Bora Bora, a volcanic island in the South Pacific, originated from an extinct volcano, whose central peaks, like Mount Otemanu, dominate the landscape. The island is encircled by a deep, turquoise lagoon, which is separated from the open ocean by a protective barrier reef and a chain of small, sandy islets known as motus. This unique geological structure has created two distinct, yet interconnected, biological environments: the terrestrial slopes of the main island and the expansive, sheltered marine habitat. The fauna that thrives here is highly specialized, having evolved within the constraints of an oceanic island’s natural isolation.
The Vibrant Life of the Lagoon and Reef
The sheltered lagoon and its surrounding coral reef are the heart of Bora Bora’s animal life, hosting a spectacular diversity of marine species. Visibility in the clear, warm waters often extends up to 30 meters, allowing for easy observation of the complex ecosystem. The coral reefs themselves, made up of species like brain coral and delicate branching varieties, form the foundational habitat for countless organisms.
Sharks are a prominent feature of the outer reef and lagoon, with Blacktip Reef Sharks and Lemon Sharks being the most commonly sighted. These species are generally non-aggressive towards humans, often observed swimming along the reef drop-offs. Their presence is an indication of a healthy ecosystem, as they regulate the populations of smaller fish species.
The lagoon floor is frequently cruised by large rays, most notably Manta Rays and various species of Stingrays. Manta Rays filter-feed on plankton, while Stingrays, including Leopard and Gray Rays, often forage in the sandy shallows. These cartilaginous fish are easily spotted during tours, often gathering in specific feeding areas.
Tropical fish inhabit the coral gardens and passes, including Parrotfish, Angelfish, and Butterflyfish. Clownfish find sanctuary within the tentacles of sea anemones, and Moray Eels peer out from crevices in the coral structure. The critically endangered Green Sea Turtle and the Hawksbill Sea Turtle are known to frequent the reefs for feeding and resting, benefiting from the protected status of French Polynesian waters.
Birds of the Sky and Shoreline
While the marine environment is dominant, the air and shoreline of Bora Bora also support an avian population. Seabirds are particularly common, taking advantage of the rich fishing grounds offshore and the secure nesting sites on the uninhabited motus. White Terns are frequently seen gliding effortlessly over the water and nesting in trees.
Other notable pelagic species include the Brown Noddies and the Great Frigatebirds. Frigatebirds rarely land on the water, instead soaring for hours and often engaging in kleptoparasitism, forcing other birds to drop their catch. The terrestrial areas of the main island host smaller birds, including the Pacific Swallow and the introduced Common Myna.
The island’s isolation means there is an absence of large, native predatory birds. However, introduced species, such as the Zebra Dove and the Common Myna, affect the avian community. These introduced birds often compete with native species for food and nesting sites.
Land Dwellers and Introduced Species
The terrestrial environment of Bora Bora supports a less conspicuous set of animals. Native land mammals are virtually non-existent, a common trait of remote oceanic islands. The animals found on land primarily consist of small reptiles, arthropods, and introduced mammals.
Small reptiles like Geckos and Skinks are common sights, often seen scuttling across walls or sunning themselves on rocks. Geckos are nocturnal hunters of insects, playing a role in controlling the local insect population around human settlements. Arthropods, including various species of spiders and insects, thrive in the tropical climate, though the island is free of highly venomous species.
Crabs are the largest land invertebrates, with Hermit Crabs scavenging along the beaches and other species creating holes in the jungle interior soil. Introduced mammals now form a permanent part of the island’s fauna, having arrived with Polynesian settlers and European traders. These include the Pacific Rat, as well as domestic animals like pigs, cats, and dogs.