TRAVELS OF WATERFOWL 



moment he makes the next move — pressing down on his hands — I am 

 rising too, ready to bid him goodbye. Children quickly learn to interpret the 

 actions of parents or teacher, anticipating pending behavior on the basis of 

 signals. 



As with voice signals, there may be interspecific responses to action sig- 

 nals. When I approach a flock of mixed species of ducks loafing on a sand 

 bar, they all raise their heads, regardless of the species of the individual that 

 first responded to my presence. Many species of ducks react to the alarm 

 signal of Canada Goose, and these geese to the actions of ducks. Feeding 

 actions draw interspecific responses ; ducks of many kinds react to the feed- 

 ing movements of Whistling Swans. When the swan dips its head to dig for 

 sago tubers, ducks swim over to rob the gleanings. Canvasbacks and Red- 

 heads often join feeding Lesser Scaup ; Pintails join Mallards. 



The reply to a signal, whether vocal or active, is often immediate — as 

 sharp, almost, as the response of the electric light to the turn of a switch. 

 This is especially true of situations related to reproduction or to survival, 

 where instant reaction is the key to life. All social communication, however, 

 is not limited to the sharp response. Every action of an individual or group 

 identifies its behavior to other members of the society. Since it is easier for 

 members of a social group to do things at the same time, every action is a 

 cue or signal, and the behavior of the individual is repeated by the crowd. 

 If a duck had a creed it would be: Do as others do; go where others go. 

 When one bird happens on a choice bed of food, it is easier for the group 

 to feed there than for each member to seek out its own special plot. When 

 one of a band of Lesser Scaups begins to dive busily over a sago bed it has 

 just located, its lead is the signal for companions to come hither and feed 

 in the same place. When one small party finds a safe loafing bar, the locality 

 soon is the resting place of many. In any social gathering of waterfowl the 

 members do the same things at the same places at the same times. In old 

 birds this may be merely a matter of convenience; in ducklings, the very 

 survival of the individual hinges on co-ordinating its behavior with that of 

 its companions. A bird thus learns by following the actions of others more 

 experienced. 



A striking example of group behavior is seen when a gathering is con- 

 fronted by an entirely new situation. In late April, when Lesser Scaups 

 litter the bay in their many hundreds, they depart quickly from the edge in 

 escape movements when I walk boldly to the shore. But when I sneak 

 through the tules unseen, then remove my plaid shirt to wave it above my 



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