| 
(Syncerus caffer), steinbuck (Raphicerus cam- 
pestris), and common zebra (Equus burchel- 
lit). 
In more recent studies, there is a general 
trend to gather more detailed information 
about food supplies and feeding activities of 
the animal. Good examples of studies on forag- 
ing animals to illustrate this point include the 
work on pocket gophers by Ward and Keith 
(1962), on deer by Korschgen (1962) and 
Chamrad and Box (1968), on sheep by Heady 
and Torell (1959), on steers by Galt et al. 
(1966), and on sheep and cattle by Van Dyne 
and Heady (1965). It is difficult to judge the 
real significance of diet composition without 
detailed information on availability and re- 
lated factors. When more detailed information 
is gathered on what foods are available in the 
areas used, it is much easier to identify food 
particles and to interpret results. 
COLLECTING AND PRESERVING THE 
SAMPLE 
Records of Sample 
For any study of food habits it is desirable 
to have a record card printed for convenience 
in tabulating data. The author has found the 
5- by 8-inch manila card with double holes 
punched around the periphery to be satisfac- 
tory. In some cases, the use of overlay templates 
with standard forms and optical mark page 
readers as described by Loveless (1966) could 
be used. 
Care of Sample 
Collection and storage of samples can play 
an important part in the success of a study. 
Complete records of collection data are usually 
kept with the sample by the use of vulcanized- 
fiber-paper labels or tags. Plastic bags of good 
strong quality make ideal containers for all 
types and sizes of stomach contents and feces. 
Materials that can be examined within 24 
hours generally need no preservation. If con- 
tents can be washed and dried, they can be 
stored for long periods. Preservation of food 
materials by refrigeration is recommended. 
Portable ice chests and styrofoam boxes can be 
used in the field, and food freezers can be used 
in the laboratory. Freezing has the special ad- 
vantage of preserving both color and texture. 
Formalin is the most reliable and economical 
chemical preservative. Small-to-medium-sized 
stomachs should be preserved with a 4 percent 
solution of formalin (commercial formalin di- 
luted with 25 parts of water). A stronger pre- 
servative, such as 8 percent formalin, is needed 
for larger specimens. Care should be used in 
handling formalin so that it does not contact 
the skin or eyes. Specimens preserved in for- 
malin can be handled safely after placing them 
for 3-5 minutes in a deformalizing solution 
prepared from 1 gallon of tap water, 252 
grams of sodium bisulfite (NaHSO,), and 168 
grams of sodium sulfite (Na.SO,). 
The importance of methods and timing of 
stomach content collections from herbivores 
and birds will be covered by Medin (1968) in 
this conference. 
For fecal analysis, collection must be re- 
stricted to fresh fecal materials. Studies have 
shown that it takes from a few hours to 
10 days for food to pass through herbivores. 
Due to weathering of fecal materials in the 
field, it is desirable to collect fecal samples 
from observed animals. This will eliminate 
mistakes in aging, and destruction of plant 
parts by insects, bacteria, and fungi. It will 
also permit collection from individual animals. 
The fecal material should be stored in plastic 
bags to prevent drying. Refrigeration is an 
ideal way to store samples. It keeps the materi- 
al fresh and avoids hardening and molding. 
Since there is usually a large supply of each 
sample available, only a subsample is collected. 
Analytical procedures prohibit examination of 
all materials, and storage becomes a problem if 
large samples are collected. For practical rea- 
sons, sample data collected from many differ- 
ent fecal groups are more valuable than de- 
tailed examination of all material in one drop- 
ping. By mixing the fecal material and picking 
random subsamples, a representative sample 
can be obtained in the field. Further subsam- 
pling and mixing is done in the laboratory. 
IDENTIFYING PLANT PARTICLES 
Equipment 
Good microscopes are essential for food-hab- 
its analyses. The widefield, par-focal dissecting 
binocular scope with both the fixed stand and 
the horizontal, swing arm mounted on a heavy 
base is recommended. A compound micro- 
scope will be necessary for conducting studies 
where plant microtechniques and histology are 
required. 
When purchasing microscopes, include the 
camera accessories so that photomicrographs 
can be taken. Polaroid cameras work very well 
for developing a reference collection of pho- 
tomicrographs. The 35-mm. cameras, with a 
fine-grain film, are good for making photomi- 
crographs where several prints of the same 
photo are desirable. The new single-lens cam- 
eras with built-in light meter are ideal for this 
kind of work. All the major microscope compa- 
nies have the necessary accessories to adapt 
the ordinary 35-mm. field camera to their mi- 
croscopes. 
147 
