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Christmas Island Super Predator


Christmas Island Super Predator
Photo Information
Copyright: James Parker (Jamesp) Gold Star Critiquer/Gold Note Writer [C: 1369 W: 9 N: 6334] (18906)
Genre: Animals
Medium: Color
Date Taken: 2006-04-21
Categories: Crustacia
Camera: Canon EOS 1Ds MkII, Canon 24-70 mm f 2,8 L-USM
Exposure: f/2.8, 1/50 seconds
More Photo Info: [view]
Photo Version: Original Version
Theme(s): Christmas Island [view contributor(s)]
Date Submitted: 2007-10-09 10:10
Viewed: 10353
Points: 22
[Note Guidelines] Photographer's Note
Today I have chosen a shot from Easter 2006. It shows a (smallish) Robber or Coconut Crab , which is the top land predator on Chistmas Island where crabs rule the ecosystem. These crabs are totally unafraid and will stand their ground against anything - even lorries! They are not totally defenceless - during the migration/mating season they maraud over the island. They have a reputation for puncturing car tires - the record being 14 in 24 hours (and there are only about 1,500 people on the Island)!

I took this shot in the Rainforest - it was quite dark - and the crab wasn't stopping!!

CRAB DATA

Coconut crabs live in areas throughout the Indian and western Pacific oceans. Christmas Island in the Indian Ocean has the largest and best-preserved population in the world. Large populations also exist on the Cook Islands (Pacific Islands), especially Pukapuka, Suwarrow, Mangaia, Takutea, Mauke, Atiu, and Palmerston Island. Other populations exist on the Seychelles, especially Aldabra, Glorioso Islands, Astove Island, Assumption Island,Bowen Island and Cosmoledo, but the coconut crab is extinct on the central islands. They are also known on several of the Andaman and Nicobar Islands in the Bay of Bengal. There is some difference in colour between the animals found on different islands, ranging from light violet through deep purple to brown.

As they cannot swim as adults, coconut crabs over time must have colonized the islands as larvae, which can swim. However, due to the large distances between the islands, some researchers believe a larvae stadium of 28 days is not enough to travel the distance and they assume juvenile coconut crabs reached other islands on driftwood and flotsam.

The distribution shows some gaps, as for example around Borneo, Indonesia or New Guinea. These islands were within easy reach of the crab, and also have a suitable habitat, yet have no coconut crab population. This is due to the coconut crabs being eaten to extinction by people. However, coconut crabs are known to live on the islands of the Wakatobi Marine National Park in Sulawesi, Indonesia.

The diet of coconut crabs consists primarily of fruit, including coconuts and figs. However, they will eat nearly anything organic, including leaves, rotten fruit, tortoise eggs, dead animals, and the shells of other animals, which are believed to provide calcium. They may also eat live animals that are too slow to escape, such as freshly hatched sea turtles. During a tagging experiment, one coconut crab was observed catching and eating a Polynesian rat. Coconut crabs often try to steal food from each other and will pull their food into their burrows to be safe while eating.

The coconut crab climbs trees to eat coconuts or fruit, to escape the heat or to escape predators. It is a common perception that the coconut crab cuts the coconuts from the tree to eat them on the ground (hence the German name Palmendieb and the Dutch Klapperdief). However, according to the late German biologist Holger Rumpf (sometimes spelled Rumpff) the animal is not intelligent enough for such a planned action, and rather accidentally drops a coconut while attempting to open it on the tree. Coconut crabs cut holes into coconuts with their strong claws and eat the contents; this behavior is unique in the animal kingdom.

It was doubted for a long time that the coconut crab could open coconuts, and in experiments, some have starved to death surrounded by coconuts. However, in the 1980s Rumpf was able to observe and study them opening coconuts in the wild. The crab has developed a special technique to do so: if the coconut is still covered with husk, it will use its claws to rip off strips, always starting from the side with the three germination pores, the group of three small circles found on the outside of the coconut. Once the pores are visible, the crab will bang its pincers on one of them until they break. Afterwards, it will turn around and use the smaller pincers on its other legs to pull out the white flesh of the coconut. Using their strong claws, larger individuals can even break the hard coconut into smaller pieces for easier consumption.

gerbilratz, taba, gracious, nglen, Necipp, rousettus, Adanac, uleko has marked this note useful
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Critiques [Translate]

He's a real ugly dude, but looks ain't everything...lovely picture and great text.

  • Great 
  • joey Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 1739 W: 224 N: 6872] (24909)
  • [2007-10-09 10:25]

I've heard of this beast!
Huge things with massive claws that can crush bone (or something like that)
Great image of this satan of crabs.
+++ Excellent POV that clearly shows its formidable claws. Good sharpness and detail. Decent DOF.
--- Nothing :)
Well done,
Joe

  • Great 
  • taba Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 466 W: 124 N: 312] (1847)
  • [2007-10-09 11:03]

Hi James
great capture and details. also on the notes...
good colors, itīs an incredible animal...
well done.
Taba

Hello James,
Thank you for sharing this awesome crab with us!
I had seen them in Sipadann island in the triangle between Philippine, Sabah and Indonesia Kalimantan!
The awesome power on their claw is amazing but seeing them bring the coconut down from the tree!
captured well with exposure and focus even in motion!
thanks for sharing again
cheers
Tony

  • Great 
  • nglen Gold Star Critiquer/Silver Workshop Editor/Gold Note Writer [C: 2883 W: 30 N: 9683] (36145)
  • [2007-10-09 11:41]

Hi James. you say smallish crab looks big to me. what a great looking one ut is. as you say it was not stoping for you. good detail and natural colours. well done TFS. interesting notes thanks.
Nick..

Wow Christmas Island anywhere you haven't been? fine shot nice quality good details. very well composed with a diagnol log. The fern like leaves frame it well. tfs rgds Necip.

Hi James,
Very nice shot of this interesting crap, which I know this Coconut crab from books and documentary film. Great focus, details, light, colors and composition.
good and informative notes.
thanks for sharing
best wishes
Ahmet

  • Great 
  • arfer Gold Star Critiquer [C: 2731 W: 0 N: 0] (0)
  • [2007-10-09 19:58]

Hello James

I have seen the photos of the dead crabs on the roadways and the hundreds of other ones marching along.It would drive me batty as I hate to drive over living creatures and have been known to get the willys just driving on a rainy night when my friends the frogs are crossing the roads.Nicely focused with excellent detail and colour.I would love to get there someday and see them for myself.TFS

Rob

  • Great 
  • pvs Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 1127 W: 254 N: 3161] (14464)
  • [2007-10-09 23:59]

Hi James,

Easter at christmas Island,sounds good to me,

This is a nice capture even the crab was on the move you managed to capture this tire puncturer,well done and thanks for the informative note,
Paul

  • Great 
  • Adanac Gold Star Critiquer/Gold Note Writer [C: 1273 W: 1 N: 6188] (21378)
  • [2007-10-10 14:37]

Hello James,
Good image of one of the ugliest crabs I have seen, Nice focus and exposure, thanks for sharing.
Rick

  • Great 
  • uleko Gold Star Critiquer/Gold Star Workshop Editor/Gold Note Writer [C: 3396 W: 172 N: 3310] (10940)
  • [2007-10-16 6:25]

Hello James,
Interesting note and a fine capture of this vicious crab. I like your composition showing it in a natural environment. Excellent sharpness and fine colours. The claw looks enormous!
TFS and best wishes, Ulla

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