The island's fauna is mainly comprised of animals familiar to Westerners: semi-wild horses roaming the hills, rabbits, and herds of cattle. Before the arrival of the Europeans no mammals existed, the only native fauna was seabirds such as, pelicans, terns, sea swallows, frigate birds and albatross. Seagulls, such as the San Felix Gull and San Ambrosio Gull scavenge the island too. Two reptiles, Lepidodactylus lugubris and Ablepharus boutoui poecilopleurus, also live on the island. Below the waterline, scuba divers will discover 160 endemic species of fish. For land lovers a walk along the craggy shoreline will reveal small snails whose shells the locals use to make necklaces. Estimates put the total number of plant species on the island at 150, with 45 considered indigenous, including three endemic species of grass. The exact nature of the island flora is uncertain as studies are continuing and many authorities disagree on the identification and classification of some of the plants. Amazingly recent paleobotanical studies of fossils indicate that prior to the arrival of the first Polynesians, the island had a much greater array of trees, shrubs, ferns, and grasses. The long-extinct Jubaea palm is thought to have been the principal wood used to transport the immense stone statues.