MEXICAN DIPPER 113 



is found in Alaska, Canada, and the United States ; the third race is 

 found in Guatemala. 



Casual records. — An individual was watched closely in May 1891, 

 on the Wliite Kiver, Sioux County, Nebr. ; and a specimen was collected 

 June 2, 1903, at Wauneta, Chase County, Nebr. 



Egg dates. — Alberta : 8 records, April 14 to June 28. 



California : 30 records, March 23 to June 26 ; 16 records, April 18 

 to May 20, indicating the height of the season. 



Colorado : 20 records, April 4 to June 10 ; 10 records, May 9 to May 

 31. 



Oregon : 6 records, April 18 to June 7. 



CINCLUS MEXICANUS MEXICANUS Swainson 

 MEXICAN DIPPER 



Discovery in the Field Museum in Chicago by Emmet R. Blake 

 (1942) of a specimen of this type race of the species, collected by 

 George F. Breninger in the Huachuca Mountains, Ariz., on May 28, 

 1903, entitles this form to a place on our list. Until recently our 

 North American form, G. in. vmicolor^ was supposed to extend its range 

 in the mountains of California, Arizona, and New Mexico approxi- 

 mately to the Mexican border. Evidently these, and other extreme 

 southern mountain ranges, have also attracted several other Mexican 

 forms, as they lie close to the border and have formed a natural path- 

 way into the United States. 



The Mexican dipper is darker than our more northern bird; its 

 head and neck are deep sepia brown, whereas in our northern bird 

 the head and neck are more grayish brown, and the whole plumage 

 is paler. 



Family TROGLODYTIDAE : Wrens 



TROGLODYTES AfiDON AEDON Vieillot 



EASTERN HOUSE WREN 



Plates 25-27 



CONTElBtJTED BY ALFRED OtTO GROSS 

 HABITS 



There are two recognized forms of the house wren, the eastern, 

 Troglodytes dedon aedon^ and the western. Troglodytes aedon park- 

 manii. Oberholser (1934) in a revision of the North American wrens 

 has adopted Wilson's name domestica because it "seems" to antedate 

 Vieillot's name aedon by which the bird has long been known. The 

 less rufescent birds inhabiting the region from Michigan, Indiana, 

 Kentucky to West Virginia, western Pennsylvania, western New York, 



