Horses on Cumberland Island have a relatively short life expectancy, due to pest infestations, disease and their rugged environment.

In 2000 a behavioral study found that instability marks the bands, with large numbers of co-dominant stallions, early dispersal of juveniles, and frequent band-changing among mares.

The National Park Service has no current management plan for the horses, and their one effort to create one was blocked by Jack Kingston, a Georgia member of the US House of Representatives.

[1][2] However, it is believed that these first horses more than likely did not survive due to the lack of visits made by the Spanish and the local Native Americans on the island finding them of little practical use.

[3] The life span of horses on Cumberland Island is approximately half that of their ancestors, due to infestations of parasites and disease.

They also suffer from digestive issues linked to the ingestion of a great amount of sand, which causes intestinal blockages and abdominal distension.

The researchers attributed this to a lack of territory, with bands frequently inhabiting overlapping areas, along with a high number of bachelor stallions (those without mares).

[4] An initial study published in 1988 by a researcher from Oak Ridge National Laboratory demonstrated the then-current population of 180 horses was over-grazing the island.

The researchers noted that they were looking at herd size solely as it related to genetic variation, and did not take environmental damage into consideration.

After compiling information, they released a draft environmental assessment in early 1996 and began taking public comment on a potential management plan.

[10] However, before a plan could be implemented, US Representative Jack Kingston included a provision in a federal appropriations bill that prevented any management of the horses.

[1] The study published in 2000 recommended a management strategy that reduced herd populations to environmentally-recommended sizes through a combination of off-island adoption to private owners and contraceptives.

[4] In 2009, a study was conducted by the Warnell School of Forestry and Natural Resources at the University of Georgia to determine public opinion on the management of the feral livestock (horses and pigs) on the island.

The majority of visitors tended to prefer non-lethal methods of managing the population, as opposed to non-management or complete eradication.