AMERICAN MAGPIE 139 



Concerning the time of egg laying, Kalmbach (1927) writes that "in 

 Colorado, Utah, California, and southern Oregon, egg laying begins 

 before the middle of April, in Washington and Montana about two 

 weeks later, while in the extreme northern part of the magpie's range 

 it does not begin before June or even July." 



Coloration of the eggs varies, but the ground color is usually greenish 

 gray, and this is profusely blotched with different shades of brown, 

 sometimes completely hiding the ground color. Bendire (1895) de- 

 scribes the majority of the eggs as ovate. Others are short-ovate, 

 rounded, elliptical, and elongate-ovate. The shells are close grained 

 and moderately strong and show little or no gloss. Measurements given 

 by him of 201 eggs in the United States National Museum are as fol- 

 lows: Average 32.54 by 22.86 millimeters; largest 37.84 by 26.42; 

 smallest 27.94 by 21.59. 



The average weight of 17 eggs was given by Bergtold (1917) as 

 0.34 ounces, or 9.64 grams. Weights of 13 eggs, in two sets, given by 

 the same writer ranged from 132 to 155 grains (8.58 to 10.07 grams). 

 The average for the whole lot of 13 eggs was 9.39 grams. An egg 

 studied by me in Smoky Valley, Nev., which contained a well-developed 

 embryo, measured 31 by 24 millimeters and weighed 7.2 grams. An- 

 other (incubation estimated at 14 days) measured 37 by 23 millimeters 

 and weighed 8.2 grams. 



Young. — Bendire (1895) gives the length of the incubation period 

 as 16 to 18 days. He observed that one egg is deposited daily, and 

 that incubation does not begin until the full set is nearly completed. 

 Wheelock (1904), apparently on the basis of original observations, 

 wrote that the female incubates for 18 days. 



Opportunity came to me in several seasons to study young magpies 

 in various stages of development in Smoky Valley, central Nevada. 

 Three young, just hatched on May 16, had colorless skins that appeared 

 pinkish because of the blood showing through them. Each was weak 

 and barely able to raise its head and open its bill. When first taken 

 from the nest they made a few weak squeaks. The brooding parent 

 allowed approach to within 50 yards and then flew off with a series of 

 about eight loud, harsh calls. It did not return, but this one or an- 

 other continued the alarm from a spot 150 yards away. At another nest 

 in similar stage the brooding bird flew off silently at approach within 

 75 yards. 



When removed from a nest two young magpies that had grown to 

 more than ten times their bulk at hatching at first uttered loud food 

 calls and opened their bills. Soon an adult came and gave sharp calls, 

 whereupon the young became quiet and the parent moved away. Later, 



