The island is home to 81 different species of birds, some of which are considered rare or endangered. For some birds, such as the regent parrot, the Shark Bay region marks the northern limit of their range. For ospreys, pelicans and other seabirds, Dirk Hartog Island is an ideal place to nest. Each spring more than 65 species visit during their migration from the northern hemisphere.
The first extensive collection of reptiles were collected from Dirk Hartog Island in 1977, during which it was discovered that the island’s reptiles species are typical of the warmer, drier areas of South Western Australia. Some of the species found on the island are either endemic or rare and include the Skink ctenotusyoungsoni.
Dirk Hartog Island is home to rare Burrowing Sand Hill frog (Arenophryne rotunda). It lives in sand hills, in a burrow 10 cm below the surface. The young frogs hatch directly from clutches of creamy white eggs laid in moist sand, some 80 cm below the surface.
The beaches on Dirk Hartog Island are home to many different species of crabs. The most common ones are mud crabs and ghost crabs.
Shark Bay is home to the world’s most significant Dugong population – 10,000 to 12,000 animals, or 10% of the species. The bay’s protected waters and plentiful seagrass meadows are perfect for the dugong, the world’s only marine mammal herbivore. During midwinter dugongs spend most of their time in the sea grass beds adjacent to Dirk Hartog Island.
Loggerhead turtles are the most endangered species of turtles to nest in the Shark Bay area and indeed the Australian region as a whole. Turtle Bay, located at the island’s north is the species’ main nesting ground. Turtle Bay to Dampier’s Landing are the species’ nesting ground.
Humpback whales are seen around the island during their northern and southern migration. The population that migrates along the coast of Western Australia numbers more than 20,000 and is the largest in the world. Whales travel south with their calves and swim in the protected, shallower waters much closer to the coast. Humpback whales pass Dirk Hartog Island from July to October.
Sea snakes are very good divers considering they are air breathing animals – they can dive up to 100m or more and remain underwater for up to 2 hours. Sea snakes are highly venomous, though they rarely attack people unless provoked.
The waters surrounding the island are home to many pods of dolphins. One of the world’s best-known and most-loved species are the Monkey Mia Bottlenose dolphins that attracts thousands of visitors each year into the Shark Bay region.
Sharks are always spotted around the island. The most common sharks include lemon sharks, shovel nose sharks and tiger sharks.
The waters surrounding the island are home to hundreds of fish species, including whiting, flathead, snapper, yellowfin tuna and dolphin fish, just to name a few.