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G. PILLERI 



e) Resting on the bottom of the pool 



I do not agrée with Mohr's statement (1964) that the Inia swims day and 

 night and swims slightly slower when sleeping. It has not been proved that slow 

 swimming means sleep. Marine dolphins (Globieephala, Grampus) lie motionless 

 on the surface of the water for several seconds. Thèse could be short periods of 

 sleep. In Marineland I saw the Inia lying quite motionless on the bottom of the 

 pool (fig. 24, 25). Thèse periods could also be described as short sleeps although 

 this has not yet been proved physiologically. 



f) Play behaviow 



According to the local population in Puerto Almacén and Mrs. Monika 

 de Harjes who, together with her father, filmed the fauna of Bolivia, the buffeos 

 can show certain patterns of play behaviour. They will accompany a canoë to 

 play with or bite at the paddles. They always follow the canoë and never swim 

 in the bow wave as do the marine dolphins (Delphinus delphis). They have also 

 been seen trying to support overturned canoës. Scientific proof of thèse behaviour 

 complexes would be extremely valuable for the ethology of the Ceteceans. 



g) Flight behaviour 



During the whole of the expédition, the Inia remained relatively shy. If an 

 attempt was made to approach and follow the animal it would dive and then surface 

 to spout only once. If the chase was continued, the animal would remain under 

 water, change direction and swim under the boat and surface 100 meters behind 

 the boat to spout. Similar behaviour was seen by Twsiops truncatus in the western 

 Mediterranean (Pilleri and Knuckey 1968). On the other hand if the motor 

 was stopped and the boat was rowed very slowly, the animal often approached 

 curiously. 



h) Epimeletic behaviour 



If an animal was shot at and wounded, and if a second buffeo was in the same 

 territory, the second animal would immediately approach the first and accompany 

 it at its side. This approaching and accompanying cannot be described as epimeletic 

 behaviour such as seen by Pilleri and Knuckey (1968) by Delphinus delphis in 

 the western Mediterranean. Distress signais of Inia have not been registered. It is 

 surprising how quickly the animal quietened after the first shock of being wounded. 

 It would swim quite normally except that it would surface more frequently to blow. 

 The résistance against rifle wounds shown by ail animais was quite astonishing. 



The second animal caught (No. 418, 9, body length 208 cms.) was very scarred. 

 Both flippers, on the dorsal as well as the ventral surface, and the flukes were 



