Nature and science
ABC Radio National's Science Show | Christmas Island's environment
Most people know Christmas Island as a place for refugees. Few people know it as a place of natural beauty, where a unique ecosystem of plants and animals has developed over millions of years. Sharon Carleton visits Christmas Island and reports on efforts to protect this fragile environment. Listen to the ABC report
The annual red crab mass migration to the sea to spawn has been described by ecologists as one of the wonders of the natural world. This migration takes place each year after the start of the wet season synchronised with the cycle of the moon.
Christmas Island is also one of the world's most significant seabird islands for both the variety and numbers of its seabirds. More than 100 bird species have been recorded there including eight which breed on the island.
Its reefs support a rich marine life typical of Indian Ocean tropical reefs. The island also has unusual relict populations of back-mangrove species and cycads which were isolated when the island lifted. These include an internationally significant wetland which is a mangrove system growing in a freshwater spring 37m above sea level.
Christmas Island is the summit of a submarine mountain. It rises steeply to a central plateau dominated by stands of rainforest. The plateau reaches heights of up to 361 metres and consists mainly of limestone with layers of volcanic rock. The island is surrounded by a coral reef. There is virtually no coastal shelf and the sea plummets to a depth of about 5,000 metres within 200 metres of the shore.
Climate
The climate is tropical and temperatures range from 22°C to 28°C. Humidity is around 80-90 per cent and south-east trade winds provide pleasant weather for most of the year. However, during the wet season between November and April, it is common for some storm activity to occur producing a swell in seas around the Island. The average rainfall is 2,154 mm per annum.
Lister's gecko Lepidodactylus listeri
Find out more about Christmas island's weather from the Bureau of Meteorology.
Report on Christmas Island's biodiversity
The Christmas Island Expert Working Group (EWG) was formed in February 2009 in response to growing concern about the possibility of extinction of the Christmas Island pipistrelle (Pipistrellus murrayi), the island's only insectivorous bat. The working group quickly recognised that the threat of extinction of this bat was real, and that its status was a symptom of more general ecological management problems of the island as a whole.
Following an interim report, this view was endorsed by the Minister and the EWG was expanded and re-briefed to include examination of all threats to the island's ecology, biodiversity management and any other issues relating to the conservation management of Christmas Island and its surrounds.
The final report has highlighted the environmental threats facing the island and recommended additional actions to protect its native species.
Read the press release | Download the final report | Download the interim report
