GREATER PRAIRIE CHICKEN" 247 



during the rainy period of the year. One such island of about 100 

 acres near Bancroft, Wis., is called Prairie Chicken Island, because 

 these birds have always lived and nested there in unusually large 

 numbers. 



Since agriculture has been encroaching on the original habitat of 

 the prairie chicken, many of the birds have adapted themselves with 

 more or less success to conditions created by farming activities. A 

 nest of the prairie chicken was found on June 24, 1929, on a farm 

 10 miles northeast of Friendship, Adams County, Wis. The nest 

 was on rather high meadowland and was completely surrounded 

 with a luxuriant growth of clover, timothy, and other grasses. The 

 eggs were well concealed by a beautiful canopy of red-clover 

 blossoms. The bowl of the nest measured 15 by 19 centimeters in 

 diameter but only 4 centimeters in depth. The lining of the nest 

 consisted of grasses and weed stems, all apparently picked up from 

 the vicinity of the nest. The clover field was bordered on one side 

 by a low, wet marsh, in which various sedges and rushes prevailed ; 

 on the other side was a cleared area being used as a potato field. 



Other individuals cling to the more remote prairie districts away 

 from farms, often in situations occupied in common with the sharp- 

 tailed grouse. A nest containing 11 eggs was found in such a situa- 

 tion in Portage County on June 17, 1929. It was placed among 

 tufts of sedge (Carex stricta). The nesting cavity was 18 by 21 

 centimeters in diameter and 8 centimeters deep. The lining of the 

 nest was made up entirely of sedge, among which were a few 

 feathers of the incubating bird. Near the nesting site was a low, 

 wet marshy area, and on the other side there were thickets of small 

 willows and poplars. No farmland or farm buildings were within 

 3 miles of this location. 



Eggs. — The background color of the eggs varies from a " dark 

 olive-buff " to a " grayish olive " tint. Most of the eggs are dotted 

 with many fine and a few larger spots of " sepia." The spotting 

 varies considerably in different eggs from those with scarcely any 

 marks to those with many fine dots and 20 or more well-defined spots 

 ranging from 1 to 2 millimeters in diameter. Sets of eggs found in 

 open prairie regions seemed to have less spotting and the color of 

 the spots was a " vinaceous-buff " rather than the dark markings of 

 " sepia " present on eggs found in nests located in the wooded 

 sections of the State. This difference in coloration, however, is 

 probably a mere coincidence and is not to be correlated with a con- 

 sistent difference in habitat. 



Nine sets comprising 100 eggs, all found in central Wisconsin 

 during the summer of 1929, were weighed and measured. The 

 average long diameter was 44.86 millimeters; average short diameter, 



