Vol. XXI 

 1904 



I Clark, Curved-billed a7id Palmer'' s Thrashers. 21^ 



any one who may have notes on these birds further north to com- 

 pare them with the following. 



Although these localities are separated by over eight hundred 

 miles, the climate is the same and the country looks the same ; in 

 both cases we have a few mountains between which lie immense 

 mesas and valleys which are mostly timberless and waterless, but 

 covered with a curious growth of cacti in which the birds nest. 

 The cacti of each place are different with the exception of the 

 cholla, which is common in both places, and singularly enough it 

 is the most common nesting site. 



The new nest of both birds is generally near the old one, usually 

 in the same cactus, and sometimes the old nest made over. 



Sometimes the nest is completed two or three weeks before the 

 eggs are laid. Then again, if the nest and eggs are taken the 

 birds will have another nest and eggs in from twelve to fifteen 

 days, and the new nest is usually about fifty feet from the one 

 taken, but if the first nest is not disturbed the new nest will usu- 

 ally be about five feet from the old one. 



The nests of both birds are the same, made of thorny twigs; 

 in fact, nothing grows there without thorns on it, so they can get 

 nothing else. These sticks are six to ten inches long, and form 

 the outside of the nest, which is lined with wire grasses ; some- 

 times horse hair is used in place of the grass, or with it. The 

 nests are externally about ten inches in diameter and eight inches 

 deep ; internally about three and one-half inches, both in diameter 

 and depth. 



These birds are common permanent residents of these respec- 

 tive places and may be seen in pairs throughout the year, using 

 their old nest for a roost. 



The following sets do not represent average sets, but I have 

 selected them to show the range in measurements. 



Following are the measurements in millimeters of ten sets of 

 the Curved-billed Thrasher. 



Set No. 6 30.95 X 19.05 30.83 X 19-05 29.45 X 19.20 



" 9 29.81 X 19.00 29.05 X 19.52 28.03 X 19.75 



" 27 29.80X19-45 29.30X19.65 28.40X19.33 



" 57 28.29X19.45 27.95X19-46 27.48X19-71 



" 4 33-50X21.08 32.12X21.54 



