164 BULLETIN 19 7, UNITED STATES NATIONAL MUSEUM 



ground. Where possible the nests are hidden below the crown of the 

 bush or tree and are placed on limbs that afford ample support for 

 the comparatively heavy structure. The use of old nests as founda- 

 tions for building new structures frequently is recorded. I have ob- 

 served this in at least five nests of gambeli. 



Nests have been found by me in live oaks, willows, various orchard 

 trees, cypress, sumac, saltbush, blackberry vines, acacias, peppertrees, 

 and eucalyptus trees. The greatest height at which a nest has been 

 noted is 30 feet from the ground in the top of an acacia. Bancroft 

 informs me of the nesting of this race in loose tangles of baling wire 

 about 4 feet high and 6 feet long, Grinnell (1911) records an in- 

 stance in comparatively barren terrain of nesting between two upright 

 boards of a support for telephone wires. 



The materials used in building the nests are extremely varied and 

 dependent on local supply. Shrike nests commonly have an ample 

 substructure of twigs, usually not more than one-quarter of an inch 

 in diameter. Occasionally the nest is a more or less homogeneous cup 

 lacking a base of sticks. Grass is seldom used extensively, but stalks 

 of various annuals are employed, often taking the place of sticks or 

 twigs. The lining ordinarily is heavy, forming a thick felted cup with 

 a wide margin, which frequently projects outward a distance of an 

 inch over the stick framework. The lining includes cottonlike sub- 

 stances principally, with smaller amounts of hair, feathers, rootlets, 

 and bark. The lining is especially variable according to the local 

 supply of materials. In sheep country much use is made of wool. 



Wide variation occurs even in nests from the same vicinity. A fe- 

 male of a pair at Pinole built an extremely inferior type of nest early 

 in the spring of 1930. The framework was of small twigs and rootlets, 

 rarely over 2 millimeters in diameter, which basal structure extended 

 not more than 1 inch beyond the narrow rim of the nest cup. The lin- 

 ing was not over one-quarter of an inch in thickness and was com- 

 posed of willow catkins, hair, and a few strips of bark. Likewise, the 

 nest cup was unusually small, barely 3 inches in diameter and 2 inches 

 deep. A second nest of the same sort was built by this pair, which 

 was only slightly more substantial than the first. The first nest had 

 become dislodged from its precarious position among the small twigs 

 of a willow and had allowed the small young to fall to the ground. In 

 contrast to the efforts of this pair was the series of three nests built 

 by another female, each of which was lined to the extent of nearly an 

 inch in thickness. The cups of these nests were 4 inches across, and 

 the maximum diameter of the entire substructure of one of the nests 

 was 12 inches. 



Nests may be situated well braced in crotches of large limbs, against 

 boards or other artificial supports, or among the fine dense twigs of 

 bushes, trees, and vines. The desirability of large limbs as supports 



