634 U.S. NATIONAL MUSEUM BULLETIN 237 part 2 



three. There is a single record of a clutch of five eggs, apparently 

 for P. a. dumeticolus (H. Brown, 1903). 



The eggs are generally ovate, though elliptical or elongate-ovate 

 examples are found occasionally. Characteristically their ground 

 color is a plae clay blue, and Bendire (1890) thought it to be paler 

 than that of the eggs of either Pipilo fuscus crissalis {seniculat) or 

 P. j. albigula. The markings of the eggs of Abert's towhees are 

 sparse but well defined. They are usually heaviest about the larger 

 end, and are dark brown in color. Eggs with almost black markings 

 occur occasionally. Some have been described with brown markings 

 bordered by vinaceous and rufous. Infrequently the markings, 

 whatever their color, are connected by fine pigmented lines. Paler 

 shell markings of lavender or purple have been described in some 

 eggs. 



Measurements of 83 eggs of P. a. aberti yielded the following data- 

 mean dimensions, 0.94 by 0.70 inches (23.8 by 17.8 millimeters); 

 largest egg in the series, 1.08 by 0.70 inches (27.4 by 17.8 millimeters); 

 and smallest egg in the series, 0.82 by 0.69 inches (20.8 by 17.5 milli- 

 meters). Brewster's (1882a) measurements of three eggs fall within 

 these ranges. 



W. G. F. Harris writes: "The Abert's towhee usually lays three or 

 four slightly glossy eggs, sometimes only two and less frequently five. 

 They are ovate or short-ovate and practically indistinguishable from 

 those of the canon towhee. The ground may be very pale greenish or 

 creamy white with scattered spots and scrawls of black and very dark 

 bro^vns such as 'chestnut brown,' 'Carob brown,' or 'mummy brown,' 

 with undermarkings of 'light neutral gray,' or 'dark purplish gray.' 

 The eggs generally are rather sparingly marked, and mostly toward 

 the large end. Often a loose wreath is formed of small black scribblings 

 interspersed wdth a few gray spots. The measurements of 50 eggs 

 average 24.1 by 17.8 millimeters; the eggs showing the four extremes 

 measure 27.7 by 17.3, 23.4 by 19.3, 20.8 by 17.5, and 25.4 by 16.3 

 millimeters. The measurements of 17 western Abert's towhee eggs 

 average 24.8 by 18.2 millimeters; the eggs showing the four extremes 

 measure 27.3 by 19.9, 23.3 by 18.2, and 25.1 by 17.3 millimeters." 



Plumages. — The following information on the molts and plumages 

 of all the brown towhees (Pipilo fuscus, Pipilo albicollis, and Pipilo 

 aberti) is taken directly from John Davis (1951): 



The molt pattern of the brown towhees has been determined through the study 

 of fall-taken specimens, the ages of which were ascertained by the degree of skull 

 ossification. The only molt of real significance in the brown towhees is the fall 

 molt. At this time adults undergo complete feather replacement. Birds under- 

 going the postjuvenal (first fall) molt retain the primaries and secondaries, and 

 usually the rectrices. This molt pattern offers plumage characters that may be 



