For nature lovers, Christmas Island National Park provides fantastic opportunities to observe unique plants and animals in their natural habitats. The park covers about two thirds of the island. As an isolated oceanic island, distant from other land masses, Christmas Island is home to a high proportion of endemic species. Several are endangered. The park protects significant ecosystems including much of the island's uniquely structured rainforests and two wetlands of international importance, the Dales and Hosnie's Springs. In and around the national park you will find a host of native sea and forest birds, unique marine life and land crabs — including tens of millions of red crabs, famous throughout the world for their spectacular annual breeding migration.

On the world map of fishing locations, Christmas Island may only rate a small dot, however fish being caught here are making a big mark amongst the international fishing fraternity. The secret is out! Anglers around the world are starting to find out that Christmas Island is the hottest new spot for big fish in South East Asia. Within a few hundred metres of the boat launching facilities, it is possible to fish in thousands of metres of water for Sailfish, Tuna, Wahoo and all the other exciting species that you usually find in tropical locations. The difference is that on Christmas Island the fish are BIG, very BIG. When the ocean currents bring the tuna in, it is possible to see fish in excess of 100 kilograms feeding on the surface. While the Yellowfin Tuna roam and pass the island quite regularly, Dogtooth Tuna live permanently on the steep drop-offs that surround Christmas Island. Some of them grow to be over 80 kilograms. If you prefer the high flying aerial displays of a sailfish, during the pre-monsoon months some of the biggest Sailfish in the world are to be found around Christmas Island. Even trolling within a few hundred metres of the shoreline you will find the razor gang. Wahoo are the fastest fish in the world and Christmas Island is their favourite racetrack.

Tens of millions of red land crabs live on Christmas Island. They are the Island's keystone species, because they play a vital role recycling nutrients and shaping and maintaining the structure of the rainforest. At the beginning of the wet season (usually in October/November), most adult Red Crabs suddenly begin their spectacular migration from the forest to the coast, to breed and release eggs into the sea. Breeding is usually synchronised island wide. The rains provide moist overcast conditions for crabs to make their long and difficult journey to the sea. The timing of the migration breeding sequence is also linked to the phases of the moon, so that eggs may be released by the female Red Crabs into the sea precisely at the turn of the high tide during the last quarter of the moon. It is thought that this occurs at this time because there is the least difference between high and low tides. The sea level at the base of the cliffs and on the beaches, where the females release their eggs, at this time varies the least for a longer period, and it is therefore safer for the females approaching the water's edge to release their eggs. Sometimes there are earlier and later migrations of smaller numbers of crabs, but all migrations retain this same lunar rhythm. The main migration commences on the plateau and can last up to 18 days. Masses of crabs gather into broad "streams" as they move toward the coast, climbing down high inland cliff faces, and over or around all obstacles in their way, following routes used year after year for both downward and return migrations. Movement peaks in the early morning and late afternoons when it is cooler and there is more shade. If caught in open areas, in unshaded heat, the crabs soon lose vital body moisture and die. The crabs will migrate to the coast, where the males will dig mating burrows and they will mate. After mating, the males will commence their return migration. The females will brood their eggs for 12-13 days before emerging from the burrows to commence spawning. The females will commence their return migration immediately after spawning. The eggs hatch into free swimming larvae immediately after they are dropped into the sea. The larvae grow through several stages in the ocean for over four weeks before emerging from the sea to become tiny crabs.