THE FAUNA OF KRAKATAU, VERLATEN ISLAND 



AND SEBESY 



by 



Dr.*K. W. Dammerman 



(Buitenzorg Museum). 



The terrible eruption of Krakatau, August 1883, has been an unex- 

 pected opportunity for biologists as perhaps will not occur for years. 

 Although the consequences of the disaster were dreadful, no less than 30,000 

 people having perished, this experiment of Nature is of most interest for 

 zoogeographical problems, especially how a barren island, wholly destitute 

 of animal life, is reoccupied again. 



The question about the total devastation of the fauna of the islands 

 of the Krakatau-group in 1883 cannot be settled absolutely, but there is 

 every evidence that no animal could have survived the eruption. From the 

 20th May till the 26th August the explosions followed each other with 

 short interruptions, covering the islands with stones and ashes. By the 

 last and most violent explosion the volcanoes Danau of 450 M. in height 

 and Perbuwatan disappeared altogether, and the Peak of Rakata or Krakatau 

 of 800 M. was split in its very midst and one half blown away. The three 

 islands which remained after the eruption, Krakatau (Krakatoa), Verlaten 

 Island (Forsaken I.) and Lang Island, were overshed by hot ashes, a layer 

 of 30—60 M. thickness! No animal could have remained in his hiding 

 place during the explosions and, buried by the ashes, it could not have 

 escaped from destruction, the bottom layer of ashes remaining hot for days. 

 The possibility that a single animal, concealed in a recess of the rocks, 

 survived the disaster may be maintained, but such an animal would have 

 perished after a short time as no food was available, the whole vegetation 

 also being destroyed or burnt. All biologists who have visited the islands 

 after the eruption are of the same opinion. But granted to sceptics that 

 a single animal did survive and could maintain itself after the eruption, 

 this is of little or no importance, for certainly 99 ^Jq of the animals living 

 now on the islands are new invaders. 



Now let us see what questions arise from the Krakatau-problem :— 



1. First of all we may put the question:— In what sequence have animals 

 reached. the islands? 



2. How far is the present condition of the fauna to be considered as normal ? 

 The answer would give us an indication of how long it will be before 

 the islands again possess a fauna as rich as before the eruption. 



