376 BULLETIN 195, UNITED STATES NATIONAL MUSEUM 



nests of this species and those of the mockingbird and curve-billed 

 thrasher. 



There are four sets of eggs of Sennett's thrasher in my collection, 

 one of which is said to have come from a nest in a mesquite bush, made 

 of thorny twigs and lined with grass and straws. 



Eggs. — Sennett's thrasher apparently lays anywhere from two to 

 five eggs to a set, four being the commonest number. What eggs I 

 have seen are practically indistinguishable from those of the brown 

 thrasher; they are ovate in shape and finely sprinkled with "cinna- 

 mon" over a bluish-white or greenish-white ground. Mr. Sennett 

 (1878) says: "The usual complement of eggs is four; in fact, I found 

 only one clutch of five. * * * The typical ^gg has a ground-color 

 of the faintest greenish-white, and is finely speckled all over with 

 brown, the dotting being thickest at the larger end. Several sets 

 were obtained with the ground-color yellowish- white, and so thickly 

 speckled as to have a general color of ochre. One set is nearly pure 

 white, speckled thickly only in the form of a wreath at the larger 

 end, otherwise very sparsely and faintly marked." He says else- 

 where (1879) that four eggs "were usually laid in the first clutch in 

 April, while second clutches, late in May, contained generally three." 



Dr. J. C. Merrill (1878) writes: "The usual number of eggs is three, 

 often two, more rarely four: the ground-color varies from greenish 

 to reddish-white, more or less thickly sprinkled with reddish and 

 brownish dots and spots. One set is sparingly covered with large 

 clouded blotches, giving the eggs an appearance unusual in this genus." 



The measurements of 50 eggs average 27.3 by 19.8 millimeters ; the 

 eggs showing the four extremes measure 30.0 by 20.3, 29.5 by 21.3, 24.4 

 by 18.8, and 27.4 by 18.3 millimeters. 



Plumages. — The sequence of molts and plumages is evidently the 

 same as with the brown thrasher. The young bird in ju venal plumage 

 is much like the adult, but the rump is paler and indistinctly streaked 

 with dusky ; the blackish streaking on the under surface is less clearly 

 defined ; and the whole body plumage is softer and looser. 



Food. — Cottam and Knappen (1939) analyzed the stomach contents 

 of three Sennett's thrashers and reported the following items : Ant- 

 lions, 4 percent (one bird had consumed eight larvae of these peculiar 

 insects) ; termites 1 percent; grasshoppers, locusts, etc., 5 percent 

 (some obtained by each bird) ; stink bugs, 9 percent; miscellaneous 

 true bugs, 6.67 percent, formed a part of each meal; beetles, 30 per- 

 cent; Tenebrionidae, 30 percent; ants, 13.33 percent; other Hymenop- 

 tera, 1 percent; moths, 11.67 percent; miscellaneous insects, 2.67 per- 

 cent; spiders, 2.67 percent; centipedes, 1.67 percent; fragments of a 

 small frog, 1.33 percent; fruit of hackberry, 7.33 percent; undeter- 

 mined plant fiber, 2.66 percent. One bird made 23 percent of its last 

 meal on hackberries. 



