OLD CROW 223 



which demonstrates that they are developed through long experience 

 of the population and repeated through the operation of memory. 

 These are quite different influences from the current impulses ap- 

 parently directing movements of waxwings without known directional 

 regulation. 



Family LANIIDAE: Shrikes 



Lanius excubitor Linnaeus 



On April 16 a shrike lit in the top of the willows along the river 

 and after a few short flights from our pursuit disappeared among 

 the willows on the island just above the village. 



Joe Kay recognized the illustration of a shrike and gave the name 

 Tsi kwut go katsliilyi, which he said referred to the shrike's habit of 

 hanging its prey on bushes. No other shrike was seen. Above the 

 timber on the mountains we did not find the situations in extensive 

 willow-filled valleys where shrikes are rather common in spring and 

 summer in central arctic Alaska^ 



Family PARULIDAE: Wood Warblers 



Four of the wood warblers at Old Crow are assigned to races which 

 extend far eastward from Yukon. Vermivora celata celata^ Den- 

 droica petechia amnicola, and D. striata nest across northern 

 Yukon and Alaska, while Wilsonia fusilla pusilla is replaced by 

 W. p. pileolaia at AjQaktuvuk. V. c. celata, D. p. amnicola, and D. s. 

 lurida seem to be confined to the northern part of Yukon. This area 

 serves as an arctic bridge connecting the Canadian and Alaskan 

 populations, which extend to the northern limit of forest. 



It is difficult to decide whether the water thrushes from Old Crow 

 are Seiurus novehoracensis notdbilis or S. n.i limnaeics. If they are 

 notabilis they should be counted as eastern warblers, if limnaeus they 

 are of a western race, as is clearly the Old Crow D. c. hooveri. The 

 western races of warblers extend farther south in Alaska and Yukon 

 than do the four eastern races. 



It is not yet clear whether the eastern races of warblers migrate to 

 Alaska along the Porcupine Valley, where they nest, or through 

 southern Yukon, where the migrating races have not been clearly 

 separated. In fact better identifications and range determinations 

 of warblers in Alaska and Yukon will give significance to what now 

 appear to be peculiar distributions. 



I am particularly indebted to Bernard Feinstein of the tJ. S, Na- 

 tional Museum for his help in making the comparisons by means of 

 which the wood warblers are identified. 



