AWARENESS OF DIRECTION 



Such assumptions are often embellished with the suggestion that the 

 young bird went with precision to this place. If the wintering area has been 

 used by a particular species for many years, or if the adults have arrived 

 earlier, some by a different route, these circumstances are given as further 

 evidence that the tie between bird and place is innate. Science has yet to 

 describe an inborn awareness of a proximate geographic location, and it 

 seems unreasonable to believe that such an awareness exists for some dis- 

 tant place beyond the realm of experience. A female may have an inborn 

 urge to nest in a rather narrow ecological pattern of environment; but each 

 and every female must explore to find the geographic place of her nest. 

 In the same way young waterfowl and juveniles of many other species ap- 

 parently have an innate awareness of environmental patterns, but the exact 

 locations of these places they use their first autumn and winter must be 

 found in the course of their juvenile explorations. 



Some young ducks reach the wintering range in their primary wander- 

 ings, getting there before many adults have arrived. Other vagabonds, 

 at the same time, find their way north or east or west. As long as these 

 youngsters have no experience of the land over which they wander, they 

 are under certain environmental influences. By their innate response to 

 water, the early movements carry the young ducks from one lake or marsh 

 to another. They follow rivers and shorelines ; and when they move over- 

 land, their stopping places are marshes and lakes. In this random travel 

 the wind inevitably is a major influence on the pattern of their wanderings. 

 Without geographic goals the over-all trend of nomadic flight will be in 

 the direction of the air flow, and it is most important that we understand 

 the relation of the wind to the wandering juvenile. When a bird, young 

 or old, moves about on its familiar range, flying to and from familiar ob- 

 jectives, the wind modifies the timing but not the direction of these move- 

 carried out which have produced results accepted by some as evidence of an inborn awareness 

 of the direction of autumn migration. In several of these studies, pure groups of young birds 

 were used, but there was no analysis of the weather prevailing during the period of study. 

 Others studied the weather, but could not rule out the possibility of young meeting experienced 

 adults. Nor has the role of tradition been thoroughly examined, as where local birds moved by 

 tradition, while the experimentals, released later, might have been influenced by major air mass 

 flow. When we assume something so vastly fundamental as genetic influence on geographic 

 direction, I believe experimental investigations must insist on: (1) Studies to be carried out 

 only with birds in which the history is known from birth. (2) A thorough assay of "ecological 

 factors in the broadest sense, including air mass characteristics, wind direction, the apparent 

 structure assumed by convection currents in the air, ocean currents, ocean wave patterns and 

 the possibility that the sun or resulting sky-brightness pattern could serve as a directional cue" 

 (Griffin and Hock, 1949:196). (3) No opportunity for experimental birds to join experienced 

 wild companions. ( 4 ) A study of the role of tradition in the migration of the wild stock against 

 which the experiments are being compared. 



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