Christmas Island's Eccentric Resident

Text & Pix by Chua E Kiam
Nature Watch Vol 13 No 2 April 2005

 

A tiny island in the middle of the Indian Ocean beckons Chua Ee Kiam to partake of its wonders, no less than rare seabirds and crabs that walk from the mountains to the sea.

The crab was making its way across the road when it suddenly stopped in the middle of the road. I jammed my brakes to stop the car and jumped out with my camera. After taking a few shots, I noted that the carapace was dark-red ringed by fresh blood-red down to its limbs. It was the most unforgettable and colourful crab that I have even seen. As island residents say, the first crabs you meet, will certainly be the most exciting and memorable. A large robber crab trudged across the road was also greeted by another barrage of flashes. Excited, I rushed back to show the digital images to my companions who were barely awake in the car. Certainly this lucky encounter augur better moments to come.

Loud thuds on the drainpipes were music to our ears during one of the relatively warm mornings at Sunset Lodge. The spectacle of the much promised mass migration had arrived. It had not rained for the past three weeks although clouds hung heavy in the sky. A large amount of rain are necessary to trigger the red crabs to make the journey from forest to shore.

Even the Robber Crabs were getting edgy as they wait in vain for a feast of red crabs which will inevitably be crushed by vehicular traffic during their “trek”. More about the crabs later on.

On our first day after arrival, we had an orientation drive to familiarise ourselves with the island. The island has only two traffic lights because a road near the shore is so narrow that vehicles can only travel in one direction at any one time. And it is also best to steer clear from the heavy trucks or road trains (as they are more commonly called) that operate day and night.

A slide presentation further heightened our curiosity about what the island had in store. One of the presenters Linda Cash's enthusiasm was so infectious that some of us went snorkelling and scuba-diving although many had not planned to do so. Even in the shallows at the Flying Fish Cove, I came face to face with a two-foot long parrot fish! All I can say is that the fishes gawked at me more than I could gawk at them. It was a riot of colours with so many fishes near the shore in crystal-clear waters. Butterfly fish, wrasses, surgeonfish and many more that I have no inkling of their ID, were abundant and I can only imagine what an experience scuba diving would be.

David James's introductory night walk in the forest was a revelation to the many not exposed to its famous nocturnal denizens. Residents of Christmas Island joke that the crabs cost about A$2,000 each, that is, in fines and instant deportation. It was not surprising that crabs are not featured in their menus or diets.

We were introduced to nature trails by Captain Don who has actively combed the whole island to mark out trails for trekking. Red Crabs were everywhere and our feet often sank into their burrows. If not for the lack of rain, we would have been greeted by a sea of crabs on the move.

 

 

 
     
     
     
     
     
     
     
     
     
           
     
     
     
 
Abbots Booby
 
Silver Bosunbird
   
     
         
 
       
 

However, when we returned later to the main road in the evening, thousands of red crabs were already migrating towards lowlands. The light rain did in fact set the motion as thousands gathered to march to the sea. The spectacle was enough to drive us delirious. Some roads had to be closed to minimise the fatalities. But a sudden brief downpour only serve to confuse them further. Plastic skirtings along certain roads helped channel the crustaceans to tunnels under roads. I was also under the impression that the crabs would have to migrate across less treacherous terrain. I had not expected that the crabs to have to navigate down steep forest inclines and sheer cliffs (more than 20 metres in some places), taking a week to make their descent. Truly only the fittest and the luckiest survive. And these crabs are by no means small. Female Blue Crabs and Robber Crabs also migrate to the sea for spawning but because of its smaller numbers the migration is not as spectacular as the Red Crab's.

Later in the night, we realised that the Red Crabs are diurnal and most of them would have found their burrows by sunset. But the Robber Crabs are active. We saw hundreds lined on both sides of the roads feeding on the flattened red crabs run over by vehicles. And on other evenings when the Red Crabs did not migrate, only a handful of Robber Crabs can be seen. They knew somehow where their potential food source would be. At the Dales, we saw even more Robber Crabs especially with the presence of the Arenga Palm ( Arenga listeri ); their favourite food. Blue Crabs were conspicuous where there are freshwater streams at the Dales, Hosnie's Springs and also along some damp stretches on the way to Greta Beach.

Not to be missed is the daily bird feeding sessions with Max Orchard. Sea bird fledglings (orphaned or sick) found outside their nests are brought by residents to Max's place next to the Park's office. The birds are territorial and have been given their own resting place (usually a chair) which each would jealously guard against other birds. Frigatebirds, Abbot's Boobies, Red-footed Boobies and the Silver Bosuns were only too glad to receive handouts from their surrogate parent until they can fly and hunt on their own.

 

Hosnie's Spring is not open to visitors and we were most privileged to have a guided tour by Mick Jefferies, a Park's staff. The road leads to Greta Beach before branching off and four-wheel drive vehicles are required. Covered shoes are a must due to the widely scattered limestone rocks on the undulating terrain that are extremely sharp and will sheer off soft tissues. Fabric or leather gloves are also handy in order to steady oneself. We trekked across jungle dominated by the huge fig trees ( Ficus microcarpa ). An abundance of Blue Crabs were seen scurrying for cover with our arrival at the streams. Such a mangrove forest that survives only on freshwater is an enigma – Earth movements probably isolated the interior millions of years ago and hence this unusual and rare habitat.

Some of the memorable moments include watching the elegant Golden Bosun birds (Phaethon lepturus ) gliding at Margaret Knoll. Their apricot sheen and long yellow tail streamers makes it one of the most beautiful seabirds. The hundreds of CI Flying Foxes returning to roost at the Knoll was also unforgettable. Near a temple at the golf course, frigatebirds soared magnificently and dipped into the Indian Ocean for the daily meal. Early mornings are best for watching the Robber Crabs. There were so many robber crabs that we could take a group photo of them. Here they were more orange or blue unlike the dark brown ones I have seen at Sipadan. Although most of the Red Crabs are bright red, we saw some orange ones and there were reports of the rare purple ones. The mass of CI Imperial Pigeons at the watering hole at the Hosnie's Springs, the Australian Kestrel landing on a side post a few feet away from where we parked our car, Brown Boobies at Winifred Beach; it was an experience of a life-time. Listening to hoots of the rare, endemic and elusive CI Hawk-Owl ( Ninox squamipila natalis ) was good enough for the time being. We have an excuse to come back again.

Expect to be sprayed at the Blowholes. As the tidal waves hit the pinnacles, water is forced through the openings to create the spectacular “ejections”. Fishing at the Blowholes was rewarding as our fellow travellers experienced. Although we did not see any turtles, we had to be content with their tracks. Dolly Beach has a decent stretch of sand but be prepared to guard your food as the Robber Crabs (now I see the connection of its name) is on the prowl. I saw the largest free-swimming lobster at the shore at Winnifred Beach and was more content photographing it than thinking of sashimi

 

The island is so isolated that it has also become centre of endemic plants and animals. It was “Christmas Island this” and “Christmas Island that”. Other than the endemic Red Crabs we also chanced upon the CI Gecko, CI Frigatebird, CI White-eye, CI Thrush, CI Imperial Pigeon, CI Emerald Dove, CI Flying Fox, CI Stick Insect, CI Hoya and the Golden Bosun and Abbots Bobby – all found nowhere else in the world!

 

After a week, the rains remained elusive but it was time to leave. This exploratory first visit certainly entices us to return to experience nothing less than millions of crabs on the move. Some day perhaps. As the plane took off, I could see the threatening rain clouds but even then, the red crabs will wait for the spring tides during the next full moon which is still three weeks away. They know somehow when to migrate.

Whilst they wait, they have to contend with the widespread invasion of the exotic yellow crazy ant ( Anoplolepis gracilipes ) that has wiped out huge populations of these crabs and other ground dwelling animals and wrecking havoc on the forest ecosystem. The National Park has embarked on a programme to manage the ants but total eradication is impossible. The red crabs will still be there to receive visitors but perhaps in lesser numbers. But in future, visitors may also be able to view more than just crabs for a satellite launching facility is currently being built at South Point.

 
   
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Acknowledgements:

Special thanks to staff of Christmas Island Tourism Association (CITA) and Christmas Island National Park for making our stay more memorable.

Getting there

Scheduled flights to Christmas Island leave from Bali and Perth

Getting Around

4WD vehicles are recommended and must be booked in advance

References:

1. Christmas Island Naturally, (2 nd Edition), 1981, HS Gray, Christmas Island Natural History Association

2. Christmas Island National Park Management Plan 2002