort St. Andrews on Cumberland Island in the 1740s. The various plant communities on our barrier islands evolved under pressure from smaller herbivores such as deer and rabbits, and of course insects, but not large, herding ungulates.
Background
Horses were brought to the islands for utilitarian purposes and pleasure, and in the 1920s a train-car load of Western mustangs was released to run free on Cumberland Island. Because they are now a familiar animal, feral horses are automatically accepted by many as a “natural” component of the island fauna, however; they are just as unnatural here on the island as they would be in downtown Atlanta. If people were as familiar with the natural island ecosystems as they are with the city streets, the inappropriateness of horses would be obvious. Just as horses would compete with autos and people for space on a city street, they compete with native species on the island for space and food.
A lawsuit was brought against the National Park Service (2024) asking them to take action necessary to assure the overall well-being of the feral horses on Cumberland Island and to protect the natural and Wilderness resources of the island. The Court dismissed the complaint by saying that the NPS has taken no action at all regarding the horses, thus there was no final “Agency action” therefore nothing available for judicial review. Unfortunately, the Court held that most laws and plans governing the management of the National Seashore are unenforceable.
Impact on Island
As animals of open grasslands, horses naturally prefer and are adapted to open areas, of which there are few on Cumberland Island. They are lured to the open expanse of the salt marsh, lacking a closed tree canopy and with plenty of grass. There they wade in soft mud, sometimes nearly to their bellies, feeding on marsh grass. Their trampling has a devastating effect on the marsh and its fauna, with hooves churning the soft marsh community into soup. They regularly feed along the open beach where their grazing destabilizes the sand dunes. Because of their large size, horses inadvertently trample small native fauna, killing snakes, turtles, and ground-nesting birds.
Horses eat acorns as well as grass and forbs and thus compete with native wildlife for food. For a century, the native island fauna has had to sacrifice limited resources to feral horses.
It has been calculated that 150 horses deposit 1.65 million pounds of waste per year, which contributes to reduced island water quality, both fresh and salt. Organic matter in defecated effluent starves the water of oxygen, can cause excessive bacterial growth and fungal slimes, which can raise pH and kill sensitive plants and animals. Pathogens are also found in horse waste.
Impact on Horses
Feral horses living on Cumberland Island lead a very difficult life, especially the females. Most people who see horses on the island do not have a chance to observe the hardships they face as they eke out a living in inhospitable terrain, while causing considerable damage to other species and the environment.
Horses are not adapted to live in forests; they are native to open grasslands of the Great Plains of SE Europe and Asia. Vines and thick underbrush make manes and long tails a liability. They catch and hold an animal until it dies of dehydration or starvation. Nor are horses inherently familiar with the deep marsh mud, which sometimes traps and holds them until the tide comes in and drowns them. They have gotten caught between two trees and been unable to escape. Alligators steal their careless young, and broken legs and serious snake bites occur. Along with often inadequate food, horses must contend with biting flies, encephalitis-carrying mosquitoes, and thousands of ticks.
Females have the additional burden of having to eat for two or three from their first estrus as a yearling until they die. Conception may occur two weeks after giving birth, leaving them continually pregnant. No wonder we see so many gaunt females.
Horses are not adapted to live in forests.
Today
Most of the Florida barrier islands are developed and essentially all of Georgia’s are manipulated for special purposes. The area of Cumberland designated Wilderness in 1982 is the only area representative of a large island maritime forest with associated ecosystems having the potential and mandate to be managed to allow natural functioning of the systems. To function naturally and complete its natural succession to a climax forest, our maritime forest must be as free from outside influences as possible, which includes the impacts of feral animals
Conclusion
There is both a state Shoreline Protection Act and a Marshland Protection Act to protect these ecosystems from manipulation, including from human introduced livestock (horses), but the state looks the other way. In the past, the Park Service installed exclosures on the beach dunes and in the salt marsh to measure the impact of the horses, but are the data from those projects available?
In 2004, the National Park Service (NPS) Water Resources Division in Colorado sent a wetland scientist and a hydrologist to Cumberland Island who evaluated the adverse impacts from the feral horses on the island wetlands. Based on a literature review, park staff input, and field observations, K. Noon and M. Martin produced a Position Paper, concluding that “maintenance of the feral horse herd caused unacceptable impacts to the Park’s wetland resources, values, and purposes whose effects cannot be satisfactorily mitigated.” They recommended removal of the population from the island. A small number, they said, could be confined and maintained with health care and feeding. They pointed out that the same recommendations were provided by the Hillestad et.al. 1975 Report.
Speaking of water, the ocean water at Sea Camp beach, where most visitors swim, sometimes has bushels of horse manure along its edge. Is that water tested?
NPS Management Policies 2006 is quite clear on management of exotic species and horses/livestock are considered exotic species: “The Service will… manage recreational and administrative uses of livestock to prevent those uses from unacceptably impacting park resources. And, all exotic plant and animal species that are not maintained to meet an identified park purpose will be managed—up to and including eradication … if they interfere with natural processes and the perpetuation of natural features, native species or natural habitats.”
It should be clear that horses do not belong in Wilderness.
If you have concerns about the horses, the island, or NPS management please write: Superintendent, Cumberland Island National Seashore, P.O. Box 806, St. Marys, GA 31558; CUIS_Superintendent@nps.gov. And please send us a copy:
CIM, P.O. Box 7080, St. Marys, GA 31558; CIMuseumCumberlandIsland@gmail.com.