Mo 1. 13, No. 8 
Page 2 
populations for the fall of 1970, based on these regression formulae, are 21.6 
quail per 100 acres on the Forbes Area and 41.7 quail per 100 acres on the Dale 
Area. These data indicate a 17 percent lower population density for both areas 
than in 1969 * 
5. Responses of Prairie Ch i ckens to Hab i tat Man i pu 1 at ion R. L. Westemeier 
During the spring of 1970, approximately 324 people visited the prairie 
chicken sanctuaries in Jasper County on a reservation basis. In addition, an 
unknown number of people who made no reservations visited the sanctuaries. The 
numbers of guided visitors in 1966 , 1967, i 960 , and 1969 were 56 , 34, 159, and 
225, respectively. Thirty-three groups and 24 mornings were involved this spring. 
Groups represented included the following: Newton High School, about 90 individuals 
Illinois Audubon Society, 27; Champaign Centennial High School Conservation Club, 
26; Champaign County Audubon Society, 26; Indiana University, Bloomington, 18; 
Prairie Chicken Foundation of Illinois, 15; Eastern Illinois University, 15; Great 
Lakes Chapter, Sierra Club, 15; Western Illinois University, 14; Southern Illinois 
University, 13; Olney Central College, 12; Prairie Grouse Committee, 9; University 
of Illinois, 9; Illinois Natural History Survey, 3; Illinois State University, 
Normal, 5; Effingham D.A.R-, 4; University of Illinois, Extension, 4; Illinois 
Department of Conservation, 2; University of Sweden, Stockholm, 2; and 10 other 
ornithologists, sportsmen, and interested individuals. These data attest to the 
growing interest in the preservation of prairie chickens in Illinois. 
Included among the 324 visitors in 1970 were 137 individuals who assisted the 
research project materially by spending 192 man-mornings in blinds. These observers 
produced 46 detailed records of booming ground activity, each of which covered at 
least a 2-hour period on a booming ground. 
6. Rabbit Management 0. B. Rose 
The energy consumed per day by cottontail rabbits in outdoor pens and in 
outdoor cages was measured as described in MV/RL 13(2):4— 5, from mid-February 
through mid-August, 1970. Food consumed per day by the rabbits in the cages was 
negatively correlated with air temperature. The relationship is expressed in the 
equation Y = 98.49 + 0-542X, when X is the mean air temperature for the experimental 
period, and Y is the number of grams of rabbit chow consumed per day. However, food 
consumption by the penned cottontails was not significantly correlated with air 
temperature for the time period from mid-February through mid-August. 
In general, the energy required by homoiothermic animals for thermoregulation 
decreases as their zone of thermoneutrality (the range of temperatures at which 
no energy is expended for maintenance of body temperature) is approached, hence 
the decreasing trend in energy utilization by the caged rabbits. The reason for 
the failure of the penned animals to reduce energy utilization is not known, but 
may be a result of increased activity in summer or of changes in endocrine 
function during the breeding season. Since caged cottontails do not breed, such 
changes would not influence their energy utilization. 
