Christmas Island (photo 1) is an Australian territory situated in the southern part of the Indian Ocean. With a population of around 2000 inhabitants, mostly belonging to the Australasian ethnic group, this island enjoys a unique reputation due to its discovery on Christmas Day. The story of its discovery can be told very quickly: the captain of the Royal Mary, a ship belonging to the British East India Fleet, accidentally found the island on December 25th 1643.
Photo 1
Located at 10°30′ lat S and 105°40′ long E, at a distance of 2600 kilometres from Perth, Australia, the island measures 135 square kilometres and is in fact the tip of an underwater sea-mount which is 4200 meters tall when measured from the ocean floor. This mountain has a volcanic origin and on its sides there are some limestone deposits created by the accumulation of coral reefs over the ages, which overlap older limestone deposits from the Oligocene. Because of the low latitude, Christmas Island enjoys a tropical vegetation and its abrupt shores host an abundance of coral reefs (Photo 2).
Photo 2
Their development has been favoured by the mild inter-tropical climate and with low variations in temperature from one month to another and thermal amplitudes of just 6 degrees (an average maximum temperature of 28ºC in April, the warmest month, and an average minimum temperature of 22ºC in August, the coldest month). The monsoons bring an average of 200 mm of rain each month during the rainy season but the rain does not occur at certain hours. Occasionally, the island can experience tropical cyclones that bring strong winds, heavy rain and high waves.
Christmas Island started to appear on British and Dutch maritime maps made during the 17th century under the direction of Dutch cartographer Pieter Goos. The first attempt to explore the island took place in 1857, and was carried out by the crew of the “Amethyst”. Even though the sailors tried to reach the highest point on the island, the expedition failed due to the inaccessible terrain. Only in 1872 and 1876, with the help of John Murray, a British naturalist, the “Challenger” expedition managed to scientifically explore the island. Ten years later, Flying Fish Cove, the capital of the island, was established and named by John Maclear, captain of a ship named “Flying Fish”, who discovered a cove on the shore of the island that harbored an impressive array of plants and animals. The following year, a team of naturalists on board the “Egeria” started to collect biological samples, plants and minerals. Among these minerals there were some pure phosphates that convinced the British to annex Christmas Island.
In terms of environmental protection, the most important aspect is the significant degree of isolation that allowed for the existence of such a large number of interesting, rare and scientifically important plant and animal species. The scientists that have recently investigated the island also undertook the necessary efforts to ensure its preservation, and nowadays, 63% of its territory is classified as protected and is included in a national park. The most important preserved species are those belonging to the virgin monsoon tropical forest environment, due to the fact that Christmas Island is situated in the path the monsoon for 6 months every year, between November and May. The Birds, which have suffered the effects of differentiation and speciation through the process of vicariation, have adapted to this environment by means of their biorhythm and the food that they eat, which is then processed by their digestive system and transformed into phosphates, such as guano, which is highly prized on the international market as a fertilizer.
Christmas Island was uninhabited until the last decades of the 19th century, which allowed for a number of species to evolve without any human intervention.
The flora
Tropical, evergreen forests grow in the deep ad oxide-rich soils of the island. There are 25 types of hardwood trees and many other species of orchids, ferns and shrubs. Among the 135 species encountered here, at least 18 are unique to this part of the world (Photo 3), such as Arenga listeri and Pandalus elatus, both of them trees, and Brachypeza archytas, an orchid. Despite the isolation, the island’s plants are in grave danger because of the expansion of the terrain used for mining phosphates, which has so far caused the destruction of many hectares of forest.
Photo 3
The fauna
The fauna of Christmas Island is even more diverse that its plant life and it is also better protected. The rats are represented by two species, Maclear’s rat and the Bulldog Rat (Photo 4), whose biogenetic centre is found on the island, but their survival is threatened by humans.
Photo 4
Seabirds are an attraction one should not miss, for tourists and scientists alike. Because of the numerous bird species, including endemic birds, represented by 5 species and 5 sub-species, and countless birds from 5 other species that do not live exclusively on this island, Christmas Island has attracted numerous conservation projects through the programs of Birdlife International. The most important birds found are the brown booby, the Christmas thrush and the imperial pigeon (Photo 5), which are joined by 86 other migratory species that visit the island.
Photo 5
Last but not least, the most protected inhabitants are the tens of millions of red crabs (Photo 6). They are a key element in the biological circuit of this environment because they recycle nutrients and maintain the biochemical structure of the tropical forest. So far, scientist have identified and described 20 species of crabs, adapted to the terrestrial environment and to the beaches affected by tides. The gum crabs, also known as coconut crabs, are the most abundant.
Photo 6
The larvae of red crabs are laid in the wet mud of the beaches that are washed twice a day by the tides. The constant shift between the ocean and the land is vital for their biology. Furthermore, each year, over 100 million crabs migrate, generally in November, at the beginning of the monsoon season and depending on the moon phases. Once they reach the ocean, the females release the embryos, which can survive for several weeks until they have developed enough to return to land. As it was mentioned before, the monsoon rains offer the preliminary conditions for this “march of the crabs” (Photo 7) to take place, but the migration is also tied to the phases of the moon. Thus, the eggs are laid exactly during the rising tide when the moon is in its last quarter.
Photo 7
The migration itself is also rigorously planned, and the first to reach the sea are the males, closely followed by the females. When they reach safety, at the edge of the forest, the males dig underground shelters and return one last time into the sea. This migration is visible everywhere on the island, as the crabs invade roads, beaches, gardens and even the bark of the trees. In order to avoid traffic accidents or just to ensure a safe passage for the crabs without hindering human activities, the rangers of Christmas Island National Park and some locals have worked to build protective screens along the roads to limit the space where the crabs can encounter traffic (Photo 8). This action was not sufficient, because crabs learned how to climb the screens and each day there were accidents in which crabs fell victim to cars (Photo 9).
Photo 8
Photo 9
Not willing to give up, the islanders decided to build passages under the roads for the crabs to pass from one patch of their habitat to another (Photo 10). This time, the plan worked and proved that crabs are intelligent creatures capable of adapting to their environment. Unfortunately, there was a problem that still needed to be solved, one that affects not only the crabs, but also other animals and even plants, and that problem is the intensive mining of phosphates which has altered vast areas of the island.
Photo 10
But, in order to end on a happier note, and in order to celebrate Christmas, which in Romania brought thermal inversions, dense fog and freezing rain in most of the country and bright sunshine and sunburns at altitudes of over 2000 meters, the inhabitants of this island and its tourists celebrate the holydays by scuba diving and taking photos of the multi-colour fish species, coral reefs, dolphins and sea-stars that inhabit the crystal-clear waters found around Christmas Island (Photos 11 and 12).
Photo 11
Photo 10
Having said that, we wish you, no matter where you are, what weather you are experiencing and what flora or fauna surrounds you, a Merry and Bright Christmas, from aboard the imaginary cruise ship that carried our minds to this Galapagos of the Indian Ocean, Christmas Island!
Sources:
***, Climate statistics for Christmas Island, Bureau of Meteorology. Retrieved on the 21st September 2011.
http://en.wikipedia.org/wiki/Christmas_Island
http://www.parksaustralia.gov.au/christmas/index.html
http://www.parksaustralia.gov.au/christmas/people-place/red-crabs.html#sthash.oV6tnsML.dpuf
http://www.bom.gov.au/climate/maps/
http://www.edgeofexistence.org/edgeblog/?p=793
Article written by Gabriela Adina Moroșanu and translated by Mihail Andreas Mitoșeriu
