Vo). 10, No. 5 
Page 3 
Seventeen cocks were found on two areas added to the annual censusing effort this 
spring. On 19 areas which also were censused in 1966, 162 cocks were found in 
1967, 11 percent less than the 182 cocks found on the same areas in 1 966 . Increased 
population levels since 1966 were recorded for four areas: (l) near Bogota in 
Jasper County, (2) near Farina and (3) Stephen A. Forbes State Park in Marion 
County, and (4) near Martinsville in Clark County. However, decreases were evident 
on 10 areas, and no change took place on 2 areas, I of which was the Hunt Area in 
Jasper County, where only one cock was found in both 1 966 and 1967 . No prairie 
chickens were found in the spring of I 967 on 5 of the 21 census areas, 3 of which 
were already defunct in 1966 . 
On 10 areas where censuses were initiated in 1 963 there were 59 percent fewer 
prairie chickens observed in 1967 than were observed in 1 963 . Statewide population 
losses between 1 963 and 1964, between 1964 and 1965, between 1 965 and 1966, and 
between 1966 and 1967 were 16, 35* 34, and II on respective percentage bases. 
Although these data show a continuing downward trend, on a statewide basis, the 
most recent loss is of a lower magnitude than the three earlier declines. Since 
increased population levels were recorded on four census areas, it appears that 
the 1966 breeding season was relatively successful on some local areas in spite 
of limited acreages of nesting cover. 
6 . Rabbit Management j. a. Bailey, J. C. Hanson 
Autopsies of I 67 cottontail rabbits collected during a 26-month period revealed 
that the left adrenal gland was heavier than the right in I 65 of 167 cases. In one 
case the adrenals had equal weights and in one case the right adrenal was heavier. 
Biologists studying stress in mammals frequently weigh adrenal glands, usually 
reporting total weights for pairs of glands. Since data may be wasted when an 
animal with one damaged adrenal is autopsied, it would be useful if the weight of 
the damaged adrenal could be predicted from the weight of its undamaged correlate. 
Accordingly, the weights of 1 67 pairs of adrenal glands were analyzed by linear 
regression procedures. 
The 167 rabbits were either autopsied fresh or after they had been frozen. 
Adrenals were removed, cleaned of associated tissue, blotted on moist paper, and 
weighed. Average weight of the left adrenals was 109-6 mg; of the right adrenals, 
83-9 nig. Regression formulae were as follows: Left adrenal = -I .9 + I .33 times 
the weight of the right adrenal; right adrenal = 6.2 + 0.71 times the weight of 
the left adrenal. 
