MONTHLY WILDLIFE RESEARCH LETTER 
Department of Conservation and Natural History Survey, Cooperating 
T. G. Scott, Editor 
Urbana, Illinois 
April I960 
Vol. 3, No. 4 
W-30-R-13 R. F. Labisky 
Within the past 20 years, much emphasis has been placed on provision of 
woody cover to increase habitat for pheasants and other wildlife species. What 
effect has the development or restoration of woody cover had on pheasant popula¬ 
tions? As one example, let us evaluate the specific effects of habitat improvement 
plantings on the Urbana Township area in Champaign County, Illinois. Beginning 
in 1940 and ending in 1941, as many habitat-improvement plantings were made on the 
2,560-acre area as were permitted by the landownex'S. Four types of habitat 
developments were installed: 2.1 miles of fencerow improvements, 1.4 miles of 
stream bank plantings, 0.2 miles of improved w>odlot borders, and 1.7 acres of 
block plantings. The principal shrub species that were planted included multi¬ 
flora rose, honeysuckle, dogwoods, and elderberry; the tree species included red 
pine, red cedar, arborvitae cedar, Norway spruce, black locust, and Russian olive. 
As of 1947, pheasant populations on the development area had not changed appreci¬ 
ably from the initial census in 1939-40, when the winter population numbered 69 
birds. The pheasant population on the development area followed the same trends 
as did the population on a nearby 3-square mile control area. Recent knowledge 
of pheasant populations indicates that populations on the experimental area have 
changed but little since 1947. Thus, there does not appear to have been a sig¬ 
nificant advantage to the development of woody cover on the Urbana Township area 
as far as pheasants are concerned. The 1947 studies did show that the cover 
plantings provided excellent songbird habitat; rabbits were also benefited by 
the cover plantings. 
W-42-R-9 R. D. Lord, Jr. 
Analysis of the age of 1,300 rabbits collected monthly from July, 1956, 
to December, 1959, reveals that the average life expectancy of a rabbit at birth 
is 6.4 months. Of the total sample, the oldest rabbit was 38 months old. Seventy- 
five per cent of the rabbits born do not live to attain the age of 4 months. 
The annual cycle of abundance shows a fivefold increase in the rabbit 
population from March, the month of lowest populations to June and July, the 
months of peak populations. Two-thirds of the mid-summer population dies by 
the opening of the hunting season. 
Rabbits born in March, April, and May have a much lower probability of 
surviving to 12 months of age than do those born in June, July, August, and 
September. Rabbits born in May, June, July, and August comprise three-fourths 
of the hunter's bag. 
