Comparisons of ground and aerial counts during 1960-64 

 indicated that helicopter surveys, flown for complete coverage 

 following snowfall in early winter when most deer used open 

 ridgetop habitat, provided an effective method for determining 

 numbers and sex and age composition of mule deer on the study 

 area. Because of a need for continuing information on 

 population characteristics and trends in management of mule 

 deer in breaks habitat, and termination of intensive studies, 

 the helicopter surveys became the primary method of study 

 during the second, extensive phase. 



Early winter surveys were conducted in most years from 

 1964 through 1975. Exceptions included 1968, 1969, when 

 classification counts were made by the area management 

 biologist with a fixed-wing aircraft, and 1972, when mild, dry 

 weather precluded flying until late winter. Overall, these 

 data provided estimates of population size and composition and 

 trends in relation to range/environmental conditions 

 throughout the period (Mackie 1973, 1976). 



Measurement of utilization and condition trends of major 

 browse species was also continued in spring of each year on 

 established transects. In addition, 5 permanent 

 point-center-quarter transects measuring shrub composition, 

 density, and plant size were established on the area during 

 1971 as part of a study of ecological characteristics of 

 fragrant sumac in Montana (Martin 1972). 



Mule deer harvests were monitored in a limited manner 

 through field reconnaissance during hunting seasons and the 

 statewide harvest survey for the hunting district which 

 includes the area. 



During 1972-1975, 2 graduate thesis research studies were 

 completed on our supplementary Nichols Coulee Resource 

 Conservation Area (NCRCA) study area (Knowles 1975, Komberec 

 1976). Designed to evaluate range relationships of mule deer 

 and elk within a rest-rotation grazing system, these studies 

 included aerial population surveys similar to those conducted 

 on our primary study area and use of marked and radio-collared 

 deer in studies of habitat use. 



Recent Studies 



The third phase, beginning in 1975, was precipitated by 

 the failure of existing knowledge and theory about mule deer 

 habitat relationships and population dynamics to explain 

 population phenomena observed on the study area and elsewhere. 

 Our study area and the 15 years of baseline data available 

 provided exceptional opportunity to conduct the intensive, 

 long-term population studies we believed necessary to develop 

 an improved understanding of the process and mechanics of 



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