422 PERCY SLADEN TRUST EXPEDITION 



imbricata), and probably the logger-head (Thalassochelys caretta) occur; and, though these 

 can hardly be considered land animals, it is most convenient to consider them in conjunction 

 with their relative, the land tortoise. The green turtle occurs in enormous numbers, 

 which are perhaps only equalled in Assumption. There are two divisions, marked by 

 the season at which they lay their eggs. In the season of S.E. Trades only a small 

 number of turtles stay round the coast and breed, while in December, at the beginning of 

 the N.W. Monsoon, an enormous horde of turtles arrives off the atoll and remains until 

 May. The origin of this migratory horde is open to some doubt, for, since turtles only 

 frequent shallow water where they can get food, they must either live near the shore or on 

 a shallow bank : they have not been recorded from the latter and therefore it must be 

 supposed that they come either from Madagascar or the coast of Africa. Presumably the 

 number of suitable islands for breeding is now small on account of the fact that most have 

 been long settled. Assumption, however, was only colonised in 1908, and Aldabra is so 

 large that until recently the people of the settlement have not disturbed much of the 

 coast. Turtles are now being killed so rapidly and the waste is such at both Assumption 

 and Aldabra that their numbers are already markedly on the decrease. 



The turtles on arrival extend round the shore and pair, during which process great 

 fights take place among the males for the females. The latter ascend at night the small 

 sand beaches, which occur at intervals along the coast, and dig deep holes in the sand, 

 the fore-flippers being chiefly used for the task. The holes may be only a few feet above 

 high-tide mark, or at some distance from the shore, as in the case of one found on the top 

 of Dunes Jean Louis (60 ft. high). The number of eggs laid is about 200 and the females 

 are supposed to come up the beach twice in each season. They always ascend with one 

 flowing tide and go to sea again on the next ; consequently a night with the tide becoming 

 high at sunset is the most favourable. 



The young turtles hatch in 40 days and go straight down the beach to the sea. The 

 hatching of all the eggs in a nest takes place almost simultaneously, and the young turtles 

 dig their way up out of the sand as fast as they can be counted and crawl down to the sea 

 in a long procession. By what sense they find the right direction was not discovered ; their 

 eyes are not open but even if placed on a flat surface they know their way to the sea. 

 The hatching of the whole nest only takes about 10 minutes and forms a remarkable and 

 pretty sight. The mature turtles are either speared from a boat or are turned on the 

 beach, the latter method being very destructive, for only females are caught and this 

 occurs as a rule before they have time to lay their eggs. Steps will have to be taken to 

 preserve the eggs, if the green turtle is to continue to exist. 



The hawksbill turtle (Chelone imbricata) is much scarcer than the green turtle. It 

 ascends the beach in the day to lay its eggs, which are said to take 60 days to hatch, and 

 the female is supposed to come at least twice, at an interval of a fortnight, to lay in the 

 same place. Those turtles, which have lived long in the lagoon, are always coated with 

 a layer of mud, and this prevents the " tortoise shell " from developing dark markings, the 

 absence of which adds considerably to its market value. Their natural food has been said 

 to consist of fish, but this did not seem to be the case on Aldabra, as a fisherman, who 

 had spent twenty years on the atoll fishing hawksbill, said he had never found fish in 



