TRADITIONS OF WATERFOWL 



(1944) discusses the role of tradition in the feeding habits of birds and 

 comes to the conclusion "that all evidence so far available favors the con- 

 tention that the differences in specific food habits of various species of 

 raptors are maintained much more through non-heritable factors passed on 

 by the interaction of parental behavior with that of the offspring than they 

 are through specifically heritable factors." He goes on to say that "there 

 is abundant evidence that tradition may play an important role in the food 

 habits of a great variety of birds besides raptors." 



When a wild bird feeds on a cultivated domestic crop, there must be 

 some link of tradition that carries this new food habit from one generation 

 to the next. In the Mallard and Pintail, the habit of eating cereal grains 

 is certainly traditional, and this likewise holds for ducks that feed on let- 

 tuce fields in the Far West or on rice in the southland. More obviously 

 traditional, perhaps, is the acquired habit of opening milk bottles in the 

 Great Tit and at least ten other British birds. Fisher and Hinde (1949) 

 show how this milk-robbing has "become widespread in many parts of Eng- 

 land and some parts of Wales, Scotland, and even Ireland." These authors 

 concluded, after careful study, that "this source of food was actually dis- 

 covered de novo by only a small proportion of the tit population, and was 

 then passed on in some manner to other individuals." In such feeding tradi- 

 tions pioneers discover new sources of food by trial-and-error learning, per- 

 haps as some human beings first learned to relish tomatoes. Companions 

 eventually repeat their actions until the habit is acquired by many. Miller 

 (1942) says that "habits and associations with respect to environment and 

 particular landmarks are passed on nongenetically from generation to gen- 

 eration. Cultures or societies are formed in the higher vertebrates, as indeed 

 in humans, and temporary barriers set up. Perhaps the hill-dwelling Song 

 Sparrows of San Francisco Bay do not associate with those of the salt flats, 

 figuratively and literally on the other side of the railway tracks, because 

 of their upbringing." Snyder (1948), who discussed avian traditions in 

 some detail, shows how a transplanted population of Mallards established 

 a traditional breeding area in Ontario. Lorenz (1952), speaking of his be- 

 loved Jackdaws at Altenberg, tells how the modern birds "follow loyally all 

 the traditions which reigned in the first colony, and which were trans- 

 mitted to the present by Redgold." 



Mayr (1942:53) speaks of the Yellow Wagtail of Europe, which "is 

 nearly always a ground-nesting bird. About 1915 Schiermann (1939) found 

 a little colony of these birds in which all individuals (eight or nine pairs) 



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