Delft Island (Neduntheevu) feral ponies: Dutch colonial origin and dry limestone ecology?

Delft Island (Neduntheevu) in the Palk Strait is home to a population of approximately 500 wild feral ponies, descendants of horses introduced by Portuguese and Dutch colonial administrators in the 17th century for regional trade. The island is flat and arid, composed of exposed Miocene limestone. Ponies survive on coarse Bermuda grass and fallen fruit from palmyrah palms (Borassus flabellifer), drinking from brackish limestone water depressions called "Devil's Wells." Across the island, local residents build intricate dry-stone boundary walls crafted entirely of stacked coral boulders fitted together without mortar.