80 Birds of Colorado 
Distribution.—Temperate North America from Newfoundland and 
British Columbia 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), Salida, 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 ag the 
average time for fresh eggs in northern Colorado. 
