Snake Island (known locally as Pulau Kalampunian Damit) is a tiny island 55 km south of Kota Kinabalu on the west coast of Sabah, Malaysian Borneo.
This tiny island only c. 100 x 150 meters is well known to naturalists for 5 reasons.
- Snake Island hosts the best known communal breeding site for the highly poisonous Yellow-lipped Sea Krait with up to 150 snakes recorded at one time.
- A pair of White-bellied Sea Eagles has nested on the island for many generations. These eagles were the subject of a famous National Geographic film The Eagle and the Snake.
- The island is one of a few frigate bird roosting islands around the coast of Borneo with hundreds of frigate birds recorded roosting from time to time.
- Snake island is one of a very few sites in Borneo where the seabird dispersed tree Pisonia grandis has been recorded.
- As of January 2021 Snake island hosts the densest population of strangling figs (of 3 species) known in Borneo.
This article describes a vegetation survey of Snake island carried carried out on 04 January 2007 by Anthony Lamb and Quentin Phillipps when the vegetation was dominated by Pisonia grandis trees. In 2007 there were only two mature figs on the the island. A very large Ficus microcarpa hosting a sea eagle nest and a smaller younger Ficus drupacea.
A second article describes a second vegetation survey carried out 14 years later on 22 December 2020 by Shavez Cheema and Chun Xing Wong of 1 Stop Borneo Wildlife. During the 14 year gap between surveys the Pisonia trees were almost entirely replaced by three species of strangling figs.
The entrance to the island in 2007. Because there was no jetty the island could only be approached at low tide. Note that the island vegetation is completely dominated by the yellowish leaves of Pisonia grandis trees, These seeds of these trees were brought to the island by roosting frigate birds which nest on islands off the coast of N Australia but spend much of the year off the coast of Borneo. The seeds of P. grandis are sticky and cling to their feathers of the frigate birds.
Note that rocks underneath the Pisonia grandis trees are relatively bare with only one sapling to replace the adult trees when they die. Note also that the ground is covered with with white bird droppings or guano. Guano is widely used as a valuable fertilizer in many locations worldwide.
This ancient Pisonia grandis tree has not long to live. Note the Ficus drupacea sapling on the right growing on the roots of the Pisonia, a ready, able and willing usurper of the old tree.
The leaves of the Ficus drupacea sapling are speckled with guano from the nesting sea eagles and the roosting frigate birds. The ideal fertilizer on this rocky island with no soil.
In 2007 the second highest tree on Snake island was this young but vigorous Ficus drupacea strangler. Tony Lamb shows the scale.
The tallest tree on Snake Island in 2007 was this Ficus microcarpa which was hosting a White-bellied Sea Eagles nest.
This curious youngster stayed to watch as we surveyed the vegetation of Snake Island.