80 Birds of Colorado 



Distribution. — Temperate North America from Newfoundland and 

 British Coliimbia south to the West Indies and Guatemala ; breeding 

 throughout the greater part of its range, but in the northern half only 

 a summer resident. Occasionally in Europe. 



In Colorado the Bittern is a fairly common summer bird, arriving 

 early in May and breeding in the plains and foothills up to about 

 8,000 feet. Felger saw one as late as December 28th, near Fort Morgan, 

 so a few may perhaps spend the winter in the State. Carter found it 

 nesting in Middle Park at about 7,000 feet, and A. D. Baker in the Wet 

 Mountain Valley at about 8,000 feet (Cooke). On the western slope 

 it has been noticed by Sullivan near Grand Junction in summer, but 

 he did not succeed in finding the nest. Other records are Fort Lyon, 

 April 26th, and Loveland, May 13th (Cooke), Boulder co., plains 

 (Henderson), Barr, common summer resident, breeding (Hersey & 

 Rockwell), near Colorado Springs, May 15th and October 5th (Aiken), 

 Crested Butte, in the fall (Warren), Sahda, April (Frey). 



Habits. — The Bittern is a singular bird, found solitary 

 or in pairs in swamps and marshes. It is very deliberate 

 in its movements, and has marvellous powers of con- 

 cealment. It simply stands still with bill and neck 

 vertically upraised, when the striped plumage so com- 

 pletely harmonizes with the surroundings that it is 

 practically invisible. It is also noted for its astonishing 

 vocal performance. This resembles the working of an old- 

 fashioned pump, or even in the same bird the driving of 

 a stake into a bog. From this it is sometimes known as 

 the " Thunder-pumper " or " Stake-driver," The noise 

 can be heard a long way off, and is caused by inflating 

 the throat and emitting the air with a gulping motion. 



The food of the Bittern consists of frogs, small fishes, 

 and aquatic insects, which are usually obtained by 

 spearing with the sharp-pointed bill. 



The nest is generally placed on the ground in or near 

 marshes ; it is built up chiefly of rushes. The eggs, 

 3 to 4 in number, are brownish drab, oval in shape, 

 and measure 2*0 x 1*48, Dille gives June 20th as the 

 average time for fresh eggs in northern Colorado. 



