28 BIRDS OF THE PAP AGO SAGUARO NATIONAL MONUMENT. 



semblance, however, there is little likelihood of the Palmer and 

 crissal thrashers being confused, for the two birds inhabit different 

 types of country. The Palmer thrasher is a denizen of the open, 

 cactus-covered mesa; the crissal thrasher frequents the mesquite 

 thickets of the river beds. 



To distinguish between the Palmer and Bendire thrashers is an- 

 other matter, for the two are found in exactly the same surround- 

 ings and resemble each other closely in appearance. The Bendire 

 thrasher is the smaller of the two, perhaps an inch shorter in 

 length, is more definitely spotted on the breast, and has a shorter, 

 less curved bill. It is known to occur about Phoenix, but I did not 

 meet with the species, and it is certainly far less abundant than its 

 larger relative. 



The Palmer thrasher is resident the year through in Arizona. 

 Nest building begins before winter is fairly over, and the first eggs 

 are laid late in February or early in March. Sets of eggs may be 

 found until about the middle of May. The usual number of eggs in 

 a set is three, rarely two or four ; in color the eggs are pale bluish- 

 green, uniformly dotted with brownish. 



The nesting habits of the Palmer thrasher have been described in 

 detail by Brown, 1 from the region about Tucson, and by Oilman, 2 

 from Sacaton. The latter makes the following statement : 



The Palmer thrasher (Toxostoma curvirostre palmeri) showed a decided 

 preference for the cholla cactus as a nesting site. Of 27 nests found, 11 were 

 in the cholla ; 7 in the jujube, about as spiny as any cactus ; 4 were in mistletoe 

 of mesquite and cottonwood ; 2 in Lycium ; 2 in mesquite ; and 1 in a clematis 

 vine trailing over a shrub. The average distance from the ground was 6 feet, 

 and extremes were 2J feet and 10 feet. * * * Fourteen of the 27 nests con- 

 tained 3 eggs each ; 2 had 4 eggs ; and the rest 2 and 1, some of the complete sets 

 being 2 eggs. 



The human investigator can only marvel at the manner in which 

 the cholla cactus is utilized. It is a plant to be approached gin- 

 gerly always, handled never, yet the birds slip through the inter- 

 laced arms with their fiendish array of thorns without hindrance 

 or injury. Not only the thrasher, but the cactus wren also, habit- 

 ually build nests therein; while other birds (the mourning dove 

 frequently, and even the desert quail at times) utilize last year's 

 thrasher and wren nests, crushed flat, on which to lay their eggs. 



The manner in which the desert wood rat uses the cactus in barri- 

 cading his home is another story, but one sure to be drawn to the 

 attention of the student of desert birds. The marvel of it is that the 

 cactus, while an effective barrier against enemies, should be traveled 

 over and handled with impunity by the animals seeking protection. 



1 Zoe, III, October, 1892, pp. 243-248. 



2 Condor, XI, March, 1909, pp. 49-54. 



