364 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. IX. 



He would extend his neck, then drawing in his head suddenly, would 

 throw it out with a jerk as if he were affected with violent nausea 

 or were trying to get rid of some obstruction in his throat, at the same 

 time uttering the peculiar pump-er-lunk. After repeating the move- 

 ment and its accompanying vocal notes several times in rather quick 

 succession, he would stand nearly erect for a few moments before 

 beginning again. As he stood with his back partly towards me, I 

 could not see his breast or throat distinctly, but I am sure he did not 

 fill the latter with water while I was watching him, for not once did 

 his bill descend low enough to get even a hurried sip." 



The writer has on one occasion had the pleasure of observing 

 this interesting performance, and can add his testimony to the effect 

 that the bird in question did not at any time lower his bill below the 

 level of the body, certainly not low enough to reach the water, which 

 at that place, upon later investigation, proved to be about two inches 

 deep. 



Genus IXOBRYCHUS Billberg. 



80. Ixobrychus exilis (GMEL.). 

 LEAST BITTERN. 



Ardetta exilis (Gmel.), A. O. U. Check List, 1895, p. 70. 



Distr.: Temperate North America, from British Provinces south 

 to West Indies and South America; less common on the Pacific 

 coast. 



Adult male: Crown of the head, black, extending into a small crest; 

 back and tail, black, with a greenish tinge back of the neck; wing 

 coverts, chestnut brown; some of the wing coverts, tawny yellow; 

 front and sides of the neck and under parts, yellowish brown, showing 

 white on throat; a patch of brownish black on the sides of the breast; 

 bill, yellowish, dusky on the top; legs, green, yellow on the back; 

 toes, yellow. 



Adult female: Having the back and crown purplish chestnut 

 instead of black. 



Length, 12.50; wing, 4.50; bill, 2; tarsus, 2.10. 



The Least Bittern is a common summer resident in Illinois and 

 Wisconsin, breeding throughout both states in suitable localities. 

 The nest is usually built in rushes and reeds in ponds or marshy 

 places, rarely in bushes. The eggs are bluish white, from 4 to 7 in 

 number, and measure 1.20 x .95 inches. The Field Museum possesses 

 several sets of eggs of this species taken in the vicinity of Calumet 

 Lake, Chicago, between June isth and June 2gth. 



