338 DAVENPORT ACADEMY OF SCIENCES. 



Famib' LANIID^. Shrikes. 



The Shrikes or Butcher Birds are passerine birds with hawk- 

 like prodivities, pre3dng chiefly upon mice, small birds, and in- 

 sects, which they have the habit of impaling upon thorns, sharp 

 twigs or barb- wire fences. Their clearl}^ massed colors of black, 

 white and cadet gray render them easily distinguishable. 



Genus Lanius Linnaeus. 



27S. (621). Lanius. borealis Y'lexW. Northern Shrike. 



The Northern Shrike is a common winter resident in all parts 

 of the state. It usually appears during the latter part of Octo- 

 ber and remains until March, having been observed as early as 

 October 20 and as late as April 3. The English Sparrow is fre- 

 quently captured by the Northern Shrike, but Tree Sparrows and 

 J uncos are also destro3'ed. H.J. Giddings has noticed them fre- 

 quently on the ground picking up insects, and once during a warm 

 spell in February saw one catching large insects on the wing, cap- 

 turing twenty-five in the short time that he watched it. This 

 species frequently enters towns in winter in pursuit of Sparrows 

 and seem to be quite fearless. 



279. (622a). Lanius hidovicia?ius cxacdiforides (Swains.). White- 

 rumped Shrike. 



The status of the two summer-resident forms of Shrikes in 

 Iowa is an unsettled question. Most recorders refer to the breed- 

 ing birds as White-rumped and Loggerhead Shrikes rather in- 

 discriminately, and the records are therefore of doubtful value. 



Ridgway (Bds. N. and Mid. Amer., iii, p. 246) describes excubi- 

 torides as "similar to L. I. migrans, but gray of upper parts 

 decidedly paler; changing abruptly to white on upper tail cov- 

 erts; white of scapulars more extended (occupying practically 

 the whole of scapular region) and more abruptly contrasted with 

 .gray of back ; forehead and supraloral region paler gray than 

 crown, sometimes whitish; under parts pure white; size averag- 

 ing slightly larger." 



T. M. Trippe (Am. Nat., 1873, p. 497), writing before the form 

 L. I. migrans was elaborated, states: " In a residence of two 

 years in central and southern Iowa (Decatur and Mahaska coun- 

 ties) I killed a large number of Shrikes, and although the larger 



