30 U.S. NATIONAL MUSEUM BULLETIN 23 7 pabt i 



Additional observations are furnished by Gould (1961) from bis 

 research in the Tucson area. He writes: 



Nest building is apparently carried out primarily by the females of both species. 

 Observations on one Cardinal and one Pyrrhuloxia nest under construction 

 showed only the females building, while the males stayed far back in the trees 

 singing. Most nest material, with only one observed exception, was gathered 

 within the established territory. I never saw material gathered within the 

 territory of another pair. 



* * * 



Egg laying may occur any time in the months of May, June, July, and early 

 August * * *. The most active period for both species was the first two weeks 

 in June. Pairs found nesting in August had probably been unsuccessful in earlier 

 nestings. Clutch size of the cardinal varied from two to four eggs and averaged 

 three. Clutch size of the Pyrrhuloxia varied between two and three eggs, both 

 numbers being equally common. 



Nests have been observed in mesquites, catclaw, and condalia 

 bushes at heights from 5/^ to 7 feet above the ground. When placed 

 in the dense leafless mistletoe {Phoradendron calijornicum) common 

 to desert leguminous shrubs, there is a measure of concealment. 

 Mrs. Bailey (1928) says that in New Mexico, the nest is placed "in 

 mesquite and thorny bushes," is "small and compactly built of twigs, 

 inner bark, or coarse grass, lined with a few rootlets or fine grass and 

 fibers." Brandt (1951) gives us more detail: "Nest situated b)i feet 

 up in a bushy mesquite shrub of many boles ; a gray affair, made of a 

 variety of weed stems and some cobwebs, but no large leaves or pepper 

 grass as used by Cardinal; lining of pale brown rootlets; nest neat, 

 small, compact, with well made rim. Measurements, height, 3.50; 

 width, 4 by 4.25; bowl depth, 2; bowl width, 2.25 by 2.50 inches. 

 Contents, 3 eggs, incubation 4 days." 



Gould (1961) found that: 



Nests and nest sites of the species were very similar. Eight Cardinal and 20 

 Pyrrhuloxia nests ranged between 5 and 15 feet above the ground, both aver- 

 aging 8 feet. In the study area both preferred to nest either in mesquite or gray- 

 thorn. One nest of the pyrrhuloxia was found in an elderberry. In other areas 

 around Tucson, Cardinals were found to use tamarisk (Tamarix) trees, and 

 Pyrrhuloxia nests were not uncommon in palo verde (Cercidium). Both species 

 seemed to prefer thick patches of brush or dense hedgerows; however, of the two 

 species, the Pyrrhuloxia utilized more open situations. Cardinals were much 

 more apt to place their nest against a major trunk of a tree than were Pyrrhuloxias, 

 but both usually placed it in the small twigs that occur on the secondary branches. 

 Neither species anchored the nest securely to the twigs or branch on which it was 

 placed. * * * 



The nest of the Pyrrhuloxia was almost always constructed of dead material. 

 Of 20 nests only one contained green material, and this amounted to only a few 

 mesquite leaves that had been added to the outside. The nature of the material 

 often gives the nest a very decidedly grayish appearance with brownish high- 

 lights. The cup was usually well lined with rootlets, and occasionally thin 

 strips of bark, horse hairs, or very small plant stems and fibers were used. The 



