1921] STODDARD, A SPRING TRIP TO THE WISCONSIN RIVER. 37 



were present in considerable numbers and late in the afternoon we lo- 

 cated a joint nesting colony of these interesting birds and Great Blue 

 Herons. Just why these two species chose to nest in the same trees, as 

 shown in figure 17, when they had thousands to select from, is a mys- 

 tery, but here they were, the huge nests of the Herons in the slender 

 top limbs and the smaller nests of the Cormorants in the heavy forks 

 lower down. Hundreds of Cormorants were about, most of which were 

 migrants on their way north, and eight extra fine specimens were taken. 

 We had a lively time with them as they are as hard to kill as geese, and 

 swim long distances under water when injured. A month later we were 

 successful in obtaining fine group material here. 



On this first trip there were literally thousands of Canada Geese in 

 the flooded area and we worked hard to collect a few. A few days 

 later when another trip was made with good equipment for taking them, 

 we found that they had left for the north. As it was now sundown and 

 we still had twelve miles to row against the wind and wave, the "wild 

 goose chase" was abandoned for the time being, and we bent to the oars, 

 arriving at Gastrow's farm at nine in the evening. For two weeks I had 

 good cause to remember the trip, as a badly swollen wrist resulted. On 

 this trip an Evinrude motor would have saved the day. 



As it was necessary to keep a close watch on the nesting Cormorants, 

 many subsecjuent trips were made to this unique lake. 



Previous to leaving the Museum we had discussed the desirability of 

 collecting a number of Prairie Chickens to illustrate in group form the 

 curious habit of these birds of meeting mornings and evenings in spring 

 to "coo," strut, fight, and otherwise perform. Here at Prairie du Sac 

 it was found that such material could be collected to good advantage on 

 the barren west end of Sauk Prairie where, Mr. Ochsner says, that, to 

 his certain knowledge, these birds have gone through their antics on a 

 particular knoll for thirty years. We made about twenty trips to this 

 place and succeeded in gathering the necessary data and specimens 

 (eight fine roosters) for the group. 



The birds appeared on the grounds before daylight, two mornings 

 that we tried to beat them to it, and performed about two hours, and an 

 equal length of time late in the evening. The roosters take up well 

 trodden stands, each a few feet from his nearest rival. After a few 

 preliminary jumps high in the air, as if to take the stififness out of his 

 legs, the cock is ready to "coo". The head is lowered and neck stretched 

 well out, wings drooped, tails spread and cocked slightly forward, long 

 neck tufts vertically erected, and the ornamental eye patches of bright 



