24 



THE OOLOGIST. 



Excubitorides or Migrans? 



For several years I have been much 

 interested as to the identity of- the 

 small grey shrikes that inhabit Fulton 

 Co., N. Y., during the summer months. 

 For a long time I believed the species 

 to be the common White-rumped 

 Shrike, lanius ludovicianus excubi- 

 torides, and as such I mentioned the 

 species in the Oologist for December, 

 1903. 



Later on I reviewed my data on the 

 subject, and in 1906 began to think 

 that the species, migrans. Such was 

 the name in "Some 1906 Notes," pub- 

 lished in this paper for December, 

 1907, and it was the query, inserted 

 by friend Short "Was not this excubi- 

 torides?" that has led to the publi- 

 cation of this article. 



I insert a description of our Fulton 

 county Shrike, taken from a freshly 

 killed specimen: Length, 8.81 in.; ex- 

 tent, 12.63 in.; wing, 3.69 in.; tail, 

 3.56 in.; hill, culmen, 63 in.; tomia, 

 .91 in.; gonys, .44 in.; tarsus, .94 in. 

 Upper mandible of the hill dark grey, 

 lower mandible greyish black; irides, 

 olive brown, tarsus and toes grayish- 

 brown. Forehead, crown, nape, back, 

 rump, and upper tail coverts slaty- 

 gray, tinged more or less with brown 

 throughout, tail graduated, outer rec- 

 trix almost entirely white; the re- 

 mained with more black as they ap- 

 proach the central pair, the fourth 

 and fifth pairs being black with only 

 the extreme tips of the feathers 

 whitish; the central pair uniform 

 dark brownish black; auriculars, orbi- 

 tal and loral region, and nasal tufts 

 black; chin, throat and entire under 

 parts, white, tinged on the bi-east 

 with grayish brown, scapulars gray- 

 ish white ; lesser coverts gray ; mid- 

 dle and greater coverts glossy black; 

 primaries medium brown with basal 

 third and vane of the feather, pure 

 white; secondaries of brownish black 



with extreme tips of feathers slightly 

 lighter. Sex, fm., Mayfield, Fulton Co., 

 New York, Aug. 2, 1907." 



Now it is observable at once that 

 this bird is not the typical subspecies 

 ludovicianus, Linn., because our bird 

 has the tail slightly shorter than the 

 wing instead of the reverse, while the 

 bill appears to average slightly small- 

 er. Ridgway gives the range of ludo- 

 vicianus as follows: "Southern Unit- 

 ed Stated. Coast district of South 

 Carolina and Georgia to southern 

 Florida, west over the coastal plain of 

 the United States to Louisiana." 



Returning to excubitorides Swain- 

 son, we find that our Shrike agrees in 

 having the tail shorter than the wing,, 

 but lacks entirely the sudden change 

 of color of the uropygius and upper 

 tail coverts (whense, indeed, the com- 

 mon name of white-runged Shrike.) 

 mon name of white-rumped Shrike.) 

 preciably different, in color, from the 

 back. 



The range of excubitorides, is giv- 

 en by Ridgway (Birds of Middle and 

 North America; Volume III) as fol- 

 lows: "Arid district of western Unit- 

 ed tSates and British Provinces, from 

 the eastern border of the Great 

 Plains to the western margin of the 

 Great Basin." 



The new variety, migrans. Palmer, 

 was first described in the "Auk" in 

 1898. It is distinguished from th^ 

 other twoc ommon Shrikes by the 

 characteristics mentioned above, as 

 well as by having the under part& 

 usually less purely white than the 

 other sub-species. This character in 

 our Shrike is very pronounced, the 

 breast and belly 'being strongly ting- 

 ed with grayish brown. The range of 

 this sub-species fills in the vacancy 

 left by the other varieties, being as 

 follows: "Greater part of the United 

 States east of the Great Plains', hut 

 very local in the more eastern dis- 

 tricts." 



