Horse
Depending on breed, management and environment, the modern domestic horse has a life expectancy of 25 to 30 years. Uncommonly, a few animals live into their 40s and, occasionally, beyond. The oldest verifiable record was "Old Billy", a 19th-century horse that lived to the age of 62. In modern times, Sugar Puff, who had been listed in "Guinness World Records" as the world's oldest living pony, died in 2007 at age 56.
Banker horse
The National Park Service (NPS) is concerned about the impact of Bankers on the environmental health of North Carolina's barrier islands. Initially, the NPS believed that the non-native Bankers would completely consume the "Spartina alterniflora" grasses and the maritime forests, as both were thought to be essential to their survival. Research in 1987 provided information on the horses' diet that suggested otherwise. Half of their diet consisted of "Spartina", while only 4% of their nutrients came from the maritime forest. The study concluded that sufficient nutrients were replenished with each ocean tide to prevent a decline in vegetative growth from overgrazing. A 2004 study declared that the greatest impact on plant life was not from grazing but from the damage plants sustained when trampled by the horses' hooves. Bankers pose a threat to ground-nesting animals such as sea turtles and shorebirds. Feral horses interrupt nesting activities and can crush the young.