Cook Islands Biodiversity & Natural Heritage

Birgus latro


Coconut Crab

Multimedia & Additional Resources

Type Description Download
Open this image in pop-up window Image: Coconut crab and coconut husks, Line Islands 75KB
Open this image in pop-up window Image: feeding in pandanus (Pukapuka) 71KB
Open this image in pop-up window Image: Juvenile and adult coconut crabs 70KB
Open this image in pop-up window Image: Female showing rear legs 33KB
Open this image in pop-up window Image: Juvenile - 10mm Thoracic Length 36KB
Open this image in pop-up window Image: Walking Larva (glaucothoe) 64KB
Read this article Article: The Young Coconut Crab Open in new window
Gerald McCormack, September 2005

General Information

COMMON NAMES: Coconut Crab, Robber Crab; French Crabe de cocotier

TRADITIONAL NAMES: Kaveu / Unga ‘Onu < Kaveu (RR), Unga Puku‘ara (MG), Unga Kaveu (AT AK RK), Toromimi < Unga Kaveu / Unga (MK), Ūngākave‘u / Toromimi < Ūngākave‘u (MT), Kaveu (TS TW PK), Unga Koveu (MH)

GLOBAL DISTRIBUTION: NATIVE islands only: Mauritius - Tuamotu; n. to s.Japan, s. to New Caledonia. (Not in Australia, nor Papua New Guinea)

COOK ISLANDS STATUS: Native; Land, breed in ocean; Coastal, preferring dense forest cover, within a few kilometres of teh ocean.


KEY FEATURES: The largest land-crab, deep blue or tinged red. Thorax is wing-like, with a central "wishbone". The left claw (chela) is massive, the right smaller. Two pairs of walking legs (periopods), and smaller hind pair of appendages with terminal claws. FEMALES have 3 large feathery pleopods under the abdomen to support teh egg mass.

Enlarged Image of 'Birgus latro'

Cook Islands Distribution

View Distribution Map View Distribution Map

Southern Group: Present    Makatea: Present

Northern Group: Present

Key to Symbols

Scientific Taxonomy

Birgus latro (Linnaeus, 1767)
TAXONOMY: ANIMALIA; ARTHROPODA; CRUSTACEA; MALACOSTRACA; EUMALACOSTRACA; Eucarida; Decapoda; Reptantia; Anomura; Paguroidea; COENOBITIDAE. COMMENT: "latro" means "robber".

More Information

SIGNIFICANCE NOTES -. Comment: NBSAP - Mauke (1 of 3 wild animals), NBSAP - Mitiaro (1 of 10 wild animals), NBSAP - Mangaia (4 of 5 wild), NBSAP - Atiu (1 of 5 wild)

GENERAL NOTE: Fully terrestrial, drinking water - including seawater. Their "lungs" are the gill chambers, which are aerated by a paddle-like remnant of the gill. They drown if kept in seawater. Mating occurs near the sea and involves the male pushing the female onto her back and using his 5th periopod to place the sperm-sac (spermatophore) over the gonopore at base of the walking legs. After this the female lives within 100 metres of the sea to regularly moisten herself with seawater. 1-2 weeks after mating teh female extrudes the eggs past the sperm-sac so they are fertilized and holds them in a mass with her abdomenal pleopods. The eggs take 3-6 weeks to mature. The young (as zoea) are spawned from the eggs into the water around the first and last quarters. The zoea takes 3-6 weeks to go through 4-5 zoea stages and form an ampbibious stage called a glaucothoe. The benthic, shrimplike glaucothoe finds a minute shell and after 3-4 weeks it migrates ashore. After about 4 weeks of living around the high tide mark, it transforms into a juvenile crab, which continues to use a gastropod shell for 1-2 years, and lives very secretively in burrows. Smallest without a shell had TL of 4mm, probably all have discarded the shell by TL 6mm. Crabs burrow and moult 2-4 times a year up to TL 30mm (immatures), and, when adult, they moult once a year. They are solitary and usually nocturnal, especially where human activity is frequent. They are omnivorous, commonly eating the fallen fruit of Pandanus and the Coconut Palm. They use their main claws to pull back the husk at the end which was formerly attached to the palm. When the eyes are exposed they pierce the soft-eye with a walking-leg claw, expand the hole with the small pincer on the third walking-leg, and finally enlarge the hole with the main pincer. The process takes several days. The Coconut Crab is esteemed as food. Unfortunately, it is easily over-harvested, because of its complex life-cycle and slow growth rate.

Vouchers & References

Rarotonga: fieldspecimen, s.Muri home of Gwen Welland, Oct/2005, dead, blue, 72mmTL (~30 years old), G.McCormack with ID as Birgus latro. Atiu: field-specimen, College collection, 10/2000, ID GMcC. Pukapuka: fieldspecimen+photo, 2/2004, G.McCormack with ID as Birgus latro.

Special Reference: Yaldwyn & Wodzicki 1979;

Data Update History (information):
zTX, zB02, zM02, zD02

Web Resources

Citation Information

McCormack, Gerald (2007) Cook Islands Biodiversity Database, Version 2007.2. Cook Islands Natural Heritage Trust, Rarotonga. Online at Copy citation to system clipboard
Please refer to our use policy.

Search Biodiversity Database Biodiversity Database

More Options | Help
My List My List



Copyright © 2007 (July) The Cook Islands Natural Heritage Trust, all rights reserved.
Copyright & Use Policy