MIGRATIONS OF WATERFOWL 



tions of visibility. And of course the great waves of misplaced birds, as re- 

 ported by Williamson ( 1952 ) , make it clear that migrants cannot invariably 

 hold a track throughout a journey in bad weather. 



Banding records demonstrate that birds come back again and again to 

 the same stopping places and winter destinations every year; and we gather 

 that migrants are familiar with these regions of annual return. But it must 

 not be assumed that every bird homing in spring flies every mile of the 

 way by retracing a route learned in the fall. Like Pintails going south via 

 California and homing north through the Mississippi Valley, or ducks flying 

 part of the way over cloud, or birds of many kinds blown far off course by 

 unseasonable wind, or migrants obliged to cross vast stretches of open 

 water, there are many individuals which annually must rely on an aware- 

 ness of the direction home for at least a part of spring migration. In short, 

 Type III navigation, where the traveler in strange surroundings perceives 

 the direction toward home, must be fundamental in spring migration. Such 

 homeward awareness in strange regions has been observed with many 

 kinds of birds released under experimental conditions: Noddy and Sooty 

 Tern (Watson and Lashley, 1915), Swallow (Wodzicki and Wojtusiak, 

 1934), Song Sparrow (Manwell, 1936), Alpine Swift (Schifferli, 1942), 

 Homing Pigeon (Matthews, 1951a; Griffin, 1952b; Hitchcock, 1952; Kramer, 

 1952), Herring Gull, Lesser Black-backed Gull, and Manx Shearwater 

 (Matthews, 1952, 1953a). 



With Swallows, Wodzicki and Wojtusiak (Wojtusiak, 1949) found that 

 in many of their experiments "there was noticeable a characteristic be- 

 havior of the birds at the moment of their release. The Swallows soared 

 up into the air, described one circle or several, and then started to fly in 

 a direct line toward their nesting site." Griffin's pigeons, when released at 

 points 72 and 100 miles from their loft, "took the correct initial direction 

 within two miles of the release point." Kramer (1952:284), after studying 

 the direct homing of his pigeons, concluded that "some sort of astronomical 

 navigation is suggested by the fact that the pigeons seem to be orientated 

 even before starting." Matthews (1955b: 94) found that this initial orienta- 

 tion* toward home functioned only when the sun was in view: the "home- 

 ward orientation shown by pigeons in critical releases in sunny weather 

 deteriorates markedly in conditions of heavy cloud and breaks down com- 



• "Initial orientation" is that observed at the point of release. Not all individuals making 

 initial orientation homeward have equal success in reaching home. See Matthews (1955b: 26) 

 for a summary of homing success. 



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