162 U. S. NATIONAL MUSEUM BULLETIN 211 



southern Manitoba (Brandon), northern and central Minnesota 

 (Hennepin County), northeastern Illinois (Waukegan), southeastern 

 Michigan (Erie), southern Ontario (Brankford), central Ohio (Licking 

 County) and western West Virginia (Mason County); regularly south 

 to north-central Colorado (Semper), central Texas (Boerne, Edge), 

 and Louisiana (Belcher, Jefferson Parish). 



Casual records. — Casual in southeastern Alaska (Mole Harbor, 

 Sergief Island), central Yukon (Mayo Landing), west-central British 

 Columbia (Kispiox Valley), northern Manitoba (Churchill), extreme 

 northeastern Ontario (Cape Henrietta Maria), central New York 

 (Cayuga and Tompkins Counties), Connecticut (North Haven), and 

 Georgia (Tifton). 



Accidental in northern Alaska (Cape Price of Wales, Barrow) and 

 northern Mackenzie (headwaters of the Dease River). 



AGELAIUS PHOENICEUS FORTIS Ridgway 



Thick-Billed Redwing 

 HABITS 



The thick-billed redwing seems to be very closely related to the 

 giant redwing and so much like it in measurements that Ridgway 

 (1902) did not separate the two forms. He called fortis the northern 

 redwing and assigned to it the far northern range of the bird we now 

 call arctolegus. Both of these two forms are about the same size, 

 considerably larger than the eastern redwing, and both have thick 

 bills, as mentioned under the preceeding race. 



The thick-billed redwing, as it is now understood, breeds from 

 Idaho, Wyoming, and South Dakota to Colorado and northern Texas. 

 Its breeding range extends well into the foothills of the Rocky Moun- 

 tains, where it has been detected at elevations of 7,500 and 9,000 feet 

 in Colorado. 



Young. — At an Iowa nest of the redwing, evidently of this race, 

 Dr. Ira N. Gabrielson (1915) made the following observations on the 

 female feeding the young: 



Altogether during the 170 feeding visits she brought 203 morsels of food. Of 

 these, grasshoppers were 34.97%, moths 9.37%, larvae 9.35%, unidentified 17.24%, 

 and the remaining 29.09% was composed of various insects. The unidentified 

 were mostly small insects captured among the arrowhead lilies but we could not 

 identify them. A very small frog was fed on one visit. As far as numbers were 

 concerned the distribution of food to the nestlings was very equal, A receiving 

 34.97% of the insects fed, B, 32.51%, and C, 31.51%. It is not so easy to esti- 

 mate the percentage by bulk on account of the varying sizes of the insects 

 fed. * * * 



The position of the blind and the surrounding vegetation exposed the nest 



