BEHAVIOUR 



187 



Figure 103. An adult female Bottlenose Dolphin playing with a pelican feather. Photograph . 

 D. H. Brown, Marineland, California. 



playful than older ones, but they often nag their elders and betters into 



playing with them. The older generation do not seem to mind, and adult 



cows have often been seen 'borrowing' calves from other cows to share in 



the fun. 



Nor is this playfulness restricted to captive specimens. We have already 



spoken of whales turning somersaults (see Chapter 3) while diving^, but 



quite apart from such displays of high spirits, they like to play other 



games as well. Thus T. J. Terpstra reports that on loth August, 1955, the 



S.S. Akkrumdijk (Holland- America Line) passed a school of fourteen 



Sperm Whales at 35° N 52° W. While most of the animals swam away 



when the ship drew near, one Sperm Whale stayed on to play with a 



drifting plank, diving close beneath it and then turning round to give a 



number of repeat performances. Capt. Mörzer Bruins reports that 



cormorants and dolphins regularly play in the Bay of Bahrein, the 



cormorants swooping down on and pecking at the dolphins as the latter 



^Dolphins, as is well-known, leap into the air (Fig. 57), and Pilot Whales have often 

 been observed to come halfway out of the water in a vertical position. These actions are 

 performed both during and outside the mating season (see Fig. 196). 



