WESTERN ROBIN 55 



were fairly alive with them. Others were seen flying about in loose 

 flocks and were probably migrants. 



Nesting. — The nesting habits of the western robin are, in the main, 

 very similar to those of its eastern relative. The nest may be placed 

 anywhere from on the ground up to 75 feet in a tree, in bushes or in 

 trees of many kinds, but most of the nests are not over 12 feet above 

 the ground. Nests on structures erected by human beings seem to be 

 less common than with the eastern bird. They are usually typical 

 robin nests, made of the usual materials, including a liberal supply of 

 mud, and firmly built. Mr. Rathbun (MS.) describes a poorly con- 

 structed nest that "was placed at a moderate height in the fork of a 

 young alder, this crotch being filled with fresh leaves of the vanillaleaf 

 (Achlys triphylla), with which were a few twigs. Next was a thin 

 coating of mud, and its lining was an abundance of green grasses and 

 a few dried ones. Very little skill was shown in the construction of 

 this nest, my attention being attracted to it simply by seeing a mass 

 of green leaves piled in the fork." Mrs. Wheelock (1904) says that 

 the nests that she has "found have been somewhat different from 

 those of the Eastern bird and very much prettier, being decorated 

 with moss woven in the mud instead of straw, and carefully lined with 

 moss. It is really a beautiful structure, with the mud practically 

 concealed from view." 



Dr. Walter P. Taylor (1912) says that, in northern Nevada, "nests 

 were found on the ground and at various heights up to six feet above 

 it, and were located in willow thickets, wild-rose bushes, sage-brush, 

 quaking aspens, poplars (at Big Creek Ranch) and limber pines." 

 Various other species of pines, spruces, and firs, as well as a variety 

 of deciduous trees, have been occupied as nesting sites in other sections. 



Joseph Mailliard (1930) had an opportunity to watch all the hap- 

 penings at a robin's nest within 10 feet of his office window and pub- 

 lished a full account of what took place from the building of the nest 

 until the young left, to which the reader is referred. The nest was 

 built in six days. 



Eggs. — The western robin is said to lay three to six eggs; three 

 seems to be a commoner number than four, and the larger numbers 

 are very rare. The eggs are indistinguishable from those of the eas- 

 tern robin. The measurements of 40 eggs in the United States 

 National Museum average 29.2 by 20.7 millimeters; the eggs showing 

 the four extremes measure 32.5 by 20.3, 30.9 by 22.4, and 23.4 by 

 17.3 millimeters. 



Young. — In the nest watched by Air. Mailliard (1930) incubation 

 was performed entirely by the female; this lasted for 14 days, during 

 which time she left the nest only occasionally for 15 or 20 minutes 



