Page:CooperBull1(4).djvu/6

 BULLETIN OF THE COOPER ORNITHOLOGICAL CLUB. 6 3 wide apart; some are long, either oval or pointed at one end, seldom pointed however, while others are much round- ed. The difference in size and shape of eggs in one set is occasionally com- mentable and the style of marking may be odd, also the ground color, while very rarely all these characteristics pre- sent themselves in a set of four eggs. Four eggs is the average number to a set, often three, and only twice have I found five eggs. I have taken two sets of two eggs each, all much below med- ium size; three eggs were well incuba- ted and the fourth was infertile. In early numbers of the zVidioloffist I referred to having found sets of unusu- ally stnall eggs, and individual birds laying successive sets of such eggs. The only abnornmlly large egg I found was among a set of three eggs. One nest of four very small eggs contained two that were infertile, two heavily in- cubated and two of the California Par- tridge, heavily incubated. The nests bear a great similarity in material used. The general composi- tion is a lot of dry leaves for a founda- tion or for a lining over the earth, strips of bark, stalks of weeds, coarse dry grass, occasionally a few shavings and rubbish that can be worked into the foundation and rim. The lining is the least variable, being neatly laid, rather crosswise, and consists of a certain kind of fine, bright, dry grass which is al- most all stem. Occasionally'there is a little less of this grass when long hair is substituted, but this they seem unable to place so neatly as the California Towhee. A nest under an oak in the center of a large grain field was com- posed of a' few pieces of weed stems, the balance and the lining' of short, rather coarse black rootlets, the wild grass in this ease being probably too far distant for birds of short flight to carry. A nest built near a pile of dead cypress branches was com- posed chiefly of strips of bark from the branches. Other nests when- ever found under pine trees are invar- iably lined totally with dry pine need- les, the birds evidently preferring this pliant material of suitable length to the kind of grass usually used and growing dose by. The young when first hatched are t black with yellow gapes and covered with thin greyish-white down. The J incubating bird sets dose and the nest,/ is usually found by flushing the bird which at times flushes at the sound of approach fifty feet away, always be- traying the location by rising high e- nough into the air to be detected, though occasionally slipping away through cover to a short distance, only to make a fuss and cause a search for the nest. At times the bird hops along a few feet before rising. Some years ago, one winter, I beheld an Oregon Towhee on top of a leafless apple tree truthfully imitating the Cal- ifornia Jay's eommonest notes, very dif- ferent from its own. From my dose point of observation I could detect the movements of its throat and bill and de- termine that none other than the object of my gaze was for the time being thd "mockingbird", the only one of its kind I have had the fortune to hear. Summer Resident Warblers of Arizona. BY O. W. HOWARD, LOS ANGI,LF.S, CAL* [Read belbre the Southern Division of the Cooper Orn. Club, Feb. 25, 899. ] VIRGINIA'S WARBLER. (Cwtcluded.) This species is quite common in the pine regions throughout Arizona, but I have not seen it at a lower elevation than 5ooo feet. Unlike other warblers in this section, they keep almost entire- ly in the underbrush, where ttrey are continually on the move and at the same time uttering a quick chirp as if in distress. Owing to the dull plumage and retiring habits of this bird compar- atively few are seen. The nests are placed on the gr9und, under a Bush or tuft of grass and are made of fine' straws, rootlets and fibres, loosely put together. Except when the birds have young, they are very shy about going to the nest, and for this reason few nests are found with eggs while more are found containing young birds.