than a year ago,” and he advised that “The Rock- 
ford range shows all the preliminary symptoms of 
impending overpopulation.” 
Developments taking place since Leopold’s 
surveys reveal that he underestimated the pos- 
sibilities of the deer for expansion into unoccu- 
pied parts of the Rock River range. Nonetheless, 
his foresight concerning deterioration of the range 
near Rockford proved correct. 
Cheatum (1949:19, 22) demonstrated a cor- 
telation between weight loss in deer and fat 
reduction in the marrow of the femur of the an- 
imals; he observed that a serious stage of mal- 
nutrition was indicated when less than 25 per 
cent by fresh weight of the femur marrow was 
composed of fat. He stated that some deer have 
been found dead with 20 to 25 per cent fat in their 
femur marrow, and he suggested that death usually 
tesults when the marrow fat is depleted below 15 
ot 20 per cent. 
In an effort to evaluate the extent of mal- 
nutrition among deer on the Severson and Funder- 
burg estates, the author collected marrow from the 
femur bones of six deer found dead in February 
and May of 1950, table 13. The results of fat 
analyses by the Department of Veterinary Pathol- 
ogy and Hygiene at the University of Illinois 
showed that the percentage of fat by weight in 
specimens 1, 2, and 6 was below the minimum 
survival level as indicated by Cheatum (1949:22) 
for most deer. The value found for specimen 6 is 
considered questionable because warm weather 
immediately prior to discovery of the carcass may 
have caused a loss of fat through the porous femur 
bone. These specimens were taken from animals 
that, judged by Cheatum’s criteria, were in an 
advanced stage of malnutrition at the time of 
death; specimen 4 was taken from a deer ina 
serious stage of malnutrition at the time of death. 
Table 13.- Fat analyses of marrow from the 
femurs of deer found dead on the Rock River range, 
Ogle and Winnebago counties, Illinois, winter and 
spring, 1950. 
; Date Per Cent of 
Specimen Carcass Fat by Weight, 
No. Found in Marrow 
1 2-12-50 ; 
2 2-25-50 13.4 
3 5-19-50 43.5 
4 | 5-19-50 | 23.8 
5 5-19-50 49.5 
6 | 5-31-50 8.3 
The proportion of fat remaining in specimens 3 and 
5 indicated that they were taken from deer that 
died from causes other than malnutrition. 
Deer in good physical condition undergo 
pelage changes atrather uniform times of the year. 
In West Virginia, the change from the winter to 
the summer coats normally begins in early March 
and continues into May (De Garmo et al. 1950:63). 
The change to the reddish summer coat is retarded 
in unhealthy deer. It is thought that the normal 
pelage changes on deer in Illinois occur at ap- 
proximately the same times as on deer in West 
Virginia, as weather conditions and latitudes of 
the two states are comparable. On the Severson 
and Funderburg estates, many deer still had 
partial winter coats as late as June 7 in 1950. 
Complete winter pelage was seen on a doe on 
June 15 and on a buck on June 19 of the same 
year. 
The only other Illinois herd known to have 
been in excess of the carrying capacity of its 
while this study was in progress, 
was that on the island of the Horseshoe Lake 
Game Refuge. A browse line was extremely 
obvious on the island, and the reproduction of 
acceptable woody plants was greatly retarded. 
environment, 
Sassafras, Sassafras albidum, and several species 
of dogwoods, Cornus spp., were eliminated so far 
as availibility to the deer was concerned. The 
sassafras trees that remained were large and 
their branches were far out of reach of the deer. 
In other parts of Alexander County, dogwoods and 
sassafras appeared to be the woody plants most 
sought after by deer. Trumpetcreeper, Campsis 
tadicans, which furnished some food for deer on 
the island of the Horseshoe Lake Game Refuge, 
was browsed less extensively. 
In the spring of 1950, eight dead deer were 
found on the island of the Horseshoe Lake Game 
Refuge. Marrow from the femur bones was col- 
lected from two of the animals; advanced decom- 
position had destroyed the marrow in the other 
six. Judged by the tooth development and wear 
ctiteria of Severinghaus (1949), one of the deer 
from which marrow was collected had reached old 
age, which presumably contributed to its death. 
Analyses of the collected samples revealed 29.6 
per cent fat by weight for the old animal and 14.2 
per cent for the other. Malnutrition was indicated 
as contributing to the death of the younger animal. 
On June 22, 1950, a large number of deer on 
the island of the Horseshoe Lake Game Refuge 
19 
