In addition to productivity studies, a number of 

 waterfowl were placed in enclosures of predeter- 

 mined size in order to approximate summer uti- 

 lization. Results showed that, in summer, ducks 

 take a high percentage of the seeds produced, but 

 their consumption of vegetative parts and of 

 tubers was not extensive. 



Ecology of wetland timber impoundments. — 

 The. New York Unit's research on plant succes- 

 sion, waterfowl use, and waterfowl productivity 

 on Montezuma National Wildlife Refuge lias been 

 greatly facilitated by the development of an auto- 

 matic sequence camera, giving photographic sur- 

 veillance of randomly selected plots for the entire 

 daylight period. Three such cameras were in op- 

 eration during the late summer and early fall of 

 19G3 and obtained a total of 60 observation-days in 

 this initial attempt. Minor technical problems 

 have been encountered in the operation of the cam- 

 eras; however, a completely transistorized circuit 

 was developed during the winter quarter, and 

 promises to make the camera even more useful. 





OTHER MIGRATORY BIRDS 



Migratory birds other than waterfowl of special 

 concern to the Bureau include mourning doves, 

 woodcock, wild pigeons, various shore birds, and 

 sandhill and whooping cranes. The whooping 

 crane is threatened by extinction; the other groups 

 are of particular recreational importance. 



National mourning dovt breeding survey. — The 

 breeding population of the mourning dove in the 

 I'nited States is censused in a national cooperative 

 effort in late May and early June each year by Bu- 

 reau and State personnel. The data obtained are 

 used to compute indexes to breeding populations 

 in the three mourning dove management units. 



* . * *».. 



one of 60 "photographic plots" established by the New Jork t'nit on the Montezuma National Wildlife Refuge. 

 Automatic-sequence cameras are mounted at sampling locations t<> obtain a measure of duck use at different periods 



of the i>r ling and rearing seasons. The camera, in the waterproofed open-end i«>x on the pole, is set to begin 



photographic surveillance of the plot at daylight the next morning, taking 1 picture every 15 minutes. (Photo by 



Daniel Q. Thompson) 



24 



